I replaced the coolant and the thermostat in my 97 legacy.....everyone told me that my head gasket was gone on my car and that was the problem but when i did the coolant change (i put the manual stated 6 litres in but only drained 3 litres) and replaced the thermostat the temp would go up and then come back down.......i would get off the highway and get stuck at a red and the temp would go up but as soon as i would start moving it would go down again....this would happen a few times but eventually the temp would stay up and the heating in the car would not work.

 

do you still think its the head gasket?

 

thanks

Something is causing it to have an air bleed in the system. Head gasket can cause it but you really need to rent or borrow a cooling system pressure tester and pump the system up to like 13PSI and see if maybe you have a pinhole leak that you cant normally find or something. If you don't its probably a Head Gasket. Autozone will loan them to you.

im going to get my car checked out tomorrow ill suggest that

Sounds to me like you have an airlock in your cooling system, ummm

you have to get all the air out of the system

Been experiencing something similar with my 97 OBW as well. Before you jump to the head gasket conclusion though, be sure you've got ALL the air out of the system and replace your radiator cap. It's going to be a few days of burping the system for me before I decide whether it's time for a HG job.

#1 reason for overheating after servicing the cooling system is an air pocket.

 

nipper

I think I may finally be getting my head around this whole HG/overheating issue with these cars.

 

HG failure can definitely cause overheating.

 

But overheating can be caused by other factors, like air in the system. Something to be wary of especially after you've drained/refilled the system.

 

I think overheating can also lead to a HG failure though, so it's never a good idea to keep driving once the car's overheated. This is what my wife unknowingly did the other day, and is why I'm still not certain if I'll be needing a HG job or not just yet.

 

Another thing I found interesting is the whole airplane/HG thread, which implied that HG failure is somewhat intermittent, i.e. it only happens at high temps/RPMs. Again though, similar symptoms to the air pocket in the system. If you subscribe to this train of thought, your car may have a 'blown' head gasket but run normally, only showing symptoms after long or arduous trips. It's a tricky beast that's for sure. But the way I see it my 97 has 140k miles on it, so I wouldn't say I'm a victim of the dreaded 2.5DOHC head gasket curse. Hell, I had to have the head gasket done on my 91 Toyota 22RE at 120k miles earlier this year, although I'm almost positive that was caused by a "Power Flush" service I had done at Oilstop.

hey i got it checked out and its the head gasket.....there was exhaust coming out of the rad

Bummer dude.

It's looking like I'm in the same boat as you Big Blue. Got a quote from my mechanic of $1200-$1300 for the head gasket and timing belt, and he'd get it done in 4 or 5 days! So to avoid a catastrophic failure when we drive 1000 miles next month, I'm just gonnna bite the bullet and have it done.

It is expensive but the nice thing is that you should not have to worry about failure after that. I'm glad I got my head gaskets replaced a few years ago as the peace of mind makes it worth it.