Leak Down test results
#11
Guest
Posts: n/a
Re: Leak Down test results
Chris,
When I originally did the valve seal change I was concerned about the
sound of air leaking as I had never had experience with putting air into the
cylinder to hold up the valves. So I did several examinations. I looked in
my radiator for bubbles (that doesn't pan out anyway as I'm not getting
water in the oil) and saw no bubbles. I put a sandwich baggie loosely over
the tail pipe with a rubber band to see if it would move the plastic, no
effect. Also, couldn't hear anything from the tail pipe. I put the valve
cover back on and took the hose from the pcv valve and put it up to my cheek
to feel for air, here I felt something. I forgot to close off the hose from
the valve cover to the air filter housing so I think if I did I would have
felt much stronger feeling through the pcv valve. However, I don't know if
this air is coming up through the valve guide or down through the cylinder.
I didn't test the oil dip stick for air.
Earlier, before the valve seal change I had a mechanic do a compression
test. The results were 150 psi across all cylinders. I double checked #1
and #2 on Tuesday (ran out of time to get the rest) and I got the same
results on both #1 and #2, 150 psi. So I confirmed the compression results
the mechanic had.
Bill
"c" <c@me.org> wrote in message
news:Y8CWb.1448$_66.869@twister.rdc-kc.rr.com...
>
> "William Oliveri" <wuji@bigvalley.net> wrote in message
> news:c0emre$1577m4$1@ID-193866.news.uni-berlin.de...
> > Offical Complete results of the Leak down test with the proper fitting
is
> as
> > follows:
> >
> > #1 -- 14.4%
> > #2 -- 24.5%
> > #3 -- 17.7%
> > #4 -- 11.1%
> > #5 -- 10.0%
> > #6 -- 13.3%
> >
> > Just for the record.
> >
> >
>
> Bill,
>
> When you tested #2 and #3 cylinder, did you check to see where the leakage
> was? #2 is a bit high and #3 is iffy. remember, a new engine can have as
> much as 8%, so the rest of them appear to be ok.
>
> Chris
>
>
When I originally did the valve seal change I was concerned about the
sound of air leaking as I had never had experience with putting air into the
cylinder to hold up the valves. So I did several examinations. I looked in
my radiator for bubbles (that doesn't pan out anyway as I'm not getting
water in the oil) and saw no bubbles. I put a sandwich baggie loosely over
the tail pipe with a rubber band to see if it would move the plastic, no
effect. Also, couldn't hear anything from the tail pipe. I put the valve
cover back on and took the hose from the pcv valve and put it up to my cheek
to feel for air, here I felt something. I forgot to close off the hose from
the valve cover to the air filter housing so I think if I did I would have
felt much stronger feeling through the pcv valve. However, I don't know if
this air is coming up through the valve guide or down through the cylinder.
I didn't test the oil dip stick for air.
Earlier, before the valve seal change I had a mechanic do a compression
test. The results were 150 psi across all cylinders. I double checked #1
and #2 on Tuesday (ran out of time to get the rest) and I got the same
results on both #1 and #2, 150 psi. So I confirmed the compression results
the mechanic had.
Bill
"c" <c@me.org> wrote in message
news:Y8CWb.1448$_66.869@twister.rdc-kc.rr.com...
>
> "William Oliveri" <wuji@bigvalley.net> wrote in message
> news:c0emre$1577m4$1@ID-193866.news.uni-berlin.de...
> > Offical Complete results of the Leak down test with the proper fitting
is
> as
> > follows:
> >
> > #1 -- 14.4%
> > #2 -- 24.5%
> > #3 -- 17.7%
> > #4 -- 11.1%
> > #5 -- 10.0%
> > #6 -- 13.3%
> >
> > Just for the record.
> >
> >
>
> Bill,
>
> When you tested #2 and #3 cylinder, did you check to see where the leakage
> was? #2 is a bit high and #3 is iffy. remember, a new engine can have as
> much as 8%, so the rest of them appear to be ok.
>
> Chris
>
>
#12
Guest
Posts: n/a
Re: Leak Down test results
Chris,
When I originally did the valve seal change I was concerned about the
sound of air leaking as I had never had experience with putting air into the
cylinder to hold up the valves. So I did several examinations. I looked in
my radiator for bubbles (that doesn't pan out anyway as I'm not getting
water in the oil) and saw no bubbles. I put a sandwich baggie loosely over
the tail pipe with a rubber band to see if it would move the plastic, no
effect. Also, couldn't hear anything from the tail pipe. I put the valve
cover back on and took the hose from the pcv valve and put it up to my cheek
to feel for air, here I felt something. I forgot to close off the hose from
the valve cover to the air filter housing so I think if I did I would have
felt much stronger feeling through the pcv valve. However, I don't know if
this air is coming up through the valve guide or down through the cylinder.
I didn't test the oil dip stick for air.
Earlier, before the valve seal change I had a mechanic do a compression
test. The results were 150 psi across all cylinders. I double checked #1
and #2 on Tuesday (ran out of time to get the rest) and I got the same
results on both #1 and #2, 150 psi. So I confirmed the compression results
the mechanic had.
