1991 Cutlass Supreme Leaking Coolant Help GM 3.1L V6
Posted in Ignition Systems | Asked on Aug 14, 2010
Below is the question about 1991 Cutlass Supreme Leaking Coolant Help GM 3.1L V6, I recently bought a 1991 Oldsmobile, Cutlass Supreme and I knew it was leaking coolant at the time but not where, so I bought it thinking it was an easy fix. I pulled the thermostat out and filled the head with coolant to see where it was leaking from and it seems to be coming from around the exhaust manifold and the distributor. Im really worried about a cracked head or head gasket. I know that GM 3.1L V6 engines are notorious foe leaking coolant from the intake manifold, but I dont see why it would be pissing coolant from underneath the car by the manifold. I really need any help anyone can offer! Thanks a lot!!
-Garrett
Edit:
It seems to be between the dist. and the exhaust manifold, im not too sure. Its coming fast though and its really hard to see. Im pulling the exhaust manifold off tomorrow to get a better look.
General Motors 3.1 Liter V6 F1.
There are 6 Answers for "1991 Cutlass Supreme Leaking Coolant Help GM 3.1L V6"
It’s probably still the lower intake manifold gasket. It can leak from there and look like it it coming from where you are seeing. the gaskets on the 3.1 run a good way down the center of the engine.
That car has aluminum heads so if was overheated enough times or badly enough you may have a cylinder head that has cracked.
I have never had one of these engines that did not develop a leak in the head or gasket and eventually burn up. That is about 5 of them. You will have to do what I tried to get around every time – pull the top end, replace the gaskets, and have the heads checked for cracks. And did you say near the distributor?
That’s the exact same engine as my 91 Firebird.
It’s one of the better engines in the L series. It sounds like the head gasket seal is blown on the intake manifold like you fear.
Plan on a full weekend to replace it. This is assuming no cracks in the manifold or the heads. I am assuming the Cutlass is rear wheel drive and fuel injected.
If you have some common mechanical knowledge, the throttle body and fuel injector rails will have to come off. Then the bolts on the Intake manifold, rocker arm covers, and a few head bolts to release the Intake Manifold. If you’re not familiar with engine repair or comfortable, see your local mechanic. Hayne’s manuals (In auto parts stores) can help you on the specific steps for this repair.
You can get the head gasket kit with everything you need. Be sure to use lock tight on the bolts when you put it back together and proper torque in sequence on the bolts. This is important so nothing vibrates out or gets warped.
I didn’t think this engine had a distributor. If it’s like others I’ve seen, look for a leaking heater hose tube connector under the throttle body. The originals were made of zinc, which degrades over time to the consistency of cheddar. They are very tough to remove because they simply crumble, leaving the threaded portion behind. You might be better off to replace the coolant manifold that it screws into.
Try again.
What dizzy on a 3.1L? They never had one in the FWD cars.