How do you replace a intake manifold gasket on a 1999 Pontiac Grand AM?
I'm just finishing this same job on my 1997 Pontiac GrandAm. First of all, this is a known design weakness on these aluminum 60 degree "V" engines.....let me guess, it leaked coolant either to the outside of the engine, or more likely, into the engine where it turned the oil into a chocolate-colored froth.
Secondly, this job is non-trivial....takes a lot of tools, and a bit of know-how.....and you can get into big trouble with crossed, or stripped threads.....I say this because of the manner of the question leads me to believe that you've not done major engine work before...this is not a first-time job.
The general answer to your general question is that you remove the accesories (alternator and power steering pump, vacuum lines, ignition components, throttle linkage, cruise control linkage, MAP sensor, EGR stuff, etc.) and unbolt the intake manifold (upper and lower) sections, remove the old gaskets, clean everything up and reassemble with new gaskets. You need a torque wrench in the inch-pound range for the manifold bolts. Get a manual, and have someone there who is familiar with major engine work, or don't try it.
Best of luck to you
I was having a problem with my intake manifold gasket on my 2003 Pontiac grand am and i took it to a shop it was 600 dollars parts and labor you can get it much cheaper i just chose a mechanic i could trust. now it may not be intake manifold gasket the best way to tell is to lift your oil cap look at the backside of it and if there is a blueish tint liquid on the cap then your getting condensation which means bad intake gasket. But it can also be your thermostat housing messing up which would be much cheaper.