Bill
"c" <c@me.org> wrote in message
news:Y8CWb.1448$_66.869@twister.rdc-kc.rr.com...
>
> "William Oliveri" <wuji@bigvalley.net> wrote in message
> news:c0emre$1577m4$1@ID-193866.news.uni-berlin.de...
> > Offical Complete results of the Leak down test with the proper fitting
is
> as
> > follows:
> >
> > #1 -- 14.4%
> > #2 -- 24.5%
> > #3 -- 17.7%
> > #4 -- 11.1%
> > #5 -- 10.0%
> > #6 -- 13.3%
> >
> > Just for the record.
> >
> >
>
> Bill,
>
> When you tested #2 and #3 cylinder, did you check to see where the leakage
> was? #2 is a bit high and #3 is iffy. remember, a new engine can have as
> much as 8%, so the rest of them appear to be ok.
>
> Chris
>
>
When I originally did the valve seal change I was concerned about the
sound of air leaking as I had never had experience with putting air into the
cylinder to hold up the valves. So I did several examinations. I looked in
my radiator for bubbles (that doesn't pan out anyway as I'm not getting
water in the oil) and saw no bubbles. I put a sandwich baggie loosely over
the tail pipe with a rubber band to see if it would move the plastic, no
effect. Also, couldn't hear anything from the tail pipe. I put the valve
cover back on and took the hose from the pcv valve and put it up to my cheek
to feel for air, here I felt something. I forgot to close off the hose from
the valve cover to the air filter housing so I think if I did I would have
felt much stronger feeling through the pcv valve. However, I don't know if
this air is coming up through the valve guide or down through the cylinder.
I didn't test the oil dip stick for air.
Earlier, before the valve seal change I had a mechanic do a compression
test. The results were 150 psi across all cylinders. I double checked #1
and #2 on Tuesday (ran out of time to get the rest) and I got the same
results on both #1 and #2, 150 psi. So I confirmed the compression results
the mechanic had.
Bill
"c" <c@me.org> wrote in message
news:Y8CWb.1448$_66.869@twister.rdc-kc.rr.com...
>
> "William Oliveri" <wuji@bigvalley.net> wrote in message
> news:c0emre$1577m4$1@ID-193866.news.uni-berlin.de...
> > Offical Complete results of the Leak down test with the proper fitting
is
> as
> > follows:
> >
> > #1 -- 14.4%
> > #2 -- 24.5%
> > #3 -- 17.7%
> > #4 -- 11.1%
> > #5 -- 10.0%
> > #6 -- 13.3%
> >
> > Just for the record.
> >
> >
>
> Bill,
>
> When you tested #2 and #3 cylinder, did you check to see where the leakage
> was? #2 is a bit high and #3 is iffy. remember, a new engine can have as
> much as 8%, so the rest of them appear to be ok.
>
> Chris
>
>
#13
Guest
Posts: n/a
Re: Leak Down test results
Chris,
When I originally did the valve seal change I was concerned about the
sound of air leaking as I had never had experience with putting air into the
cylinder to hold up the valves. So I did several examinations. I looked in
my radiator for bubbles (that doesn't pan out anyway as I'm not getting
water in the oil) and saw no bubbles. I put a sandwich baggie loosely over
the tail pipe with a rubber band to see if it would move the plastic, no
effect. Also, couldn't hear anything from the tail pipe. I put the valve
cover back on and took the hose from the pcv valve and put it up to my cheek
to feel for air, here I felt something. I forgot to close off the hose from
the valve cover to the air filter housing so I think if I did I would have
felt much stronger feeling through the pcv valve. However, I don't know if
this air is coming up through the valve guide or down through the cylinder.
I didn't test the oil dip stick for air.
Earlier, before the valve seal change I had a mechanic do a compression
test. The results were 150 psi across all cylinders. I double checked #1
and #2 on Tuesday (ran out of time to get the rest) and I got the same
results on both #1 and #2, 150 psi. So I confirmed the compression results
the mechanic had.
Bill
"c" <c@me.org> wrote in message
news:Y8CWb.1448$_66.869@twister.rdc-kc.rr.com...
>
> "William Oliveri" <wuji@bigvalley.net> wrote in message
> news:c0emre$1577m4$1@ID-193866.news.uni-berlin.de...
> > Offical Complete results of the Leak down test with the proper fitting
is
> as
> > follows:
> >
> > #1 -- 14.4%
> > #2 -- 24.5%
> > #3 -- 17.7%
> > #4 -- 11.1%
> > #5 -- 10.0%
> > #6 -- 13.3%
> >
> > Just for the record.
> >
> >
>
> Bill,
>
> When you tested #2 and #3 cylinder, did you check to see where the leakage
> was? #2 is a bit high and #3 is iffy. remember, a new engine can have as
> much as 8%, so the rest of them appear to be ok.
