Please help: Question on overheating

[kingcaii]

So my 06 LGT gave me some erratic movement of the temp gauge today and yesterday. My mental acuity and powers of deduction and reasoning (LOL) lead me to believe that the culprit is the thermostat. I've read that it's possible that the banjo bolt can get clogged, starve the turbo, and cause it to overheat and eventually break-- but I don't think that's what's happening here.

 

At low speeds are the only times that the temp gauge has gone above half, and its happened after the car has been on for only a few minutes, AND also when the car has been running for an hour (I've been on the highway for that hour with no problems during that trip). So what I'm guessing is that the thermostat is faulty and has problems opening/closing during the gas/break/gas/break of local driving.

 

*I'd also like to note that the coolant level in the reservoir was ABOVE the Full line.*

 

Just to test that it wasn't (hopefully) the turbo, I drove home (another hour long trip) today and took it easy most of the ride, then smashed some once I got close to my exit. The temp gauge didn't budge from its safe position.

 

I'm gonna get to changing the thermostat tomorrow afternoon, I just want to get anyone/everyone's input on whether I'm looking at this situation the right way, or if i'm missing something? Thanks in advance guys.

[apexi]

This isn't my strongest area, but I'll throw out my .02

 

So I just want to clarify, it only happens at low speeds? And the problem only happens at low speeds regardless of whether the car had been driven a lot or a little bit?

 

I think you have the right idea, I would try the thermostat first.

 

After doing a little research, I'm hoping that it's the thermostat, and not the head gasket. How many miles are on the car? Do the radiator fans come on when the engine reaches operating temp?

[kingcaii]

This isn't my strongest area, but I'll throw out my .02

 

So I just want to clarify, it only happens at low speeds? And the problem only happens at low speeds regardless of whether the car had been driven a lot or a little bit?

 

I think you have the right idea, I would try the thermostat first.

 

After doing a little research, I'm hoping that it's the thermostat, and not the head gasket. How many miles are on the car? Do the radiator fans come on when the engine reaches operating temp?

 

Yes only happens at low speeds

 

Yes regardless of how long the car has been on

 

Car has 105k miles on it

 

Yes the radiator fans come on when the engine reaches operating temp

 

I changed the thermostat and radiator cap a few hours ago... To no effect, car seemed fine, drove home, car slightly overheating soon after getting off the highway, with fan running. Also, the temp gauge never gets to the red, usually goes to about 3/4 (or slightly higher) and calms down shortly after. Thoughts? Please? :/

[apexi]

I noticed you just recently got this car a month and a half ago. Do you know if any work was done on the car before you bought it, such as a coolant flush? It sounds like there is an air pocket in the cooling system. Does the cars inside heat work ok? The problem probably isn't a bad heater core, but you never know, worth a shot. Did you buy the car from a dealership, private party, or private car dealership? Hopefully the previous owner didn't get rid of the car because it had a bad head gasket. Without doing a hydrocarbon test, you could see if you notice bubbles in the coolant overflow tank.

[Max Capacity]

At that mileage the timing belt is do to be replaced, was that done ?

 

 

You need to burp the coolant system.

[kingcaii]

At that mileage the timing belt is do to be replaced, was that done ?

 

 

You need to burp the coolant system.

 

Thanks, I'm going to try that before I head to work this morning. From what I found scouring the 'net, I think you're right. Elevating the passenger side, burping the secondary coolant reservoir (I briefly burped the radiator when changing the thermostat and rad cap yesterday, but I did nothing with that secondary reservoir) and then filling it... Sound about right?

 

And yes I got the car recently, month and a half is about right. Bought used from a private owner. He handed me a pile of receipts from work performed by his local Suby dealership and he claimed that he kept up with the recommended maintenance. I do believe he said that the timing belt was changed recently-- I'll have to sort through those receipts.

 

Yes the heat in the car works, I've noticed no problems with that at all. Probably needs... the other belt changed (forgive me I forget the name). I know I get slight squeal when I turn the A/C on (which is rarely, I hardly use A/C), so that corresponding belt needs to be changed.

[GEORGEROV]

Next time you get it up to temperature check the top and bottom radiator hoses are about as warm as each other .