Re: Overheating CJ7, the story so far
 

On top of what others have posted, you may want to disconnect the lines to
the heater core and flush in both directions. Don't let that crap from the
heater core into your engine, radiator, etc...

I did this when I pulled my engine, and, even though I had flushed the
cooling system recently, I was surprised at the amount of crap that came
out.
--
Michael White "To protect people from the effects of folly is to
fill the world with fools." -Herbert Spencer, 1891

David Harmon (source@netcom.com) wrote on Saturday 08 May 2004 07:08 pm:

> Friday, April 30
> On trip to Irvine, it became apparent to me that my Jeep engine was
> overheating too much to ignore.
>
> My temperature gauge has been dead for years, because of a failed
> voltage regulator in the fuel gauge that supplies both of them.
> http://www.monsterslayer.com/jeep/Gauges.htm
>
> Tuesday, May 4.
> Whereas I already had a spare thermostat ready to go, that became the
> first thing to attack. Before starting, checked the new thermostat in a
> pot of boiling water on the stove; it opens as expected. Pulled old
> thermostat, put in new one. Jeep still overheats. Old thermostat in
> pot on stove acts just like the new one.
>
> Wednesday, May 5.
> Went to Pep Boys, bought a bunch of stuff. A nice mechanical water temp
> gauge. Prestone flush kit, consisting of tee fitting that goes in the
> heater hose for hooking up to garden hose, and a cheesy tube to divert
> the overflow a couple of inches away in a chosen direction. Bottle of
> flush chemical, label says it has sodium citrate in it. Bottle of water
> pump lubricant and three bottles of antifreeze. Cheesy Prestone
> hydrometer.
>
> Installed the temp gauge in a fitting in the water passages in the
> intake manifold that, for some odd reason, I believed was where it was
> supposed to go. Readings very squirrely.
>
> Modified the Prestone overflow tube by adding a hose fitting, so with a
> second garden hose I can route the overflow someplace inoffensive
> instead of dumping it on my shoes.
>
> Thursday, May 6.
> Figured out that I had hooked up the new gauge wrong. The fitting on
> the manifold is the wrong place. The right place to connect it is on
> the block like God intended it. The gauge sensor is to big to fit
> there. Too bad, and it was such a great fit in the wrong place. Out it
> comes, and again I have no temperature gauge.
>
> Installed Prestone flush kit. Prestone says to put the tee in the upper
> heater hose, where it comes out of the top of the engine. Problem is,
> my heater hose connects on the radiator side of the thermostat, while
> they assume it connects on the engine side. If I connect it on top, I
> will be flushing nothing but the top radiator tank. I connect it in the
> bottom heater hose. That way, the water at least has to go through
> either the heater core or the radiator core to get out.
>
> Drained the radiator. Contents looking like swamp water, more brown
> than green. Hydrometer says there's not much antifreeze in it.
>
> Flushed with water for a while.
>
> Closed it up, added the flush chemical. Drove around the block until
> hot, then let it sit until cool. Drained.
>
> Flushed with water again. Discovered that by squeezing the heater hose
> shut with vice grip pliers I could make sure the water went both ways,
> heater and radiator. Good. Unfortunately, as the thermostat was
> closed, I suspect not much flushing happened in the block water
> passages. I guess a fair amount of rust and/or sludge has come out. but
> I don't know what to compare against. Water coming out is clear.
>
> Filled with good antifreeze and water pump lubricant. The passenger
> compartment heater, which has been almost useless for years, is now
> putting out heat, so at least I did that much good. Jeep still
> overheats.
>
> (H) relates the story of a vehicle having the same sort of problem,
> cured by replacing an old tired radiator cap with one that hold the
> proper pressure. (H) and I make a late night shopping run to Pep
> Boys for a radiator cap and the Despot for some water fittings.
>
> Friday, May 7.
> Hooked up pressure gauge to the Prestone flush port. On a test drive,
> old radiator cap blows off at 10 PSI. Installed new radiator cap.
> New radiator cap blows off at 16 PSI, matching spec. Jeep still
> overheats.
>
> (H) finally talks me in to doing the compression check, to see if I
> have a blown head gasket.
> Cyl PSI PSI (each cylinder checked twice.)
> 1 158 158
> 2 173 173
> 3 158 160
> 4 165 163
> 5 163 163
> 6 150 156
>
> We concluded no blown head gasket.
>
> Talked to (D). He believes I need more flushing of the block water
> passages. And what else is there to consider? That and the water pump.
> So, I thing the water pump has to come off for inspection at least, and
> if it's off then maybe it is a dumb idea to not put a new one on even if
> it looks good. When it is off, that would be the time to flush the
> block. I don't know yet what kind of rig up I can use to flush the
> block.