>
> Chris
>
>
When I originally did the valve seal change I was concerned about the
sound of air leaking as I had never had experience with putting air into the
cylinder to hold up the valves. So I did several examinations. I looked in
my radiator for bubbles (that doesn't pan out anyway as I'm not getting
water in the oil) and saw no bubbles. I put a sandwich baggie loosely over
the tail pipe with a rubber band to see if it would move the plastic, no
effect. Also, couldn't hear anything from the tail pipe. I put the valve
cover back on and took the hose from the pcv valve and put it up to my cheek
to feel for air, here I felt something. I forgot to close off the hose from
the valve cover to the air filter housing so I think if I did I would have
felt much stronger feeling through the pcv valve. However, I don't know if
this air is coming up through the valve guide or down through the cylinder.
I didn't test the oil dip stick for air.
Earlier, before the valve seal change I had a mechanic do a compression
test. The results were 150 psi across all cylinders. I double checked #1
and #2 on Tuesday (ran out of time to get the rest) and I got the same
results on both #1 and #2, 150 psi. So I confirmed the compression results
the mechanic had.
Bill
"c" <c@me.org> wrote in message
news:Y8CWb.1448$_66.869@twister.rdc-kc.rr.com...
>
> "William Oliveri" <wuji@bigvalley.net> wrote in message
> news:c0emre$1577m4$1@ID-193866.news.uni-berlin.de...
> > Offical Complete results of the Leak down test with the proper fitting
is
> as
> > follows:
> >
> > #1 -- 14.4%
> > #2 -- 24.5%
> > #3 -- 17.7%
> > #4 -- 11.1%
> > #5 -- 10.0%
> > #6 -- 13.3%
> >
> > Just for the record.
> >
> >
>
> Bill,
>
> When you tested #2 and #3 cylinder, did you check to see where the leakage
> was? #2 is a bit high and #3 is iffy. remember, a new engine can have as
> much as 8%, so the rest of them appear to be ok.
>
> Chris
>
>
#14
Guest
Posts: n/a
Re: Leak Down test results
Ok, I am curious...
Do you have any idea just what those numbers represent or mean? I
really don't.
I am taking a wild assed guess and am thinking those represent the shape
of the valve seats. You did say you had some play in the valve stems on
#2 right? This will make a strange oval wear pattern on the valve
seating area.
I mean the compression is way up there like a new engine, so things like
rings and gaskets are fine. The book says a new 258 should have 140-150
psi compression, but most important is even compression.
Your compression is 'perfect'.
It must be the seats of the metal parts that the leak down test
tests???
I honestly have never seen or heard of in person anyone doing that kind
of test. I have only heard about it on the internet and thought it was
a way to test a racing engine after a fresh rebuild like they do every
second race or so.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
William Oliveri wrote:
>
> Offical Complete results of the Leak down test with the proper fitting is as
> follows:
>
> #1 -- 14.4%
> #2 -- 24.5%
> #3 -- 17.7%
> #4 -- 11.1%
> #5 -- 10.0%
> #6 -- 13.3%
>
> Just for the record.
Do you have any idea just what those numbers represent or mean? I
really don't.
I am taking a wild assed guess and am thinking those represent the shape
of the valve seats. You did say you had some play in the valve stems on
#2 right? This will make a strange oval wear pattern on the valve
seating area.
I mean the compression is way up there like a new engine, so things like
rings and gaskets are fine. The book says a new 258 should have 140-150
psi compression, but most important is even compression.
Your compression is 'perfect'.
It must be the seats of the metal parts that the leak down test
tests???
I honestly have never seen or heard of in person anyone doing that kind
of test. I have only heard about it on the internet and thought it was
a way to test a racing engine after a fresh rebuild like they do every
second race or so.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
William Oliveri wrote:
>
> Offical Complete results of the Leak down test with the proper fitting is as
> follows:
>
> #1 -- 14.4%
> #2 -- 24.5%
> #3 -- 17.7%
> #4 -- 11.1%
> #5 -- 10.0%
> #6 -- 13.3%
>
> Just for the record.
#15
Guest
Posts: n/a
Re: Leak Down test results
Ok, I am curious...
Do you have any idea just what those numbers represent or mean? I
really don't.
I am taking a wild assed guess and am thinking those represent the shape
of the valve seats. You did say you had some play in the valve stems on
#2 right? This will make a strange oval wear pattern on the valve
seating area.
I mean the compression is way up there like a new engine, so things like
rings and gaskets are fine. The book says a new 258 should have 140-150
psi compression, but most important is even compression.
Your compression is 'perfect'.
It must be the seats of the metal parts that the leak down test
tests???
I honestly have never seen or heard of in person anyone doing that kind
of test. I have only heard about it on the internet and thought it was
a way to test a racing engine after a fresh rebuild like they do every
second race or so.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
William Oliveri wrote:
>
> Offical Complete results of the Leak down test with the proper fitting is as
> follows:
>
> #1 -- 14.4%
> #2 -- 24.5%
> #3 -- 17.7%
> #4 -- 11.1%
> #5 -- 10.0%
> #6 -- 13.3%
>
> Just for the record.
Do you have any idea just what those numbers represent or mean? I
really don't.
