overheating

[garylau]

I'm about to start replacing the heads on my '97 Lumina. Before I start I'd like to figure out why the car overheated in the first place. Here's what I have checked or replaced prior to the overheating that caused the damage. The coolant was recently changed. I replaced the thermostat and checked the water pump which seemed okay. The fan is also working. I was getting little or no heat inside the car, which seems to indicate the coolant is not flowing properly. I also tried running the car with the radiator open and the front end raised up thinking maybe there was an air pocket somewhere, hoping that would free it. Any ideas?

[IanSzgatti]

before I ramble on... tell us what the exact effect was... head gasket blow-out? Tell us about when it over-heated and what you experienced. There are a few obvious causes, but it's a lot cooler to know exactly what went down leading up to head failure.. spare no detail!!!

[garylau]

Unfortunately I don't have a temp gauge in my car (a feature I think ALL cars should have), so I don't know exactly how hot it was getting or for how long. I noticed it seemed to be running hot so I turned on the heat to see if I had coolant flowing, and there was no heat. The first thing I checked was the coolant level which was good, then the thermostat. It was fine, but I replaced it anyway just for peace of mind. I checked the water pump to see if it was okay, and there was no play in the pulley like I've found in previous bad water pumps. I tried running it with the front end lifted up to try to free up any air pockets. I'm not sure if that works, but someone recommended it to me. I checked the oil just to make sure I hadn't done any damage overheating it, and there was coolant mixed in. I haven't been able to get it in the garage because of a project that has been taking up all my space, but as soon as I get the heads and intake off I'm expecting to find a blown gasket. The heads are being replaced because my valvetrain sounds horrible, probably mostly due to the overheating, and I figure there's a good chance of warpage anyway. I picked up a good used set for a replacement. I'm swapping in a 3400 next spring. I just need to get this thing running well enough to make it until then.

[IsaacHayes]

My friend has a 97 lumina and it has a temp gauge... That's odd yours doesn't I've never heard of that. If you have no heat it's likely your system is clogged from the dexcool turning to sludge. A radiator flush might break it free, then drive some more and then flush it again at a later date to get anymore that's broke free. My friends was overheating and he had no heat and I flushed his and it made it a little better but it was still semi-clogged for a while. His was bad off.

[IanSzgatti]

i heard citric acid and distilled water are a good flush tool