Re: Overheating CJ7, the story so far
 

Where does this crap come from? water in the system that's rusting parts?
Or oil seeping in to the coolant?


"David Harmon" <source@netcom.com> wrote in message
news:41267525.459900053@news.west.earthlink.net...
> Friday, April 30
> On trip to Irvine, it became apparent to me that my Jeep engine was
> overheating too much to ignore.
>
> My temperature gauge has been dead for years, because of a failed
> voltage regulator in the fuel gauge that supplies both of them.
> http://www.monsterslayer.com/jeep/Gauges.htm
>
> Tuesday, May 4.
> Whereas I already had a spare thermostat ready to go, that became the
> first thing to attack. Before starting, checked the new thermostat in a
> pot of boiling water on the stove; it opens as expected. Pulled old
> thermostat, put in new one. Jeep still overheats. Old thermostat in
> pot on stove acts just like the new one.
>
> Wednesday, May 5.
> Went to Pep Boys, bought a bunch of stuff. A nice mechanical water temp
> gauge. Prestone flush kit, consisting of tee fitting that goes in the
> heater hose for hooking up to garden hose, and a cheesy tube to divert
> the overflow a couple of inches away in a chosen direction. Bottle of
> flush chemical, label says it has sodium citrate in it. Bottle of water
> pump lubricant and three bottles of antifreeze. Cheesy Prestone
> hydrometer.
>
> Installed the temp gauge in a fitting in the water passages in the
> intake manifold that, for some odd reason, I believed was where it was
> supposed to go. Readings very squirrely.
>
> Modified the Prestone overflow tube by adding a hose fitting, so with a
> second garden hose I can route the overflow someplace inoffensive
> instead of dumping it on my shoes.
>
> Thursday, May 6.
> Figured out that I had hooked up the new gauge wrong. The fitting on
> the manifold is the wrong place. The right place to connect it is on
> the block like God intended it. The gauge sensor is to big to fit
> there. Too bad, and it was such a great fit in the wrong place. Out it
> comes, and again I have no temperature gauge.
>
> Installed Prestone flush kit. Prestone says to put the tee in the upper
> heater hose, where it comes out of the top of the engine. Problem is,
> my heater hose connects on the radiator side of the thermostat, while
> they assume it connects on the engine side. If I connect it on top, I
> will be flushing nothing but the top radiator tank. I connect it in the
> bottom heater hose. That way, the water at least has to go through
> either the heater core or the radiator core to get out.
>
> Drained the radiator. Contents looking like swamp water, more brown
> than green. Hydrometer says there's not much antifreeze in it.
>
> Flushed with water for a while.
>
> Closed it up, added the flush chemical. Drove around the block until
> hot, then let it sit until cool. Drained.
>
> Flushed with water again. Discovered that by squeezing the heater hose
> shut with vice grip pliers I could make sure the water went both ways,
> heater and radiator. Good. Unfortunately, as the thermostat was
> closed, I suspect not much flushing happened in the block water
> passages. I guess a fair amount of rust and/or sludge has come out. but
> I don't know what to compare against. Water coming out is clear.
>
> Filled with good antifreeze and water pump lubricant. The passenger
> compartment heater, which has been almost useless for years, is now
> putting out heat, so at least I did that much good. Jeep still
> overheats.
>
> (H) relates the story of a vehicle having the same sort of problem,
> cured by replacing an old tired radiator cap with one that hold the
> proper pressure. (H) and I make a late night shopping run to Pep
> Boys for a radiator cap and the Despot for some water fittings.
>
> Friday, May 7.
> Hooked up pressure gauge to the Prestone flush port. On a test drive,
> old radiator cap blows off at 10 PSI. Installed new radiator cap.
> New radiator cap blows off at 16 PSI, matching spec. Jeep still
> overheats.
>
> (H) finally talks me in to doing the compression check, to see if I
> have a blown head gasket.
> Cyl PSI PSI (each cylinder checked twice.)
> 1 158 158
> 2 173 173
> 3 158 160
> 4 165 163
> 5 163 163
> 6 150 156
>
> We concluded no blown head gasket.
>
> Talked to (D). He believes I need more flushing of the block water
> passages. And what else is there to consider? That and the water pump.
> So, I thing the water pump has to come off for inspection at least, and
> if it's off then maybe it is a dumb idea to not put a new one on even if
> it looks good. When it is off, that would be the time to flush the
> block. I don't know yet what kind of rig up I can use to flush the
> block.
>

Re: Overheating CJ7, the story so far
 

Where does this crap come from? water in the system that's rusting parts?
Or oil seeping in to the coolant?


