1997 Oldsmobile Cutlass Overheats and Blown Engine

Hello. Wow it’s free? Most of these charge money.

Yes we are.

Well just a few questions…car is a 1997 Oldsmobile Cutlass 3.1L 3100. I have a pro GM mechanic of 20 years working on this thing. I bought car 56000 on it last year with really bad coolant in it, oil was great. Had it flushed and after that seemed overheating but we kept using heat to keep it cool or drove it to cool it. Eventually 4 months later the camshaft broke.

Were you getting good heat out of the vents? How hot was the engine running? So new engine from the junkyard lasted 4000 miles same thing broken camshaft. Didn’t seem to overheat this time although this is my question.

What is normal temperature range on that car. Right now 3rd engine. It’s a little less than half way between hot and colds until it sits. Then it goes up about a quarter an inch…thermostat opens, fans comes on and cools it back to half but seems slow going up and slow going down. Is this normal?

Yes heat has always blown hot all 3 engines. Problem is coolant light comes on the second the gauge starts rising past half and goes out when back below half on all 3 engines. Makes me think its overheating…i just put a failsafe thermostat in today and same thing. Temperature rise up to 3/4’s and back to half after a few minutes. Get all that?

The gauge should run at half or a little above to just below half all the time. If it is going to 3/4, then yes it is overheating.

That’s what i said.

Does the high speed fan come on when It gets to 3/4?

Yes the fans come on when its 3/4’s.

If it has new thermostat, no bubbles fully of fluid and hot inside the cab….what is causing the overheating

To be sure, there are 2 fan speeds. Low comes on at about 225 degrees F, and high at about 255 F. Do you have both speeds?

I do not think it came on at the low speed but i am not positive.

Well, that could be a problem. These usually had 2 fans. 1 will come on for low speed, then both at a higher speed.

I know it has two fans…is one for low temp one for high temp? I will check that…next q will that fluctuating temp in coolant caused the camshaft to break twice on two different engines. I’m scared to death I’m going to snap this 3rd camshaft. You have been very helpful BTW this website is awesome!!!!

An overheating engine can cause that to happen. I would get the fans checked out, and also look for a restriction in the radiator. Especially if it gets hotter when driving.

It gets cooler when i drive and the low coolant light goes out. When i stop the car and let it idle temp goes up light comes on then when it gets 3/4s it slowly goes back to half…light stays until til going 60mph a few mins then goes out

Hmm. Low coolant will of course cause overheating, but bubbles in the system will also cause the light. Bubbles are usually caused by a blown head gasket, but unlikely since you have changed engines.

Yep and he bled out the coolant bubble with that bleeder screw thingy so its plum full of coolant…he says its sensor in radiator…but it only comes on when getting hot?

I would have the radiator checked for being restricted. Sometimes can be hard to determine. If your mechanic has a laser thermometer, have him check several areas of the radiator when the engine is hot to see if there are cool spots. This is a sign of a restricted radiator.

So if it was restricted it would trip that light and also cause it to heat up til the fans cooled the engine down or wind from the highway correct?

It does sound like the low coolant level light is just caused by a faulty sensor. But a restricted radiator would give you the overheating conditions you are having. Yes, with more airflow over radiator at higher speeds, this can help out a plugged radiator. And the coolant when we bought it was damn near black.

Ya, that is common with the orange Dexcool antifreeze when it is never been changed. Also leaking intake manifold gaskets or headgaskets will cause that. That can cause the radiator to get restricted.

Ok well the coolant is very very green now, just this stupid problem and 2 broken camshafts…working on the 3rd.

Get the overhating fixed then the new engine and you will be good to go.

You have been absolutely the best! thanks you very very very much bro!