[Guest]

Lost a good weekend jeeping in Tellico because my ride overheated going to the trails. I had experienced this a few months back but thought I had taken the necessary corrective action. On that occasion the I6-258 w/MPI overheating while idleing down the trail, no problem while running at hwy speed. Changed the thermostat, coolant and radiator cap added fan shroud. No problem driving around town for 2 months.....trailer it to Tellico 500 miles....and it over heats going to the registration gate. I pulled the thermostat completely added water/coolant mix and ran to trail head hoping it was a bad thermostat. Nope...still over heated. Rode shotgun all weekend, pulled wench cable and lent a hand fixing others rigs.
Suggestions as to the problem: Timeing is off? Distributor is bad? Radiator is blocked? Water pump is gone? Head gasket is leaking engine pressure into coolant system preventing proper coolant flow? My shade tree mechanic thinks my catalytic convertor is disintegrating and causing sporatic blockage. He is ready to punch out the remainder and run it open.
what do you all think?
-Will

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[247]

I am no expert, but what it sounds like to me is that your coolant is not flowing properly. I have 2 jeeps with inline sixes and they have been proven to be an engine that runs pretty hot no matter what. They never get over 210 degrees though. If your water pump was out your jeep would overheat even at highway speeds. The best advise I can give you is to have your cooling system flushed. If this does not work, then you should have your radiator flushed by a radiator shop. At the advise of an expert, put a new cap on your radiator with as high poundage as your radiator will take. Increasing the internal pressure of your radiator raises the boiling point of the fluid inside, which in turn, increases the temperature that your engine will overheat. All of this will be effective if the circulation in your cooling system IS WORKING!! I have never had the catalytic converter cause any overheating problems when it is clogged up. The only problem I had when the CC was clogged was a loss of power. Hope this helps your situation./wwwthreads_images/icons/smile.gif

/wwwthreads_images/icons/cool.gif'46 CJ 2-A Rusty, but still fun to drive and easy to work on./wwwthreads_images/icons/cool.gif

 

[CJDave]

/wwwthreads_images/icons/tongue.gif (1) Make sure that your thermostat has a hole drilled in it. (2) Make sure that your lower radiator hose isn't sucking flat at cruise RPM. (3) Verify that there IS flow by removing the top heater hose....if you have pressure there, it usually means flow, then check the radiator to visually see the flow at that end.(4) Double-check the thermostat by using a pan on the stove and a thermometer. (5) Pull the water pump and check for an impeller that may be loose on the shaft.(6) Check to see that the thermostatically-controlled fan is clutching in and out as needed.(6) Make sure that the fan is a good fit in the radiator shroud. (7) Take two asprin and call me in the morning/wwwthreads_images/icons/laugh.gif

CJDave
Quadra-Trac modified by the crack moonguy/wwwthreads_images/icons/wink.gif/wwwthreads_images/icons/smile.gif/wwwthreads_images/icons/tongue.gif transfer case team.

 

[JimmyZ]

$.02......lower rad. hose is under suction even when system is pressurized. Weak hose can collapse and restrick flow. ???? Good Luck.

 

[GeeAea]

I'd go with the impeller or the fan clutch (or both). Most of the other causes would get worse at highway speeds. Some impellers don't have to be loose......just erroded enough to do a poor job at idle (rare but possible).

GeeAea

Figures don't lie ....... but liars sure do figure.

 

[IN2DEEP]

You pulled the thermostat after it over heated? No replacement? If you don't have a thermostat, water will constantly heat up (No time for it to sit in radiator and cool). If you just removed your thermostat, and just "walked" the trails, I'd think it would over-heat in a hurry. No thermostat works fine on highway, but stop and go...... you are just asking for trouble.

IN2DEEP 78 CJ5 302 FORD T176/D300 35" BFGS

 

[CJDave]

/wwwthreads_images/icons/tongue.gif In-Two-Deep is exactly right.....the water will flow too fast for it to absorb any heat or give up any heat/wwwthreads_images/icons/crazy.gif

CJDave
Quadra-Trac modified by the crack moonguy/wwwthreads_images/icons/wink.gif/wwwthreads_images/icons/smile.gif/wwwthreads_images/icons/tongue.gif transfer case team.