Lon Stowell wrote:
>
> >
> > Robert Goldpalm wrote:
> >>
> >> Could the cause of this problem be found
> >> within the electronic / contact / sensor input complex?
> >>
> >> Today, no noise at all, so far. No noise at cold start,
> >> no noise during normal driving conditions with a warm
> >> engine. No noise whatsoever.
> >>
> >> So, if it would be a purely mechanical problem such as
> >> piston slap, hydraulic lifters, or carbon build up, why is
> >> there no noise today?
> >>
> >> I am living in the tropics (Thailand) with a very high humidity
> >> of around 80-90%. Could it be, that somewhere, an electronic
> >> contact or a wrong sensor input causes the engine to produce
> >> this ticking / knocking sounds sometimes?
>
> Approximately 11/10/03 09:04, Mike Romain uttered for posterity:
>
> > Did you check your fan clutch?
>
> Does the vibration damper on the 4.0 get loose and sound
> pretty close to a piston knock? Have had it happen on
> other engines, dunno if the 4.0 unit can do it. Actually
> on the other engine it wasn't loose, it had a big crack
> in it that made the most noise when cold.
>
> --

Yes, it can go bad, but usually it starts eating the fan belt before it
knocks from what I have read.

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

 

Lon Stowell wrote:
>
> >
> > Robert Goldpalm wrote:
> >>
> >> Could the cause of this problem be found
> >> within the electronic / contact / sensor input complex?
> >>
> >> Today, no noise at all, so far. No noise at cold start,
> >> no noise during normal driving conditions with a warm
> >> engine. No noise whatsoever.
> >>
> >> So, if it would be a purely mechanical problem such as
> >> piston slap, hydraulic lifters, or carbon build up, why is
> >> there no noise today?
> >>
> >> I am living in the tropics (Thailand) with a very high humidity
> >> of around 80-90%. Could it be, that somewhere, an electronic
> >> contact or a wrong sensor input causes the engine to produce
> >> this ticking / knocking sounds sometimes?
>
> Approximately 11/10/03 09:04, Mike Romain uttered for posterity:
>
> > Did you check your fan clutch?
>
> Does the vibration damper on the 4.0 get loose and sound
> pretty close to a piston knock? Have had it happen on
> other engines, dunno if the 4.0 unit can do it. Actually
> on the other engine it wasn't loose, it had a big crack
> in it that made the most noise when cold.
>
> --

Yes, it can go bad, but usually it starts eating the fan belt before it
knocks from what I have read.

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

 

Mike Romain did pass the time by typing:
> Lon Stowell wrote:
>>
>>>
>>> Robert Goldpalm wrote:

---8<---

>>> Did you check your fan clutch?
>>
>> Does the vibration damper on the 4.0 get loose and sound
>> pretty close to a piston knock? Have had it happen on
>> other engines, dunno if the 4.0 unit can do it. Actually
>> on the other engine it wasn't loose, it had a big crack
>> in it that made the most noise when cold.

> Yes, it can go bad, but usually it starts eating the fan belt before it
> knocks from what I have read.

That's my understanding also.

A mechanic down in Biloxi told me this trick. YMMV
Take a feel of the rubber spacer in the vibration damper,
if it's sticking out or the surfaces aren't even then it is
starting to turn loose.

He also mentioned running a razor blade around the face and checking
to see if any rubber comes off. Although I just go by feel.

I still think taking a mechanics stethoscope to the engine is the best bet.

--
DougW

 

Mike Romain did pass the time by typing:
> Lon Stowell wrote:
>>
>>>
>>> Robert Goldpalm wrote:

---8<---

>>> Did you check your fan clutch?
>>
>> Does the vibration damper on the 4.0 get loose and sound
>> pretty close to a piston knock? Have had it happen on
>> other engines, dunno if the 4.0 unit can do it. Actually
>> on the other engine it wasn't loose, it had a big crack
>> in it that made the most noise when cold.

> Yes, it can go bad, but usually it starts eating the fan belt before it
> knocks from what I have read.

That's my understanding also.

A mechanic down in Biloxi told me this trick. YMMV
Take a feel of the rubber spacer in the vibration damper,
if it's sticking out or the surfaces aren't even then it is
starting to turn loose.

He also mentioned running a razor blade around the face and checking
to see if any rubber comes off. Although I just go by feel.

I still think taking a mechanics stethoscope to the engine is the best bet.