I am taking a wild assed guess and am thinking those represent the shape
of the valve seats. You did say you had some play in the valve stems on
#2 right? This will make a strange oval wear pattern on the valve
seating area.
I mean the compression is way up there like a new engine, so things like
rings and gaskets are fine. The book says a new 258 should have 140-150
psi compression, but most important is even compression.
Your compression is 'perfect'.
It must be the seats of the metal parts that the leak down test
tests???
I honestly have never seen or heard of in person anyone doing that kind
of test. I have only heard about it on the internet and thought it was
a way to test a racing engine after a fresh rebuild like they do every
second race or so.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
William Oliveri wrote:
>
> Offical Complete results of the Leak down test with the proper fitting is as
> follows:
>
> #1 -- 14.4%
> #2 -- 24.5%
> #3 -- 17.7%
> #4 -- 11.1%
> #5 -- 10.0%
> #6 -- 13.3%
>
> Just for the record.
#16
Guest
Posts: n/a
Re: Leak Down test results
Ok, I am curious...
Do you have any idea just what those numbers represent or mean? I
really don't.
I am taking a wild assed guess and am thinking those represent the shape
of the valve seats. You did say you had some play in the valve stems on
#2 right? This will make a strange oval wear pattern on the valve
seating area.
I mean the compression is way up there like a new engine, so things like
rings and gaskets are fine. The book says a new 258 should have 140-150
psi compression, but most important is even compression.
Your compression is 'perfect'.
It must be the seats of the metal parts that the leak down test
tests???
I honestly have never seen or heard of in person anyone doing that kind
of test. I have only heard about it on the internet and thought it was
a way to test a racing engine after a fresh rebuild like they do every
second race or so.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
William Oliveri wrote:
>
> Offical Complete results of the Leak down test with the proper fitting is as
> follows:
>
> #1 -- 14.4%
> #2 -- 24.5%
> #3 -- 17.7%
> #4 -- 11.1%
> #5 -- 10.0%
> #6 -- 13.3%
>
> Just for the record.
Do you have any idea just what those numbers represent or mean? I
really don't.
I am taking a wild assed guess and am thinking those represent the shape
of the valve seats. You did say you had some play in the valve stems on
#2 right? This will make a strange oval wear pattern on the valve
seating area.
I mean the compression is way up there like a new engine, so things like
rings and gaskets are fine. The book says a new 258 should have 140-150
psi compression, but most important is even compression.
Your compression is 'perfect'.
It must be the seats of the metal parts that the leak down test
tests???
I honestly have never seen or heard of in person anyone doing that kind
of test. I have only heard about it on the internet and thought it was
a way to test a racing engine after a fresh rebuild like they do every
second race or so.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
William Oliveri wrote:
>
> Offical Complete results of the Leak down test with the proper fitting is as
> follows:
>
> #1 -- 14.4%
> #2 -- 24.5%
> #3 -- 17.7%
> #4 -- 11.1%
> #5 -- 10.0%
> #6 -- 13.3%
>
> Just for the record.
#17
Guest
Posts: n/a
Re: Leak Down test results
Mike,
It is most common for racers to use leakdown to test the condition of their
engine, but there is much more you can diagnose with it. An engine can show
relatively good compression numbers and still have a problem, but not
necessarily all the time. For instance, a head gasket that has started to
seep (and will fail eventually) doesn't always get detected with a
compression test due to the short time the cylinder sees pressure while
cranking the engine. A leakdown test will find that seeping gasket if the
air is left on long enough. I have also detected a bad exhaust valve with a
leakdown that wasn't detected with a compression test. This particular
engine ran fine, except for an very infrequent pop out the exhaust pipe. The
leakdown showed it was only holding 40% as compared to 80-85 for the other
cylinders. When we tore the heads off, there was an exhaust valve with a
small crack from the stem out to the valve seat. I would bet that eventually
this valve would have broke and caused some serious damage. It was on a
Dodge 440 that got driven pretty hard.
After looking at the numbers Bill got, and thinking about it a bit, he
"might" have a problem with one of the rings on that piston. I wouldn't
diagnose it as this until all the of other possibilities are checked. I
didn't want to scare him by posting this, and I think you were also right in
saying that he should check the injector for that cylinder before he tears
into the engine. Without any of us actually seeing his plug coloring, it is
hard to diagnose the problem. It may not be oil on the plug, or the oil may
be getting there because the extra gas is washing the cylinder down which
will not let the oil control ring work like it should. I hope for his sake
it is something like a bad injector, and because he bought his EFI kit used,
there is a good possibility of that.
Chris
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:402BBEB4.D3763E0D@sympatico.ca...
> Ok, I am curious...
>
> Do you have any idea just what those numbers represent or mean? I
> really don't.
>
> I am taking a wild assed guess and am thinking those represent the shape
> of the valve seats. You did say you had some play in the valve stems on
> #2 right? This will make a strange oval wear pattern on the valve
> seating area.
>
> I mean the compression is way up there like a new engine, so things like
> rings and gaskets are fine. The book says a new 258 should have 140-150
> psi compression, but most important is even compression.
>
> Your compression is 'perfect'.
