Hey everyone...
Just got the engine (3.1L) torn down in my friends Olds Cutlass Supreme, and I had some questions.

First of all, the cause of his problem was overheating (radiator fans stopped working). The car still ran (not the best, but it ran), but coolant was getting into the oil. I thought right away...headgasket. However, there was no white smoke coming out with the exhaust...

I drained out about 12 quarts of milky oil/coolant mix of the engine...and about a half gallon of coolant out of the radiator.

Today I got it all apart (heads off) and took a look at the head gaskets. They didn't look bad (well anything noticeable), but I could be wrong. I plan on taking the heads down and having them checked out.

Am I right in assuming that a bad headgasket started all of this? If not, what else could be the problem? I just want to make sure that new headgaskets will solve the problem?

Thanks for the help

I had the same thing happen to my 90 3.1 and ended up replacing both heads, I would suggest taking them to a auto parts store with a machine shop and have the heads checked and rebuilt.

I had the same thing happen to my 90 3.1 and ended up replacing both heads, I would suggest taking them to a auto parts store with a machine shop and have the heads checked and rebuilt.

Yep, tomorrow they are both going down to a head shop to get checked out (pressure tested, etc). I'm afraid of what I might find out with the heads because the gaskets looked okay. Possible cracked head?

Time will tell.

I also have to find out where the fan switch is located (there are a few different coolant sensors) and get that checked out. I hot wired the fans to rule them out, so they work. The fan relays were replaced, so they should be good. I just have to check the fan switch, but I can't find any corresponding wire colors from the wiring schematics I have. I might just start another thread on it.

Thanks for the reply

Im doing head gaskets currently, But cant figure out how to get the bracket of that hold the pass front uppser mount in place.

The "fan switches" or relays should be located on the passenger side front fender wall. The sensor itself, should be located just below the thermostat

The "fan switches" or relays should be located on the passenger side front fender wall. The sensor itself, should be located just below the thermostat

Yes, I meant the sensor itself...I wasn't sure of its location. Thanks for the help. Now I can figure out if that is what is causing the problems with the fans.

Thanks

Actually I don't think the head gaskets caused the problem they may have been damaged from overheating however. The primary cause was the intake manifold gasket going bad. The gasket allowed water to get into the lifter galley and then into the oil, hence the 12 quarts of water and oil. Since you have the heads off it is a good time to do the work you mentioned as far as making sure they are flat also you may want to consider a good valve job along with new seals. As for reinstallation, make sure you use new head bolts as these are torque to yield and they should not be reused.

Actually I don't think the head gaskets caused the problem they may have been damaged from overheating however. The primary cause was the intake manifold gasket going bad. The gasket allowed water to get into the lifter galley and then into the oil, hence the 12 quarts of water and oil. Since you have the heads off it is a good time to do the work you mentioned as far as making sure they are flat also you may want to consider a good valve job along with new seals. As for reinstallation, make sure you use new head bolts as these are torque to yield and they should not be reused.


The heads are off at the shop and they are going to do a pressure check on them and resurface them (also remove a couple exhuast manifold bolts that were broke off). I didn't think the head gasket was at fault after taking it apart. I thought maybe the manifold gasket might have been the problem, but I wasn't sure. It makes sense though.

I should use new head bolts? I wasn't sure of this. I know on another car I worked on, the manual said to use new bolts, but from looking in the manual for this car, nothing was mentioned about new head bolts.

Thanks for the help

use new bolts. The old ones strech and will not torque properly. Im still in the middle of my head gasket change yet still cant get the damn mount off the pass side front!