Is it possible for oil to leak from bad intake manifold gasket?

2003 Chevy Impala 3.8, 138k

I have an oil leak coming from the top of the engine and I’m trying to determine if it’s possible for oil to come from a bad intake manifold gasket or if only coolant can come from that? It’s definitely not the intake plenum gasket as there’s no oil around that.

It’s most likely the valve covers but I’m trying to do my due diligence and make sure oil can’t come from a bad intake manifold gasket.

(There’s is no coolant leaks btw)

There’s no reason for oil to be in the intake manifold, as there’s no moving parts.


Ok, so it can’t come from the gasket underneath the intake manifold either?

Thanks for the quick reply btw!

The camshaft is located under the intake manifold, there is oil under the intake manifold, the gaskets on each end of the manifold seal the camshaft valley of the engine.

Gotcha. So oil could definitely come from the gasket under the manifold if it’s bad.

Thanks for the reply

Yes. The underside of the intake manifold on that engine is constantly splashed with oil.

Alrighty, I’ll just do it all then since these factory gaskets are known to suck.


The Chevy 3.4 intake gaskets fail and cause coolant leaks. I think the 3.8 motors had plastic intakes and metal intakes depending on versionS so it’s a bit different. I know the 3.8 had coolant elbow leaks forever.

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You’re absolutely right. Very common issues on the 3.4 and 3.8