>
> It must be the seats of the metal parts that the leak down test
> tests???
>
> I honestly have never seen or heard of in person anyone doing that kind
> of test. I have only heard about it on the internet and thought it was
> a way to test a racing engine after a fresh rebuild like they do every
> second race or so.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
> >
> > Offical Complete results of the Leak down test with the proper fitting
is as
> > follows:
> >
> > #1 -- 14.4%
> > #2 -- 24.5%
> > #3 -- 17.7%
> > #4 -- 11.1%
> > #5 -- 10.0%
> > #6 -- 13.3%
> >
> > Just for the record.
It is most common for racers to use leakdown to test the condition of their
engine, but there is much more you can diagnose with it. An engine can show
relatively good compression numbers and still have a problem, but not
necessarily all the time. For instance, a head gasket that has started to
seep (and will fail eventually) doesn't always get detected with a
compression test due to the short time the cylinder sees pressure while
cranking the engine. A leakdown test will find that seeping gasket if the
air is left on long enough. I have also detected a bad exhaust valve with a
leakdown that wasn't detected with a compression test. This particular
engine ran fine, except for an very infrequent pop out the exhaust pipe. The
leakdown showed it was only holding 40% as compared to 80-85 for the other
cylinders. When we tore the heads off, there was an exhaust valve with a
small crack from the stem out to the valve seat. I would bet that eventually
this valve would have broke and caused some serious damage. It was on a
Dodge 440 that got driven pretty hard.
After looking at the numbers Bill got, and thinking about it a bit, he
"might" have a problem with one of the rings on that piston. I wouldn't
diagnose it as this until all the of other possibilities are checked. I
didn't want to scare him by posting this, and I think you were also right in
saying that he should check the injector for that cylinder before he tears
into the engine. Without any of us actually seeing his plug coloring, it is
hard to diagnose the problem. It may not be oil on the plug, or the oil may
be getting there because the extra gas is washing the cylinder down which
will not let the oil control ring work like it should. I hope for his sake
it is something like a bad injector, and because he bought his EFI kit used,
there is a good possibility of that.
Chris
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:402BBEB4.D3763E0D@sympatico.ca...
> Ok, I am curious...
>
> Do you have any idea just what those numbers represent or mean? I
> really don't.
>
> I am taking a wild assed guess and am thinking those represent the shape
> of the valve seats. You did say you had some play in the valve stems on
> #2 right? This will make a strange oval wear pattern on the valve
> seating area.
>
> I mean the compression is way up there like a new engine, so things like
> rings and gaskets are fine. The book says a new 258 should have 140-150
> psi compression, but most important is even compression.
>
> Your compression is 'perfect'.
>
> It must be the seats of the metal parts that the leak down test
> tests???
>
> I honestly have never seen or heard of in person anyone doing that kind
> of test. I have only heard about it on the internet and thought it was
> a way to test a racing engine after a fresh rebuild like they do every
> second race or so.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
> >
> > Offical Complete results of the Leak down test with the proper fitting
is as
> > follows:
> >
> > #1 -- 14.4%
> > #2 -- 24.5%
> > #3 -- 17.7%
> > #4 -- 11.1%
> > #5 -- 10.0%
> > #6 -- 13.3%
> >
> > Just for the record.
#18
Guest
Posts: n/a
Re: Leak Down test results
Mike,
It is most common for racers to use leakdown to test the condition of their
engine, but there is much more you can diagnose with it. An engine can show
relatively good compression numbers and still have a problem, but not
necessarily all the time. For instance, a head gasket that has started to
seep (and will fail eventually) doesn't always get detected with a
compression test due to the short time the cylinder sees pressure while
cranking the engine. A leakdown test will find that seeping gasket if the
air is left on long enough. I have also detected a bad exhaust valve with a
leakdown that wasn't detected with a compression test. This particular
engine ran fine, except for an very infrequent pop out the exhaust pipe. The
leakdown showed it was only holding 40% as compared to 80-85 for the other
cylinders. When we tore the heads off, there was an exhaust valve with a
small crack from the stem out to the valve seat. I would bet that eventually
this valve would have broke and caused some serious damage. It was on a
Dodge 440 that got driven pretty hard.
After looking at the numbers Bill got, and thinking about it a bit, he
"might" have a problem with one of the rings on that piston. I wouldn't
diagnose it as this until all the of other possibilities are checked. I
didn't want to scare him by posting this, and I think you were also right in
saying that he should check the injector for that cylinder before he tears
into the engine. Without any of us actually seeing his plug coloring, it is
hard to diagnose the problem. It may not be oil on the plug, or the oil may
be getting there because the extra gas is washing the cylinder down which
will not let the oil control ring work like it should. I hope for his sake
it is something like a bad injector, and because he bought his EFI kit used,
there is a good possibility of that.
Chris
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:402BBEB4.D3763E0D@sympatico.ca...
> Ok, I am curious...
>
> Do you have any idea just what those numbers represent or mean? I
> really don't.
>
> I am taking a wild assed guess and am thinking those represent the shape
> of the valve seats. You did say you had some play in the valve stems on
> #2 right? This will make a strange oval wear pattern on the valve
> seating area.