"David Harmon" <source@netcom.com> wrote in message
news:41267525.459900053@news.west.earthlink.net...
> Friday, April 30
> On trip to Irvine, it became apparent to me that my Jeep engine was
> overheating too much to ignore.
>
> My temperature gauge has been dead for years, because of a failed
> voltage regulator in the fuel gauge that supplies both of them.
> http://www.monsterslayer.com/jeep/Gauges.htm
>
> Tuesday, May 4.
> Whereas I already had a spare thermostat ready to go, that became the
> first thing to attack. Before starting, checked the new thermostat in a
> pot of boiling water on the stove; it opens as expected. Pulled old
> thermostat, put in new one. Jeep still overheats. Old thermostat in
> pot on stove acts just like the new one.
>
> Wednesday, May 5.
> Went to Pep Boys, bought a bunch of stuff. A nice mechanical water temp
> gauge. Prestone flush kit, consisting of tee fitting that goes in the
> heater hose for hooking up to garden hose, and a cheesy tube to divert
> the overflow a couple of inches away in a chosen direction. Bottle of
> flush chemical, label says it has sodium citrate in it. Bottle of water
> pump lubricant and three bottles of antifreeze. Cheesy Prestone
> hydrometer.
>
> Installed the temp gauge in a fitting in the water passages in the
> intake manifold that, for some odd reason, I believed was where it was
> supposed to go. Readings very squirrely.
>
> Modified the Prestone overflow tube by adding a hose fitting, so with a
> second garden hose I can route the overflow someplace inoffensive
> instead of dumping it on my shoes.
>
> Thursday, May 6.
> Figured out that I had hooked up the new gauge wrong. The fitting on
> the manifold is the wrong place. The right place to connect it is on
> the block like God intended it. The gauge sensor is to big to fit
> there. Too bad, and it was such a great fit in the wrong place. Out it
> comes, and again I have no temperature gauge.
>
> Installed Prestone flush kit. Prestone says to put the tee in the upper
> heater hose, where it comes out of the top of the engine. Problem is,
> my heater hose connects on the radiator side of the thermostat, while
> they assume it connects on the engine side. If I connect it on top, I
> will be flushing nothing but the top radiator tank. I connect it in the
> bottom heater hose. That way, the water at least has to go through
> either the heater core or the radiator core to get out.
>
> Drained the radiator. Contents looking like swamp water, more brown
> than green. Hydrometer says there's not much antifreeze in it.
>
> Flushed with water for a while.
>
> Closed it up, added the flush chemical. Drove around the block until
> hot, then let it sit until cool. Drained.
>
> Flushed with water again. Discovered that by squeezing the heater hose
> shut with vice grip pliers I could make sure the water went both ways,
> heater and radiator. Good. Unfortunately, as the thermostat was
> closed, I suspect not much flushing happened in the block water
> passages. I guess a fair amount of rust and/or sludge has come out. but
> I don't know what to compare against. Water coming out is clear.
>
> Filled with good antifreeze and water pump lubricant. The passenger
> compartment heater, which has been almost useless for years, is now
> putting out heat, so at least I did that much good. Jeep still
> overheats.
>
> (H) relates the story of a vehicle having the same sort of problem,
> cured by replacing an old tired radiator cap with one that hold the
> proper pressure. (H) and I make a late night shopping run to Pep
> Boys for a radiator cap and the Despot for some water fittings.
>
> Friday, May 7.
> Hooked up pressure gauge to the Prestone flush port. On a test drive,
> old radiator cap blows off at 10 PSI. Installed new radiator cap.
> New radiator cap blows off at 16 PSI, matching spec. Jeep still
> overheats.
>
> (H) finally talks me in to doing the compression check, to see if I
> have a blown head gasket.
> Cyl PSI PSI (each cylinder checked twice.)
> 1 158 158
> 2 173 173
> 3 158 160
> 4 165 163
> 5 163 163
> 6 150 156
>
> We concluded no blown head gasket.
>
> Talked to (D). He believes I need more flushing of the block water
> passages. And what else is there to consider? That and the water pump.
> So, I thing the water pump has to come off for inspection at least, and
> if it's off then maybe it is a dumb idea to not put a new one on even if
> it looks good. When it is off, that would be the time to flush the
> block. I don't know yet what kind of rig up I can use to flush the
> block.
>

Re: Overheating CJ7, the story so far
 

Where does this crap come from? water in the system that's rusting parts?
Or oil seeping in to the coolant?