--
DougW

 

Mike Romain did pass the time by typing:
> Lon Stowell wrote:
>>
>>>
>>> Robert Goldpalm wrote:

---8<---

>>> Did you check your fan clutch?
>>
>> Does the vibration damper on the 4.0 get loose and sound
>> pretty close to a piston knock? Have had it happen on
>> other engines, dunno if the 4.0 unit can do it. Actually
>> on the other engine it wasn't loose, it had a big crack
>> in it that made the most noise when cold.

> Yes, it can go bad, but usually it starts eating the fan belt before it
> knocks from what I have read.

That's my understanding also.

A mechanic down in Biloxi told me this trick. YMMV
Take a feel of the rubber spacer in the vibration damper,
if it's sticking out or the surfaces aren't even then it is
starting to turn loose.

He also mentioned running a razor blade around the face and checking
to see if any rubber comes off. Although I just go by feel.

I still think taking a mechanics stethoscope to the engine is the best bet.

--
DougW

 

On Mon, 10 Nov 2003 18:19:23 UTC Mike Romain <romainm@sympatico.ca>
wrote:

> Lon Stowell wrote:
> >
> > >
> > > Robert Goldpalm wrote:
> > >>
> > >> Could the cause of this problem be found
> > >> within the electronic / contact / sensor input complex?
> > >>
> > >> Today, no noise at all, so far. No noise at cold start,
> > >> no noise during normal driving conditions with a warm
> > >> engine. No noise whatsoever.
> > >>
> > >> So, if it would be a purely mechanical problem such as
> > >> piston slap, hydraulic lifters, or carbon build up, why is
> > >> there no noise today?
> > >>
> > >> I am living in the tropics (Thailand) with a very high humidity
> > >> of around 80-90%. Could it be, that somewhere, an electronic
> > >> contact or a wrong sensor input causes the engine to produce
> > >> this ticking / knocking sounds sometimes?
> >
> > Approximately 11/10/03 09:04, Mike Romain uttered for posterity:
> >
> > > Did you check your fan clutch?
> >
> > Does the vibration damper on the 4.0 get loose and sound
> > pretty close to a piston knock? Have had it happen on
> > other engines, dunno if the 4.0 unit can do it. Actually
> > on the other engine it wasn't loose, it had a big crack
> > in it that made the most noise when cold.
> >
> > --
>
> Yes, it can go bad, but usually it starts eating the fan belt before it
> knocks from what I have read.

First hand observation: right on. If it's gotten to the point of
being loose enough to knock you're probably too poor from replacing
belts to do anything about it.

A worn out water pump will also do this - but not for long. The other
culprit is the power steering pump and that can go on for a while
since the big impeller just whops the case. All of these thing
produce more of a thumb than a hard knock, tho.

I think your suggestion of a stethascope is the best one - localize
the noise then let us all guess.

--
Will Honea <whonea@codenet.net>

 

On Mon, 10 Nov 2003 18:19:23 UTC Mike Romain <romainm@sympatico.ca>
wrote:

> Lon Stowell wrote:
> >
> > >
> > > Robert Goldpalm wrote:
> > >>
> > >> Could the cause of this problem be found
> > >> within the electronic / contact / sensor input complex?
> > >>
> > >> Today, no noise at all, so far. No noise at cold start,
> > >> no noise during normal driving conditions with a warm
> > >> engine. No noise whatsoever.
> > >>
> > >> So, if it would be a purely mechanical problem such as
> > >> piston slap, hydraulic lifters, or carbon build up, why is
> > >> there no noise today?
> > >>
> > >> I am living in the tropics (Thailand) with a very high humidity
> > >> of around 80-90%. Could it be, that somewhere, an electronic
> > >> contact or a wrong sensor input causes the engine to produce
> > >> this ticking / knocking sounds sometimes?
> >
> > Approximately 11/10/03 09:04, Mike Romain uttered for posterity:
> >
> > > Did you check your fan clutch?
> >
> > Does the vibration damper on the 4.0 get loose and sound
> > pretty close to a piston knock? Have had it happen on
> > other engines, dunno if the 4.0 unit can do it. Actually
> > on the other engine it wasn't loose, it had a big crack
> > in it that made the most noise when cold.
> >
> > --
>
> Yes, it can go bad, but usually it starts eating the fan belt before it
> knocks from what I have read.

First hand observation: right on. If it's gotten to the point of
being loose enough to knock you're probably too poor from replacing
belts to do anything about it.

