Re: Followup-- 2000 JGC V-8 still overheating
 

I would be thinking that the thermostat that is supposed to open at 195
has serious issues.

You should have burned your finger in 205 coolant. Water boils just
slightly hotter than that....

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

James wrote:
>
> I posted this several weeks ago, and got a lot of thoughtful replies. No
> remedy yet, this is just an update.
>
> Last week, I drove home from vacation, a 500 mile trip. I noticed
> repeatedly that the temp at 65 mph would be in the 205-210 range, but five
> minutes after I go up to 75 mph, the temp would increase to around 225. I
> did this test over and over, and got the same results.
>
> Someone suggested that to check the (new) thermostat, to take the pressure
> cap off when the engine is cold, start the engine, and see if there is water
> flow (I assume there should be flow after the thermostat opens up). I did
> this test, while the outside temp is 72 degrees. From the first engine
> start, I saw no water flow. None.
>
> I let the engine run for 45 minutes. The gauge went to 205 and stayed
> there. At no time did I see a water flow, even after 45 minutes of running
> at idle. I put my finger in the water and it was **warm** but not at all
> hot. Just warm. It never got hot.
>
> Should I have seen water flow after the temp went to 205, and the engine
> ran for 45 mins ??
>
> Any further comments will be appreciated.
>
> --James--
>
> ----------------------------------------------------------------------------
> -------------------------------
>
> This is a V-8, 120 K miles. It usually runs around 200-210
> > degrees. During last six months or so, it will go up the 235 degrees when
> > traveling over 70 mph. It will also do this when going up a medium
> > incline, even at very slow speed.
> >
> > It stays 100% normal at slow speeds, and at idle, such as at a traffic
> > light.
> >
> > Fan clutch was replaced fairly recently, that DID relate to heating some
> > at idle.
> >
> > I am thinking either I need radiator work or a new radiator OR that I
> > may have a bad thermostat. I suppose I could also have a defective
> > water pump at high speeds, but that wouldn't explain why it overheats on
> > medium inclines even at slow speeds.
> >
> > BTW, some folks may say 235 degrees is normal under some circumstances. I
> > can assure you that this is NOT normal, as I have driven this car for six
> > years and I know how it performs.
> >
> > What is most likely culprit? Themostat/Water Pump/Radiator
> >
> > If it is radiator, is it worth it to have it re-rodded, or is it best just
> > to install a new radiator?
> >
> > As a non-mechanic, are these any tests I can do to narrow it down more?
> > (Water pump does not leak).
> >
> >
> > Thanks for any tips !!!
> >
> > --James--

Re: Followup-- 2000 JGC V-8 still overheating
 

I would be thinking that the thermostat that is supposed to open at 195
has serious issues.

You should have burned your finger in 205 coolant. Water boils just
slightly hotter than that....

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

James wrote:
>
> I posted this several weeks ago, and got a lot of thoughtful replies. No
> remedy yet, this is just an update.
>
> Last week, I drove home from vacation, a 500 mile trip. I noticed
> repeatedly that the temp at 65 mph would be in the 205-210 range, but five
> minutes after I go up to 75 mph, the temp would increase to around 225. I
> did this test over and over, and got the same results.
>
> Someone suggested that to check the (new) thermostat, to take the pressure
> cap off when the engine is cold, start the engine, and see if there is water
> flow (I assume there should be flow after the thermostat opens up). I did
> this test, while the outside temp is 72 degrees. From the first engine
> start, I saw no water flow. None.
>
> I let the engine run for 45 minutes. The gauge went to 205 and stayed
> there. At no time did I see a water flow, even after 45 minutes of running
> at idle. I put my finger in the water and it was **warm** but not at all
> hot. Just warm. It never got hot.
>
> Should I have seen water flow after the temp went to 205, and the engine
> ran for 45 mins ??
>
> Any further comments will be appreciated.
>
> --James--
>
> ----------------------------------------------------------------------------
> -------------------------------
>
> This is a V-8, 120 K miles. It usually runs around 200-210
> > degrees. During last six months or so, it will go up the 235 degrees when
> > traveling over 70 mph. It will also do this when going up a medium
> > incline, even at very slow speed.
> >
> > It stays 100% normal at slow speeds, and at idle, such as at a traffic
> > light.
> >
> > Fan clutch was replaced fairly recently, that DID relate to heating some
> > at idle.
> >
> > I am thinking either I need radiator work or a new radiator OR that I
> > may have a bad thermostat. I suppose I could also have a defective
> > water pump at high speeds, but that wouldn't explain why it overheats on
> > medium inclines even at slow speeds.
> >
> > BTW, some folks may say 235 degrees is normal under some circumstances. I
> > can assure you that this is NOT normal, as I have driven this car for six
> > years and I know how it performs.
> >
> > What is most likely culprit? Themostat/Water Pump/Radiator
> >
> > If it is radiator, is it worth it to have it re-rodded, or is it best just
> > to install a new radiator?
> >
> > As a non-mechanic, are these any tests I can do to narrow it down more?
> > (Water pump does not leak).
> >
> >
> > Thanks for any tips !!!
> >
> > --James--

Re: Followup-- 2000 JGC V-8 still overheating
 

I would be thinking that the thermostat that is supposed to open at 195
has serious issues.