"David Harmon" <source@netcom.com> wrote in message
news:41267525.459900053@news.west.earthlink.net...
> Friday, April 30
> On trip to Irvine, it became apparent to me that my Jeep engine was
> overheating too much to ignore.
>
> My temperature gauge has been dead for years, because of a failed
> voltage regulator in the fuel gauge that supplies both of them.
> http://www.monsterslayer.com/jeep/Gauges.htm
>
> Tuesday, May 4.
> Whereas I already had a spare thermostat ready to go, that became the
> first thing to attack. Before starting, checked the new thermostat in a
> pot of boiling water on the stove; it opens as expected. Pulled old
> thermostat, put in new one. Jeep still overheats. Old thermostat in
> pot on stove acts just like the new one.
>
> Wednesday, May 5.
> Went to Pep Boys, bought a bunch of stuff. A nice mechanical water temp
> gauge. Prestone flush kit, consisting of tee fitting that goes in the
> heater hose for hooking up to garden hose, and a cheesy tube to divert
> the overflow a couple of inches away in a chosen direction. Bottle of
> flush chemical, label says it has sodium citrate in it. Bottle of water
> pump lubricant and three bottles of antifreeze. Cheesy Prestone
> hydrometer.
>
> Installed the temp gauge in a fitting in the water passages in the
> intake manifold that, for some odd reason, I believed was where it was
> supposed to go. Readings very squirrely.
>
> Modified the Prestone overflow tube by adding a hose fitting, so with a
> second garden hose I can route the overflow someplace inoffensive
> instead of dumping it on my shoes.
>
> Thursday, May 6.
> Figured out that I had hooked up the new gauge wrong. The fitting on
> the manifold is the wrong place. The right place to connect it is on
> the block like God intended it. The gauge sensor is to big to fit
> there. Too bad, and it was such a great fit in the wrong place. Out it
> comes, and again I have no temperature gauge.
>
> Installed Prestone flush kit. Prestone says to put the tee in the upper
> heater hose, where it comes out of the top of the engine. Problem is,
> my heater hose connects on the radiator side of the thermostat, while
> they assume it connects on the engine side. If I connect it on top, I
> will be flushing nothing but the top radiator tank. I connect it in the
> bottom heater hose. That way, the water at least has to go through
> either the heater core or the radiator core to get out.
>
> Drained the radiator. Contents looking like swamp water, more brown
> than green. Hydrometer says there's not much antifreeze in it.
>
> Flushed with water for a while.
>
> Closed it up, added the flush chemical. Drove around the block until
> hot, then let it sit until cool. Drained.
>
> Flushed with water again. Discovered that by squeezing the heater hose
> shut with vice grip pliers I could make sure the water went both ways,
> heater and radiator. Good. Unfortunately, as the thermostat was
> closed, I suspect not much flushing happened in the block water
> passages. I guess a fair amount of rust and/or sludge has come out. but
> I don't know what to compare against. Water coming out is clear.
>
> Filled with good antifreeze and water pump lubricant. The passenger
> compartment heater, which has been almost useless for years, is now
> putting out heat, so at least I did that much good. Jeep still
> overheats.
>
> (H) relates the story of a vehicle having the same sort of problem,
> cured by replacing an old tired radiator cap with one that hold the
> proper pressure. (H) and I make a late night shopping run to Pep
> Boys for a radiator cap and the Despot for some water fittings.
>
> Friday, May 7.
> Hooked up pressure gauge to the Prestone flush port. On a test drive,
> old radiator cap blows off at 10 PSI. Installed new radiator cap.
> New radiator cap blows off at 16 PSI, matching spec. Jeep still
> overheats.
>
> (H) finally talks me in to doing the compression check, to see if I
> have a blown head gasket.
> Cyl PSI PSI (each cylinder checked twice.)
> 1 158 158
> 2 173 173
> 3 158 160
> 4 165 163
> 5 163 163
> 6 150 156
>
> We concluded no blown head gasket.
>
> Talked to (D). He believes I need more flushing of the block water
> passages. And what else is there to consider? That and the water pump.
> So, I thing the water pump has to come off for inspection at least, and
> if it's off then maybe it is a dumb idea to not put a new one on even if
> it looks good. When it is off, that would be the time to flush the
> block. I don't know yet what kind of rig up I can use to flush the
> block.
>

