Coolant in air intake

[Jon Boy]

My wife's 93 Buick Regal 3.8 has slowly been losing coolant for a while, and I've occasionally noticed some white smoke coming from the tailpipe. The other day I was checking the air filter and noticed a little bit of coolant in the intake housing and duct. Does this sound like a leaking intake manifold? I've never done one before, so I'm not sure what the symptoms are. Any help would be greatly appreciated.

[xtremerevolution]

My wife's 93 Buick Regal 3.8 has slowly been losing coolant for a while, and I've occasionally noticed some white smoke coming from the tailpipe. The other day I was checking the air filter and noticed a little bit of coolant in the intake housing and duct. Does this sound like a leaking intake manifold? I've never done one before, so I'm not sure what the symptoms are. Any help would be greatly appreciated.

 

Three possibilities. The least likely is a leaking LIM gasket, where reversion may push coolant back up into the intakes. The more likely is a leaking throttle body gasket. The most likely is a leaking upper intake manifold plenum o-ring at the throttle body coolant passages. I would personally replace the latter two and go from there. Its a very easy job and can be done in 30 minutes if you've done it before, or 2 hours if you haven't. Where are you located?

[Jon Boy]

Thanks for the advice. It's a good thing I asked before I tore into the intake manifold. And I live a little ways south of Salt Lake City, Utah, so that's probably too far for you to come lend a hand.

 

And I should've mentioned this earlier: for a while now we've been getting a little bit of oil in the coolant overflow tank. I thought it was probably tranny fluid leaking from the cooler in the radiator, so I replaced it with one from a junker, along with the hoses and thermostat. It looks like there's still a little bit of oil in the tank, but I don't know if it's new stuff leaking in or old stuff working its way into the tank. I don't know if that's in any way connected, but I suppose if there's oil in the coolant, it could be degrading the gaskets or o-rings.