You should have burned your finger in 205 coolant. Water boils just
slightly hotter than that....

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

James wrote:
>
> I posted this several weeks ago, and got a lot of thoughtful replies. No
> remedy yet, this is just an update.
>
> Last week, I drove home from vacation, a 500 mile trip. I noticed
> repeatedly that the temp at 65 mph would be in the 205-210 range, but five
> minutes after I go up to 75 mph, the temp would increase to around 225. I
> did this test over and over, and got the same results.
>
> Someone suggested that to check the (new) thermostat, to take the pressure
> cap off when the engine is cold, start the engine, and see if there is water
> flow (I assume there should be flow after the thermostat opens up). I did
> this test, while the outside temp is 72 degrees. From the first engine
> start, I saw no water flow. None.
>
> I let the engine run for 45 minutes. The gauge went to 205 and stayed
> there. At no time did I see a water flow, even after 45 minutes of running
> at idle. I put my finger in the water and it was **warm** but not at all
> hot. Just warm. It never got hot.
>
> Should I have seen water flow after the temp went to 205, and the engine
> ran for 45 mins ??
>
> Any further comments will be appreciated.
>
> --James--
>
> ----------------------------------------------------------------------------
> -------------------------------
>
> This is a V-8, 120 K miles. It usually runs around 200-210
> > degrees. During last six months or so, it will go up the 235 degrees when
> > traveling over 70 mph. It will also do this when going up a medium
> > incline, even at very slow speed.
> >
> > It stays 100% normal at slow speeds, and at idle, such as at a traffic
> > light.
> >
> > Fan clutch was replaced fairly recently, that DID relate to heating some
> > at idle.
> >
> > I am thinking either I need radiator work or a new radiator OR that I
> > may have a bad thermostat. I suppose I could also have a defective
> > water pump at high speeds, but that wouldn't explain why it overheats on
> > medium inclines even at slow speeds.
> >
> > BTW, some folks may say 235 degrees is normal under some circumstances. I
> > can assure you that this is NOT normal, as I have driven this car for six
> > years and I know how it performs.
> >
> > What is most likely culprit? Themostat/Water Pump/Radiator
> >
> > If it is radiator, is it worth it to have it re-rodded, or is it best just
> > to install a new radiator?
> >
> > As a non-mechanic, are these any tests I can do to narrow it down more?
> > (Water pump does not leak).
> >
> >
> > Thanks for any tips !!!
> >
> > --James--

Re: Followup-- 2000 JGC V-8 still overheating
 

Yes, Mike, I agree with your comments. My mechanic put in a new
thermostat just several months ago. I wonder if it was installed backwards.
Could that be ?


--James--

Re: Followup-- 2000 JGC V-8 still overheating
 

Yes, Mike, I agree with your comments. My mechanic put in a new
thermostat just several months ago. I wonder if it was installed backwards.
Could that be ?


--James--

Re: Followup-- 2000 JGC V-8 still overheating
 

Yes, Mike, I agree with your comments. My mechanic put in a new
thermostat just several months ago. I wonder if it was installed backwards.
Could that be ?


--James--

Re: Followup-- 2000 JGC V-8 still overheating
 

Yes, Mike, I agree with your comments. My mechanic put in a new
thermostat just several months ago. I wonder if it was installed backwards.
Could that be ?


--James--

Re: Followup-- 2000 JGC V-8 still overheating
 

Or just plain a bad one.... That happens. I think yours must be
opening 'some' or you would get a boil over.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

James wrote:
>
> Yes, Mike, I agree with your comments. My mechanic put in a new
> thermostat just several months ago. I wonder if it was installed backwards.
> Could that be ?
>
> --James--

Re: Followup-- 2000 JGC V-8 still overheating
 

Or just plain a bad one.... That happens. I think yours must be
opening 'some' or you would get a boil over.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

James wrote:
>
> Yes, Mike, I agree with your comments. My mechanic put in a new
> thermostat just several months ago. I wonder if it was installed backwards.
> Could that be ?
>
> --James--

Re: Followup-- 2000 JGC V-8 still overheating
 

Or just plain a bad one.... That happens. I think yours must be
opening 'some' or you would get a boil over.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

James wrote:
>
> Yes, Mike, I agree with your comments. My mechanic put in a new
> thermostat just several months ago. I wonder if it was installed backwards.
> Could that be ?
>
> --James--