Re: Overheating CJ7, the story so far
 

Where does this crap come from? water in the system that's rusting parts?
Or oil seeping in to the coolant?


"David Harmon" <source@netcom.com> wrote in message
news:41267525.459900053@news.west.earthlink.net...
> Friday, April 30
> On trip to Irvine, it became apparent to me that my Jeep engine was
> overheating too much to ignore.
>
> My temperature gauge has been dead for years, because of a failed
> voltage regulator in the fuel gauge that supplies both of them.
> http://www.monsterslayer.com/jeep/Gauges.htm
>
> Tuesday, May 4.
> Whereas I already had a spare thermostat ready to go, that became the
> first thing to attack. Before starting, checked the new thermostat in a
> pot of boiling water on the stove; it opens as expected. Pulled old
> thermostat, put in new one. Jeep still overheats. Old thermostat in
> pot on stove acts just like the new one.
>
> Wednesday, May 5.
> Went to Pep Boys, bought a bunch of stuff. A nice mechanical water temp
> gauge. Prestone flush kit, consisting of tee fitting that goes in the
> heater hose for hooking up to garden hose, and a cheesy tube to divert
> the overflow a couple of inches away in a chosen direction. Bottle of
> flush chemical, label says it has sodium citrate in it. Bottle of water
> pump lubricant and three bottles of antifreeze. Cheesy Prestone
> hydrometer.
>
> Installed the temp gauge in a fitting in the water passages in the
> intake manifold that, for some odd reason, I believed was where it was
> supposed to go. Readings very squirrely.
>
> Modified the Prestone overflow tube by adding a hose fitting, so with a
> second garden hose I can route the overflow someplace inoffensive
> instead of dumping it on my shoes.
>
> Thursday, May 6.
> Figured out that I had hooked up the new gauge wrong. The fitting on
> the manifold is the wrong place. The right place to connect it is on
> the block like God intended it. The gauge sensor is to big to fit
> there. Too bad, and it was such a great fit in the wrong place. Out it
> comes, and again I have no temperature gauge.
>
> Installed Prestone flush kit. Prestone says to put the tee in the upper
> heater hose, where it comes out of the top of the engine. Problem is,
> my heater hose connects on the radiator side of the thermostat, while
> they assume it connects on the engine side. If I connect it on top, I
> will be flushing nothing but the top radiator tank. I connect it in the
> bottom heater hose. That way, the water at least has to go through
> either the heater core or the radiator core to get out.
>
> Drained the radiator. Contents looking like swamp water, more brown
> than green. Hydrometer says there's not much antifreeze in it.
>
> Flushed with water for a while.
>
> Closed it up, added the flush chemical. Drove around the block until
> hot, then let it sit until cool. Drained.
>
> Flushed with water again. Discovered that by squeezing the heater hose
> shut with vice grip pliers I could make sure the water went both ways,
> heater and radiator. Good. Unfortunately, as the thermostat was
> closed, I suspect not much flushing happened in the block water
> passages. I guess a fair amount of rust and/or sludge has come out. but
> I don't know what to compare against. Water coming out is clear.
>
> Filled with good antifreeze and water pump lubricant. The passenger
> compartment heater, which has been almost useless for years, is now
> putting out heat, so at least I did that much good. Jeep still
> overheats.
>
> (H) relates the story of a vehicle having the same sort of problem,
> cured by replacing an old tired radiator cap with one that hold the
> proper pressure. (H) and I make a late night shopping run to Pep
> Boys for a radiator cap and the Despot for some water fittings.
>
> Friday, May 7.
> Hooked up pressure gauge to the Prestone flush port. On a test drive,
> old radiator cap blows off at 10 PSI. Installed new radiator cap.
> New radiator cap blows off at 16 PSI, matching spec. Jeep still
> overheats.
>
> (H) finally talks me in to doing the compression check, to see if I
> have a blown head gasket.
> Cyl PSI PSI (each cylinder checked twice.)
> 1 158 158
> 2 173 173
> 3 158 160
> 4 165 163
> 5 163 163
> 6 150 156
>
> We concluded no blown head gasket.
>
> Talked to (D). He believes I need more flushing of the block water
> passages. And what else is there to consider? That and the water pump.
> So, I thing the water pump has to come off for inspection at least, and
> if it's off then maybe it is a dumb idea to not put a new one on even if
> it looks good. When it is off, that would be the time to flush the
> block. I don't know yet what kind of rig up I can use to flush the
> block.
>