A worn out water pump will also do this - but not for long. The other
culprit is the power steering pump and that can go on for a while
since the big impeller just whops the case. All of these thing
produce more of a thumb than a hard knock, tho.

I think your suggestion of a stethascope is the best one - localize
the noise then let us all guess.

--
Will Honea <whonea@codenet.net>

 

On Mon, 10 Nov 2003 18:19:23 UTC Mike Romain <romainm@sympatico.ca>
wrote:

> Lon Stowell wrote:
> >
> > >
> > > Robert Goldpalm wrote:
> > >>
> > >> Could the cause of this problem be found
> > >> within the electronic / contact / sensor input complex?
> > >>
> > >> Today, no noise at all, so far. No noise at cold start,
> > >> no noise during normal driving conditions with a warm
> > >> engine. No noise whatsoever.
> > >>
> > >> So, if it would be a purely mechanical problem such as
> > >> piston slap, hydraulic lifters, or carbon build up, why is
> > >> there no noise today?
> > >>
> > >> I am living in the tropics (Thailand) with a very high humidity
> > >> of around 80-90%. Could it be, that somewhere, an electronic
> > >> contact or a wrong sensor input causes the engine to produce
> > >> this ticking / knocking sounds sometimes?
> >
> > Approximately 11/10/03 09:04, Mike Romain uttered for posterity:
> >
> > > Did you check your fan clutch?
> >
> > Does the vibration damper on the 4.0 get loose and sound
> > pretty close to a piston knock? Have had it happen on
> > other engines, dunno if the 4.0 unit can do it. Actually
> > on the other engine it wasn't loose, it had a big crack
> > in it that made the most noise when cold.
> >
> > --
>
> Yes, it can go bad, but usually it starts eating the fan belt before it
> knocks from what I have read.

First hand observation: right on. If it's gotten to the point of
being loose enough to knock you're probably too poor from replacing
belts to do anything about it.

A worn out water pump will also do this - but not for long. The other
culprit is the power steering pump and that can go on for a while
since the big impeller just whops the case. All of these thing
produce more of a thumb than a hard knock, tho.

I think your suggestion of a stethascope is the best one - localize
the noise then let us all guess.

--
Will Honea <whonea@codenet.net>

 

Thanks for all the input so far.

Checking around with an improvised stethoscope, the noise seems to
come
from the engine close to cylinder ( 6 ?) , close to the place, where
the
PCV is located.

Take today's history for example. Started the cold (it's the tropics)
engine. No noise at all. Went to the local mall about 3 miles away,
and
no noise during the drive there. While slowly cruising at about 1,500
rpm through the parking area, the noise (more like a knocking, not a
ticking) appeared.
During idle, the knocking was still there, then stopped. With the car
parked, raving the engine up to about 1,500 to 2000 rpm and letting it
slow down to idle again, the symptoms came back during idle for about
30 Seconds to a minute, then stopped.

I decided to drive strait to the dealer who is only away another few
miles. On
the way there, no noise at all. At the dealer, only a very slight
ticking sound, but no knocking.

Every time I am at the dealer, there is only a ticking, but never a
strong knocking.
When this metallic knocking sound appears, you can hear it very
clearly, even quit far away from the car.

From reading through similar messages, I would say, it sounds perhaps
like the
"Piston Slap", but since I have a '99 model, this particular problem
should not
apply to my engine I guess.

 

Thanks for all the input so far.

Checking around with an improvised stethoscope, the noise seems to
come
from the engine close to cylinder ( 6 ?) , close to the place, where
the
PCV is located.

Take today's history for example. Started the cold (it's the tropics)
engine. No noise at all. Went to the local mall about 3 miles away,
and
no noise during the drive there. While slowly cruising at about 1,500
rpm through the parking area, the noise (more like a knocking, not a
ticking) appeared.
During idle, the knocking was still there, then stopped. With the car
parked, raving the engine up to about 1,500 to 2000 rpm and letting it
slow down to idle again, the symptoms came back during idle for about
30 Seconds to a minute, then stopped.

I decided to drive strait to the dealer who is only away another few
miles. On
the way there, no noise at all. At the dealer, only a very slight
ticking sound, but no knocking.

Every time I am at the dealer, there is only a ticking, but never a
strong knocking.
When this metallic knocking sound appears, you can hear it very
clearly, even quit far away from the car.

From reading through similar messages, I would say, it sounds perhaps
like the
"Piston Slap", but since I have a '99 model, this particular problem
should not
apply to my engine I guess.