I have a 97 5.2 1500 4x2. Just replaced motor (used) & tranny (new) and drove it today for the first time. This truck was not running when I bought it.

The temp goes up to around 225-235 and kind of hangs out there, seems pretty high to me. Thing that made it more confusing is that the hoses do not build up any pressure nor do I see any leaks anywhere. I do not think that the fluid is circulating through the motor although I dont know for sure. The water level seems exactly the same, like the thermostat never opened. But is it was stuck, I assume there would be pressure built up...right?? I replaced the radiator cap & still no pressure builds up and the temp stays the same. No water in the oil so not a head gasket problem.

1) I do not know id this temp normal for this truck? 2) with no leaks, why would the system not build any pressure? 3)could this be a thermostat issue?

Anybody got any ideas on what to check?? Thanks

 

Thats way too hot. You sure it isn't a clogged radiator?

 

That temp seems a little high. I think most thermostats are set for 190-200 degrees stock. A lot of people replace them with 180 degree t-stats.

I would think either your water pump is not being driven, or your water pump is damaged. Double check the belt to ensure it is properly connected to the water pump.

I wouldn't think this would be related to the t-stat. You can always pull it out and see if it opens up in a pot of boiling water.

The good news is that t-stats and water pumps are generally not too expensive, it's the PITA of getting to them to replace them.

And after reading the previous post... if you have access to a non contact thermometer, you can see if there are any cold spots in your radiator... that would indicate blockage.

Also... does the temp keep climbing or does it level off? If it levels off... it may more likely be a clogged/leaky radiator. Just because you can see a leak... doesn't mean it isn't there.


Good luck,
Cartman

 

Thanks for the input. In the meantime I just uncapped the radiator & let it run for a while. I can see no movement of the water in the radiator at all, it is just still. The water does get pretty hot though. The fan is spinning so I am guessing the waterpump is ok.

I like the idea of the clogged radiator, wats the best or easiest way to check it/clean it?


I did have another thought that scared me. If the intake gaskets were put on reversed or backwards could that block off the water passages in the heads & stop the flow? I did put on new gaskets, I know the intake ports matched up 100% w/ the gaskets but I dont remember if I checked the water ports or not. What do you think?

 

You can not block the water ports because there are two on each side and the gaskets are reversible so that wouldnt be th eproblem. I have the same problem too the temp is right at the farthest white line but not overheating. I am still trying to find the source of the problem

 

No pressure building but the water gets hot? That doesn't make sense to me. The pressure doesn't build because the water circulates. The pressure builds cause the water gets hot and expands. How are you measuring 'no pressure'?
Also, I don't think you will see water moving when you look through the radiator cap. Do you hear a gurgle noise when you start it or start driving?
Maybe the t-stat is in backwards.

 

If the water were moving, the level should start to rise and want to come out of the radiator with the cap removed.

Replacing the t-stat with a 180º will not solve the problem. I've been battling a similar issue and think part of mine is the missing tarboard. Also, just because the fan is moving doesn't mean anything. Run the engine (with the hood open) and have an assistant watch the fan. Shut the engine off. If the fan stops, it's good, but if the fan keeps spinning, the viscous clutch is worn and the fan isn't doing its job. Mine was doing that as well.

Perchance did you grind off the tab on the t-stat housing? If you did, but didn't install it with the words "FRONT" facing the front of the truck, you could have a trapped air pocket in the upper hose right there. The amount of bend in the t-stat housing is very slight and has to be facing the front of the truck. I had that as well.