Re: Overheating CJ7, the story so far
 

SB did pass the time by typing:
> Where does this crap come from? water in the system that's rusting parts?
> Or oil seeping in to the coolant?

not usually oil, that's a blown head gasket. It comes from having a poor PH
balance in the coolant or excess minerals in the water used to fill the system.
Long term it comes from corrosion of the sacrificial anode then the radiator
and block.

Another source is that leak-stop stuff. Oh, it works in a pinch (on small
leaks/seeps) but I've seen radiators with at least a pint of the stuff settled
in the bottom.

If your in an area with high mineral content or acidic water you would be better
off using the 50/50 mix sold in stores or using distilled water for filling the
radiator.

--
DougW

Re: Overheating CJ7, the story so far
 

SB did pass the time by typing:
> Where does this crap come from? water in the system that's rusting parts?
> Or oil seeping in to the coolant?

not usually oil, that's a blown head gasket. It comes from having a poor PH
balance in the coolant or excess minerals in the water used to fill the system.
Long term it comes from corrosion of the sacrificial anode then the radiator
and block.

Another source is that leak-stop stuff. Oh, it works in a pinch (on small
leaks/seeps) but I've seen radiators with at least a pint of the stuff settled
in the bottom.

If your in an area with high mineral content or acidic water you would be better
off using the 50/50 mix sold in stores or using distilled water for filling the
radiator.

--
DougW

Re: Overheating CJ7, the story so far
 

SB did pass the time by typing:
> Where does this crap come from? water in the system that's rusting parts?
> Or oil seeping in to the coolant?

not usually oil, that's a blown head gasket. It comes from having a poor PH
balance in the coolant or excess minerals in the water used to fill the system.
Long term it comes from corrosion of the sacrificial anode then the radiator
and block.

Another source is that leak-stop stuff. Oh, it works in a pinch (on small
leaks/seeps) but I've seen radiators with at least a pint of the stuff settled
in the bottom.

If your in an area with high mineral content or acidic water you would be better
off using the 50/50 mix sold in stores or using distilled water for filling the
radiator.

--
DougW

Re: Overheating CJ7, the story so far
 

SB did pass the time by typing:
> Where does this crap come from? water in the system that's rusting parts?
> Or oil seeping in to the coolant?

not usually oil, that's a blown head gasket. It comes from having a poor PH
balance in the coolant or excess minerals in the water used to fill the system.
Long term it comes from corrosion of the sacrificial anode then the radiator
and block.

Another source is that leak-stop stuff. Oh, it works in a pinch (on small
leaks/seeps) but I've seen radiators with at least a pint of the stuff settled
in the bottom.

If your in an area with high mineral content or acidic water you would be better
off using the 50/50 mix sold in stores or using distilled water for filling the
radiator.

--
DougW

Re: Overheating CJ7, the story so far
 

Ok....

To start, the drain for flushing the block is a square plug under the
rear exhaust manifold on the side of the block.

Having the temp gauge in the intake manifold is a valid place for it.
Air bubbles from a blown head gasket or trapped air 'will' affect the
gauge readings.

Do you have a clutch on the fan? If so, it may be bad. To test heat up
the engine and have someone shut it down while you watch the fan. A hot
fan will stop spinning immediately. if it keeps on free wheeling, it's
dead. No need to look any more, you have found it.

If the fan clutch is good, then how is the rad itself? What do the
cores look like when you look inside. If they are all gummed up with
deposits, it needs a serious clean or 'rod' job where they physically
scrape the crap out.

Do you have coolant flow? Open up the rad cap and heat it up with the
cap off to see if the pump is pumping.

