My Truck is a '92- I am posting hear because last July I swapped in the 3.4...

So here is what happened- up until now the truck runs great, temps always stay below half on the stock gauge. At the time of the swap I installed brand new water pump, thermostat and radiator.
Last weekend took a trip with some friends and ran a fairly diificult trail that you drop from about 900 meters down to sea level and then climb back up. On the way up the temps would climb past the half way mark on the gauge and if I did not stop and idle the truck would continue into the red zone. Each time it would climb up I would stop and idle the truck for a few minutes and the temps would come right back to its "happy place" - just below half way on the stock gauge. One time I was really working the truck and by the time I was able to stop and give it a rest the temps hit the red zone.

Any Idea what could be the cause?

Rad, waterpump, thermostat were new last July and the fan clutch seems fine as it brings the temps down when idling.....

Hophead

 

switch to an electric fan. prefferably a FAL. high rev's + low speed + integrated trans cooler = poor cooling.


edit: link to FAL fans on Jeg's.

http://www.jegs.com/v/Flex-a-lite/400

 

Could be an air bubble in the system..

 

Thanks for the replys.....

Thinking of adding an electric fan for those high rev, low speed crawls. But the reason I asked the question here was to see if any else had expirienced something like this with their 3.4. I don't want to band aid fix and miss the real problem.