Intake Manifold Leak = ???
 

Hey guys, a buddy has a Chevy Tahoe SUV that has been leaking a small bit of reddish fluid on the garage floor. Seemed more like tranny fluid, but his shop says intake manifold leak causing a mix of coolant and oil.

does this make sense to you guys? I can't see how oil would get into the picture? Head gasket OK, but intake?

your take?


-Chris

It's the Lower intake manifold. The lifter gallery is right under it (where the oil from the top end drains into on it's way to the crankcase.), and the coolant (Dex-Cool) enters from the thermostat housing. The Lower Intake Manifold (LIM) gasket is plastic, with a silicone bead around the ports. They fail on a regular basis.

Fel-Pro makes the best replacement gaskets for GMs. The new Gaskets are steel with a very thick molded silicone area for the seal. I've never seen this new type fail.

Dex-Cool is orange, mix with oil, and you get a dark red liquid.

If you google Dex-Cool you'll get some nasty returns, but GM SWEARS it doesn't have a problem with the gaskets, or the Dex-Cool. But they still recommend using stop leak after the repair. All new GMs have it from the factory.

Dex-Cool turns into nasty, impossible to remove sludge at about 60K miles.

The intake manifold gaskets leak. The repair lasts around 60,000 miles.I just had it done for the second time this spring. Fel-Pro has a gasket replacement kit that is supposed to be a permanent repair.