Intake Manifold Leak = ???

[cbeers]

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

[lm6y]

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.

[dhoward]

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

[Brian 162]

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.