>
> I mean the compression is way up there like a new engine, so things like
> rings and gaskets are fine. The book says a new 258 should have 140-150
> psi compression, but most important is even compression.
>
> Your compression is 'perfect'.
>
> It must be the seats of the metal parts that the leak down test
> tests???
>
> I honestly have never seen or heard of in person anyone doing that kind
> of test. I have only heard about it on the internet and thought it was
> a way to test a racing engine after a fresh rebuild like they do every
> second race or so.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
> >
> > Offical Complete results of the Leak down test with the proper fitting
is as
> > follows:
> >
> > #1 -- 14.4%
> > #2 -- 24.5%
> > #3 -- 17.7%
> > #4 -- 11.1%
> > #5 -- 10.0%
> > #6 -- 13.3%
> >
> > Just for the record.
It is most common for racers to use leakdown to test the condition of their
engine, but there is much more you can diagnose with it. An engine can show
relatively good compression numbers and still have a problem, but not
necessarily all the time. For instance, a head gasket that has started to
seep (and will fail eventually) doesn't always get detected with a
compression test due to the short time the cylinder sees pressure while
cranking the engine. A leakdown test will find that seeping gasket if the
air is left on long enough. I have also detected a bad exhaust valve with a
leakdown that wasn't detected with a compression test. This particular
engine ran fine, except for an very infrequent pop out the exhaust pipe. The
leakdown showed it was only holding 40% as compared to 80-85 for the other
cylinders. When we tore the heads off, there was an exhaust valve with a
small crack from the stem out to the valve seat. I would bet that eventually
this valve would have broke and caused some serious damage. It was on a
Dodge 440 that got driven pretty hard.
After looking at the numbers Bill got, and thinking about it a bit, he
"might" have a problem with one of the rings on that piston. I wouldn't
diagnose it as this until all the of other possibilities are checked. I
didn't want to scare him by posting this, and I think you were also right in
saying that he should check the injector for that cylinder before he tears
into the engine. Without any of us actually seeing his plug coloring, it is
hard to diagnose the problem. It may not be oil on the plug, or the oil may
be getting there because the extra gas is washing the cylinder down which
will not let the oil control ring work like it should. I hope for his sake
it is something like a bad injector, and because he bought his EFI kit used,
there is a good possibility of that.
Chris
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:402BBEB4.D3763E0D@sympatico.ca...
> Ok, I am curious...
>
> Do you have any idea just what those numbers represent or mean? I
> really don't.
>
> I am taking a wild assed guess and am thinking those represent the shape
> of the valve seats. You did say you had some play in the valve stems on
> #2 right? This will make a strange oval wear pattern on the valve
> seating area.
>
> I mean the compression is way up there like a new engine, so things like
> rings and gaskets are fine. The book says a new 258 should have 140-150
> psi compression, but most important is even compression.
>
> Your compression is 'perfect'.
>
> It must be the seats of the metal parts that the leak down test
> tests???
>
> I honestly have never seen or heard of in person anyone doing that kind
> of test. I have only heard about it on the internet and thought it was
> a way to test a racing engine after a fresh rebuild like they do every
> second race or so.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
> >
> > Offical Complete results of the Leak down test with the proper fitting
is as
> > follows:
> >
> > #1 -- 14.4%
> > #2 -- 24.5%
> > #3 -- 17.7%
> > #4 -- 11.1%
> > #5 -- 10.0%
> > #6 -- 13.3%
> >
> > Just for the record.
#19
Guest
Posts: n/a
Re: Leak Down test results
Mike,
It is most common for racers to use leakdown to test the condition of their
engine, but there is much more you can diagnose with it. An engine can show
relatively good compression numbers and still have a problem, but not
necessarily all the time. For instance, a head gasket that has started to
seep (and will fail eventually) doesn't always get detected with a
compression test due to the short time the cylinder sees pressure while
cranking the engine. A leakdown test will find that seeping gasket if the
air is left on long enough. I have also detected a bad exhaust valve with a
leakdown that wasn't detected with a compression test. This particular
engine ran fine, except for an very infrequent pop out the exhaust pipe. The
leakdown showed it was only holding 40% as compared to 80-85 for the other
cylinders. When we tore the heads off, there was an exhaust valve with a
small crack from the stem out to the valve seat. I would bet that eventually
this valve would have broke and caused some serious damage. It was on a
Dodge 440 that got driven pretty hard.
After looking at the numbers Bill got, and thinking about it a bit, he
"might" have a problem with one of the rings on that piston. I wouldn't
diagnose it as this until all the of other possibilities are checked. I
didn't want to scare him by posting this, and I think you were also right in
saying that he should check the injector for that cylinder before he tears
into the engine. Without any of us actually seeing his plug coloring, it is
hard to diagnose the problem. It may not be oil on the plug, or the oil may
be getting there because the extra gas is washing the cylinder down which
will not let the oil control ring work like it should. I hope for his sake
it is something like a bad injector, and because he bought his EFI kit used,
there is a good possibility of that.
