Oil pressure after head gaskets

Olds Bravada 1996 185,000 miles

My head gasket went in the truck and I got someone to replace the head gasket. He had the heads milled and has it back together. Now he tells me that my oil pressure is going up and down? What would cause this. I had no problem with oil pressure before the head gaskets.

Any thoughts would be great. I have been without my truck for 6 weeks now and I really need it back. 100+ degrees outside and no air in the car. Help please.

The answer is this;

Not sure what problem is being described here.

It is very possible the oil pressure problem was there before the head gasket change and it wasn’t noticed. Oil pressure does “go up and down” as the engine RPM rises and falls. That is normal. Falling to very low levels at idle is caused by worn engine bearings. Oil pressure jumping around at steady RPM is usually a problem of sticking oil pressure relief valve in the oil pump. That can be caused by trash in the engine getting into the valve. Or it can be caused by wear as well.

I’ll assume you mean your mechanic? Why not ask him what this means?

Did the head gasket failure result in coolant getting in the oil pan?

You need a better description of the problem. Find out how much it goes up and down and how fast it is doing it. Is it related to a change in idle speed? Etc…

On a vehicle that old, what’s happening probably isn’t related to the head gasket. Replacing the head gasket on my car happened to coincide with a failure of the idle air control valve; it was pure coincidence.

Treat the problem as if you didn’t just get a new head gasket.

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Unless I hear otherwise, I’ll assume this vehicle has the 4.3 liter V6

I might ask WHY the head gaskets were replaced . . . ?

If coolant was getting into the crankcase, as @TwinTurbo was alluding to, then the most likely reason was the lower intake gaskets, not the head gaskets. Thus, there’s a good chance the heads shouldn’t have come off in the first case. And in doing so, more opportunities for problems were created . . .

As far as the engine oil pressure . . . has anybody even bothered to hook up a mechanical oil pressure gauge? That way you’ll know if the engine’s healthy, or maybe there’s a problem with the engine oil pressure sensor/switch, the wiring, cluster, etc. . . . ?

And if anybody DID hook up a mechanical oil pressure gauge, tell us the readings . . . for example, what was the reading at idle . . . ? what was the reading at 1000rpm . . . ?