YACT - Overheating Problems...Thermostat?

[PricklyPete]

Originally posted by: Quixfire

Originally posted by: PricklyPete
I don't know how dirty the coolant gets, but it wasn't what I would consider dirty. flushing may have just freed some stuff up in there. I don't know. Regardless it seems to be working fine...hasn't gotten above normal temps yet and I've driven it 40+ miles already (long commute).

That just confirms what I thought, an air pocket in the system. Flushing the coolant removes the air pocket and you thermostat is now working normally.

A pocket will get caught between the coolant and the thermostat creating a barrier to prevent the thermostat from opening due to pressure. Removing this air from the system allow the thermostat to work normally.

I glad you got it fixed.

Me too. Thanks for the help.

 

[GalvanizedYankee]

There is usually a very small hole somewhere on the thermostat that permits air to bleed out of the system.

Flushing the cooling system probably cleared this tiny hole, it's only about .030" in diameter.

Where does this air come from in a filled system? Cavitation at the water pump.

 

[Zenmervolt]

Originally posted by: PricklyPete
The coolant was a little low, but still within the "acceptable" range according to the resevoir.

Did you check it after the car had sat overnight or after driving? Coolant expands a lot when it gets hot, if you checked the fluid after driving, it should have been well above the maximum mark on the reservoir.

ZV

 

[PricklyPete]

Originally posted by: Zenmervolt

Originally posted by: PricklyPete
The coolant was a little low, but still within the "acceptable" range according to the resevoir.

Did you check it after the car had sat overnight or after driving? Coolant expands a lot when it gets hot, if you checked the fluid after driving, it should have been well above the maximum mark on the reservoir.

ZV

I checked it after it had been sitting for at least 3 hours.

 

[Doggiedog]

Wanted to jump aboard this thread with my own problems.

My 95 BMW 325i is overheating too. It says coolant level is low but I've put in coolant several times. There don't seem to be any leaks either. Strange this is, when a car overheats, I was told to blast the fan at hot to help cool it off a bit. However, when I do that, only cold air comes out.

I'm taking it into the shop but was wondering what sorts of problems could be causing it and what the various costs may be?

Thanks.

 

[Ornery]

Be prepared for the worst, and hope for the best. Could be a head gasket... yikes! Could be manifold gasket... ugh. Could be a leak you haven't detected... fat chance.

Good luck.

 

[Doggiedog]

Originally posted by: Ornery
Be prepared for the worst, and hope for the best. Could be a head gasket... yikes! Could be manifold gasket... ugh. Could be a leak you haven't detected... fat chance.

Good luck.

Ugh. I've plowed too much into this car already. I was hoping it would last another year.

 

[Thegonagle]

In my experience, that's usually been a symptom of a too-old radiator that's starting to clog because its never had its coolant changed, but that's always been on 8-12 year old cars. Your car is too new. So check the coolant level (but you already did that before posting, right?), check your belts, replace that thermostat, and if those aren't it, I'd start thinking about replacing the water pump.

EDIT: Never mind. Congrats on the successful fix!