This also allows you to check for a bad head gasket. A bad head gasket
will foam up the coolant. It will look like someone put dish soap in it
like mine shown here: http://www.imagestation.com/album/?id=4290636987

(your readings 'do' indicate a blown head gasket at # 6 to me by the
way)

That's all I can think of right now, good luck.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

David Harmon wrote:
>
> Friday, April 30
> On trip to Irvine, it became apparent to me that my Jeep engine was
> overheating too much to ignore.
>
> My temperature gauge has been dead for years, because of a failed
> voltage regulator in the fuel gauge that supplies both of them.
> http://www.monsterslayer.com/jeep/Gauges.htm
>
> Tuesday, May 4.
> Whereas I already had a spare thermostat ready to go, that became the
> first thing to attack. Before starting, checked the new thermostat in a
> pot of boiling water on the stove; it opens as expected. Pulled old
> thermostat, put in new one. Jeep still overheats. Old thermostat in
> pot on stove acts just like the new one.
>
> Wednesday, May 5.
> Went to Pep Boys, bought a bunch of stuff. A nice mechanical water temp
> gauge. Prestone flush kit, consisting of tee fitting that goes in the
> heater hose for hooking up to garden hose, and a cheesy tube to divert
> the overflow a couple of inches away in a chosen direction. Bottle of
> flush chemical, label says it has sodium citrate in it. Bottle of water
> pump lubricant and three bottles of antifreeze. Cheesy Prestone
> hydrometer.
>
> Installed the temp gauge in a fitting in the water passages in the
> intake manifold that, for some odd reason, I believed was where it was
> supposed to go. Readings very squirrely.
>
> Modified the Prestone overflow tube by adding a hose fitting, so with a
> second garden hose I can route the overflow someplace inoffensive
> instead of dumping it on my shoes.
>
> Thursday, May 6.
> Figured out that I had hooked up the new gauge wrong. The fitting on
> the manifold is the wrong place. The right place to connect it is on
> the block like God intended it. The gauge sensor is to big to fit
> there. Too bad, and it was such a great fit in the wrong place. Out it
> comes, and again I have no temperature gauge.
>
> Installed Prestone flush kit. Prestone says to put the tee in the upper
> heater hose, where it comes out of the top of the engine. Problem is,
> my heater hose connects on the radiator side of the thermostat, while
> they assume it connects on the engine side. If I connect it on top, I
> will be flushing nothing but the top radiator tank. I connect it in the
> bottom heater hose. That way, the water at least has to go through
> either the heater core or the radiator core to get out.
>
> Drained the radiator. Contents looking like swamp water, more brown
> than green. Hydrometer says there's not much antifreeze in it.
>
> Flushed with water for a while.
>
> Closed it up, added the flush chemical. Drove around the block until
> hot, then let it sit until cool. Drained.
>
> Flushed with water again. Discovered that by squeezing the heater hose
> shut with vice grip pliers I could make sure the water went both ways,
> heater and radiator. Good. Unfortunately, as the thermostat was
> closed, I suspect not much flushing happened in the block water
> passages. I guess a fair amount of rust and/or sludge has come out. but
> I don't know what to compare against. Water coming out is clear.
>
> Filled with good antifreeze and water pump lubricant. The passenger
> compartment heater, which has been almost useless for years, is now
> putting out heat, so at least I did that much good. Jeep still
> overheats.
>
> (H) relates the story of a vehicle having the same sort of problem,
> cured by replacing an old tired radiator cap with one that hold the
> proper pressure. (H) and I make a late night shopping run to Pep
> Boys for a radiator cap and the Despot for some water fittings.
>
> Friday, May 7.
> Hooked up pressure gauge to the Prestone flush port. On a test drive,
> old radiator cap blows off at 10 PSI. Installed new radiator cap.
> New radiator cap blows off at 16 PSI, matching spec. Jeep still
> overheats.
>
> (H) finally talks me in to doing the compression check, to see if I
> have a blown head gasket.
> Cyl PSI PSI (each cylinder checked twice.)
> 1 158 158
> 2 173 173
> 3 158 160
> 4 165 163
> 5 163 163
> 6 150 156
>
> We concluded no blown head gasket.
>
> Talked to (D). He believes I need more flushing of the block water
> passages. And what else is there to consider? That and the water pump.
> So, I thing the water pump has to come off for inspection at least, and
> if it's off then maybe it is a dumb idea to not put a new one on even if
> it looks good. When it is off, that would be the time to flush the
> block. I don't know yet what kind of rig up I can use to flush the
> block.