what causes truck to overheat at idle...

[dsfii93sport]

Why does it seem that my truck tends to slowly creep towards overheating when I sit at idle a period of time. What could be causing this?

 

[Premier]

Because the truck is cooled by air moving over the radiator, and then cooling the coolant inside. If you are just sitting there, it could over heat... I dont think it will though, or atleast it shouldnt.

 

[dsfii93sport]

Well yeah that is a given, but what I'm saying is my truck does overheat. So what part could be causing this, a weak pump?

 

[raginraj]

bad pump is a possibility but i would check out my coolant first to make sure i had enough and that there was a 50/50 ratio of coolant to water in there.

 

[Premier]

Coolant flush couldnt hurt either. Irecall my X running a lot cooler after I did that. Also, maybe your t-stat isnt opening all the way.

 

[dsfii93sport]

Thank you much.. I'll give her a try

 

[KPT]

Change the t-stat first. A t-stat and gasket shouldn't be more than $5. Flush the system while you are at it.

 

[Sallad420]

Did you check to see if your fan on the Rad is actually spinning? Maybe it's busted and not spinning.

 

[MrShorty]

In addition to the thermostat, fan clutch, and coolant level, I would also make sure the radiator (and AC condenser, if equipped) is clean -- no leaves, dirt, etc. restricting air flow through the radiator.

 

[Majisto]

My girlfriend's Caprice had over-heating problems for a while. Coolant was leaking. Turned out the intake gasket was bad. GM cooling systems are a mess! Also, check that fan clutch...just because it spins doesn't mean it's spinning at the right speed.

 

[paul99explorer]

let it idle in your driveway for a while. if it starts getting hot, check to see if the fan is kicking on. If not, it could very well be your fan switch. They're usually inexpensive and easy to change. If this overheating problem only happens when left at idle for a while, I would suspect the fan isn't working. The reason it doesn't happen while driving is b/c the air moving through the radiator does what the fan is supposed to do when the exploder isn't moving. Since it cools down when moving, that usually means that the water is circulating (I.E.: water pump ok, no clogs, no leaks, etc.) My $ .02, anyway.

 

[dsfii93sport]

well from what I've noticed the fan is on non-stop. But I can't be positive but Im pretty sure I've never seen it off!

I'll check into it some more. I think I'm gonna do a basic flush and new stat etc...

 

[MrShorty]

The fan will always spin with the engine, but the clutch "tightens up" when it gets hot and the fan spins faster to draw more air through the radiator.

 

[dsfii93sport]

Ah ha, now I see how this clutch could be the problem if it were weak and old. If it doesnt tighten up like it used to the fan would spin a bit slower than required, which would explain why sitting at a dead stop for 5 - 10 minutes would start to creep towards hot..