Ok so my mom has a 98 bonneville and i want it she was driving it home one day and it died so she had it towed to a local shop the guy said there was water in the spark plugs so the head gaskets are bad or the head is cracked. from everything ive seen these 3800 dont normally have head gasket or head issues i want to fix the bonne and make it my daily driver it has about 100k on the motor and did run great until this happened the bad part is shes in california and im in nevada so i cant just drive over and take a look at it myself. from the symtoms what would you guy suggest? UIM? LIM? i dont have alot of money so i want to be very educated on this subject before i dive in and make that road trip to fix it and bring it back with me. i am a certified kia/mazda/Subaru mechanic. just not familiar with the bonnevilles. i have a full set of hand tools available where the bonnevillies located. Please any information on this subject would be greatly appreciated i searched alot of the forums but found nothing similar to what im experiencing. Please help!

Pull the throttle body and look at the EGR tube. You will find coolant there. That'* the problem, not the head gaskets.

Wow for the quick response is it a quick fix? How much would it cost to fix and what do I do I need to purchase??

What happened is the plastic is cracked around the EGR tube and there'* coolant ports run right next to it. You can get the gaskets and pull the UIM and plug those coolant ports, you really don't need them. they just warm up the throttle body a bit.

Ok so I'm going to need a new throttle body gasket ,egr elbow, uim gasket and what else?
So since its just that little elbow could coolant have gotten into the motor? Second that elbow being cracked would make it not run? Should I replace the plugs as well?

Not sure what elbow your talking about. The problem is most likely the EGR stove pipe.

Would I replace the whole egr? Or is just the stove pipe able to be replaced? Basically what all do I need and where would I get the parts I need! Thx for your help! BTW nice bonne nice shiny supercharger!

The EGR is fine, it'* the UIM that'* the problem. You see, some mental midget thought it would be a great idea to make the UIM our of plastic, and then run hot exhaust gas threw that with coolant passages right next to it. The plastic get brittle and cracks letting coolant in to the EGR passage. That then allows coolant to get in to the engine.

Cool so where can I get a uim should I replace the lim as well?

This is what you need to fix the problem...



Rockauto.com has this part, and the needed gaskets for $79.