Chris
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:402BBEB4.D3763E0D@sympatico.ca...
> Ok, I am curious...
>
> Do you have any idea just what those numbers represent or mean? I
> really don't.
>
> I am taking a wild assed guess and am thinking those represent the shape
> of the valve seats. You did say you had some play in the valve stems on
> #2 right? This will make a strange oval wear pattern on the valve
> seating area.
>
> I mean the compression is way up there like a new engine, so things like
> rings and gaskets are fine. The book says a new 258 should have 140-150
> psi compression, but most important is even compression.
>
> Your compression is 'perfect'.
>
> It must be the seats of the metal parts that the leak down test
> tests???
>
> I honestly have never seen or heard of in person anyone doing that kind
> of test. I have only heard about it on the internet and thought it was
> a way to test a racing engine after a fresh rebuild like they do every
> second race or so.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
> >
> > Offical Complete results of the Leak down test with the proper fitting
is as
> > follows:
> >
> > #1 -- 14.4%
> > #2 -- 24.5%
> > #3 -- 17.7%
> > #4 -- 11.1%
> > #5 -- 10.0%
> > #6 -- 13.3%
> >
> > Just for the record.
It is most common for racers to use leakdown to test the condition of their
engine, but there is much more you can diagnose with it. An engine can show
relatively good compression numbers and still have a problem, but not
necessarily all the time. For instance, a head gasket that has started to
seep (and will fail eventually) doesn't always get detected with a
compression test due to the short time the cylinder sees pressure while
cranking the engine. A leakdown test will find that seeping gasket if the
air is left on long enough. I have also detected a bad exhaust valve with a
leakdown that wasn't detected with a compression test. This particular
engine ran fine, except for an very infrequent pop out the exhaust pipe. The
leakdown showed it was only holding 40% as compared to 80-85 for the other
cylinders. When we tore the heads off, there was an exhaust valve with a
small crack from the stem out to the valve seat. I would bet that eventually
this valve would have broke and caused some serious damage. It was on a
Dodge 440 that got driven pretty hard.
After looking at the numbers Bill got, and thinking about it a bit, he
"might" have a problem with one of the rings on that piston. I wouldn't
diagnose it as this until all the of other possibilities are checked. I
didn't want to scare him by posting this, and I think you were also right in
saying that he should check the injector for that cylinder before he tears
into the engine. Without any of us actually seeing his plug coloring, it is
hard to diagnose the problem. It may not be oil on the plug, or the oil may
be getting there because the extra gas is washing the cylinder down which
will not let the oil control ring work like it should. I hope for his sake
it is something like a bad injector, and because he bought his EFI kit used,
there is a good possibility of that.
Chris
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:402BBEB4.D3763E0D@sympatico.ca...
> Ok, I am curious...
>
> Do you have any idea just what those numbers represent or mean? I
> really don't.
>
> I am taking a wild assed guess and am thinking those represent the shape
> of the valve seats. You did say you had some play in the valve stems on
> #2 right? This will make a strange oval wear pattern on the valve
> seating area.
>
> I mean the compression is way up there like a new engine, so things like
> rings and gaskets are fine. The book says a new 258 should have 140-150
> psi compression, but most important is even compression.
>
> Your compression is 'perfect'.
>
> It must be the seats of the metal parts that the leak down test
> tests???
>
> I honestly have never seen or heard of in person anyone doing that kind
> of test. I have only heard about it on the internet and thought it was
> a way to test a racing engine after a fresh rebuild like they do every
> second race or so.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
> >
> > Offical Complete results of the Leak down test with the proper fitting
is as
> > follows:
> >
> > #1 -- 14.4%
> > #2 -- 24.5%
> > #3 -- 17.7%
> > #4 -- 11.1%
> > #5 -- 10.0%
> > #6 -- 13.3%
> >
> > Just for the record.
#20
Guest
Posts: n/a
Re: Leak Down test results
Chris,
Thank you for your reply. You won't scare me as I am not mentally ready
for the worse but hoping for the best.
Thanks,
"c" <c@me.org> wrote in message
news:GCQWb.5218$_66.4336@twister.rdc-kc.rr.com...
> Mike,
>
> It is most common for racers to use leakdown to test the condition of
their
> engine, but there is much more you can diagnose with it. An engine can
show
> relatively good compression numbers and still have a problem, but not
> necessarily all the time. For instance, a head gasket that has started to
> seep (and will fail eventually) doesn't always get detected with a
> compression test due to the short time the cylinder sees pressure while
> cranking the engine. A leakdown test will find that seeping gasket if the
> air is left on long enough. I have also detected a bad exhaust valve with
a
> leakdown that wasn't detected with a compression test. This particular
> engine ran fine, except for an very infrequent pop out the exhaust pipe.
The
> leakdown showed it was only holding 40% as compared to 80-85 for the other
> cylinders. When we tore the heads off, there was an exhaust valve with a
> small crack from the stem out to the valve seat. I would bet that
eventually
> this valve would have broke and caused some serious damage. It was on a
> Dodge 440 that got driven pretty hard.
