I have a 1999 Lumina with a 3.1. It has 175,000 miles. It recently ran hot while my wife was driving it. I checked it and it had an external leak from the intake manifold gasket. I checked the compression and each cylinder has 160 - 165 lbs. So I replaced the intake manifold gasket. Now it is leaking water and oil mix in the EGR. When I turn the engine off I can see steam and hear water dripping into the exhause line going to the EGR. I pull the EGR off and it has oil/water mix in it.

Any thoughts out there as to what might be wrong?

 

blown head gasket, it more than likely happened when it overheated, if you decide to change the headgaskets yourself, then u need to buy new head bolts, as they stretch when torqued

 

Thanks for the info. Any idea what are the chances that the head is OK?

 

if you dont have a strait edge buy one and lay it on the head and look for light behind it, and do the same with the block if the block is warped it may be time for a new engine, the 3.1s are fairly cheap, and would be much cheaper than a rebuild, make sure the head and cyl deck is cleaned up before checking, be meticulous with being clean too, dont need gasket material getting in the cyl