>
> After looking at the numbers Bill got, and thinking about it a bit, he
> "might" have a problem with one of the rings on that piston. I wouldn't
> diagnose it as this until all the of other possibilities are checked. I
> didn't want to scare him by posting this, and I think you were also right
in
> saying that he should check the injector for that cylinder before he tears
> into the engine. Without any of us actually seeing his plug coloring, it
is
> hard to diagnose the problem. It may not be oil on the plug, or the oil
may
> be getting there because the extra gas is washing the cylinder down which
> will not let the oil control ring work like it should. I hope for his sake
> it is something like a bad injector, and because he bought his EFI kit
used,
> there is a good possibility of that.
>
> Chris
>
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:402BBEB4.D3763E0D@sympatico.ca...
> > Ok, I am curious...
> >
> > Do you have any idea just what those numbers represent or mean? I
> > really don't.
> >
> > I am taking a wild assed guess and am thinking those represent the shape
> > of the valve seats. You did say you had some play in the valve stems on
> > #2 right? This will make a strange oval wear pattern on the valve
> > seating area.
> >
> > I mean the compression is way up there like a new engine, so things like
> > rings and gaskets are fine. The book says a new 258 should have 140-150
> > psi compression, but most important is even compression.
> >
> > Your compression is 'perfect'.
> >
> > It must be the seats of the metal parts that the leak down test
> > tests???
> >
> > I honestly have never seen or heard of in person anyone doing that kind
> > of test. I have only heard about it on the internet and thought it was
> > a way to test a racing engine after a fresh rebuild like they do every
> > second race or so.
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> >
> > William Oliveri wrote:
> > >
> > > Offical Complete results of the Leak down test with the proper fitting
> is as
> > > follows:
> > >
> > > #1 -- 14.4%
> > > #2 -- 24.5%
> > > #3 -- 17.7%
> > > #4 -- 11.1%
> > > #5 -- 10.0%
> > > #6 -- 13.3%
> > >
> > > Just for the record.
>
>
Thank you for your reply. You won't scare me as I am not mentally ready
for the worse but hoping for the best.
Thanks,
"c" <c@me.org> wrote in message
news:GCQWb.5218$_66.4336@twister.rdc-kc.rr.com...
> Mike,
>
> It is most common for racers to use leakdown to test the condition of
their
> engine, but there is much more you can diagnose with it. An engine can
show
> relatively good compression numbers and still have a problem, but not
> necessarily all the time. For instance, a head gasket that has started to
> seep (and will fail eventually) doesn't always get detected with a
> compression test due to the short time the cylinder sees pressure while
> cranking the engine. A leakdown test will find that seeping gasket if the
> air is left on long enough. I have also detected a bad exhaust valve with
a
> leakdown that wasn't detected with a compression test. This particular
> engine ran fine, except for an very infrequent pop out the exhaust pipe.
The
> leakdown showed it was only holding 40% as compared to 80-85 for the other
> cylinders. When we tore the heads off, there was an exhaust valve with a
> small crack from the stem out to the valve seat. I would bet that
eventually
> this valve would have broke and caused some serious damage. It was on a
> Dodge 440 that got driven pretty hard.
>
> After looking at the numbers Bill got, and thinking about it a bit, he
> "might" have a problem with one of the rings on that piston. I wouldn't
> diagnose it as this until all the of other possibilities are checked. I
> didn't want to scare him by posting this, and I think you were also right
in
> saying that he should check the injector for that cylinder before he tears
> into the engine. Without any of us actually seeing his plug coloring, it
is
> hard to diagnose the problem. It may not be oil on the plug, or the oil
may
> be getting there because the extra gas is washing the cylinder down which
> will not let the oil control ring work like it should. I hope for his sake
> it is something like a bad injector, and because he bought his EFI kit
used,
> there is a good possibility of that.
>
> Chris
>
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:402BBEB4.D3763E0D@sympatico.ca...
> > Ok, I am curious...
> >
> > Do you have any idea just what those numbers represent or mean? I
> > really don't.
> >
> > I am taking a wild assed guess and am thinking those represent the shape
> > of the valve seats. You did say you had some play in the valve stems on
> > #2 right? This will make a strange oval wear pattern on the valve
> > seating area.
> >
> > I mean the compression is way up there like a new engine, so things like
> > rings and gaskets are fine. The book says a new 258 should have 140-150
> > psi compression, but most important is even compression.
> >
> > Your compression is 'perfect'.
> >
> > It must be the seats of the metal parts that the leak down test
> > tests???
> >
> > I honestly have never seen or heard of in person anyone doing that kind
> > of test. I have only heard about it on the internet and thought it was
> > a way to test a racing engine after a fresh rebuild like they do every
> > second race or so.
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> >
> > William Oliveri wrote:
> > >
> > > Offical Complete results of the Leak down test with the proper fitting
> is as
> > > follows:
> > >
> > > #1 -- 14.4%
> > > #2 -- 24.5%
> > > #3 -- 17.7%
> > > #4 -- 11.1%
> > > #5 -- 10.0%
> > > #6 -- 13.3%
> > >
> > > Just for the record.
>
>