I have a 1995 SLE and Have confirmed coolant on the plugs. It ran really bad and smoked alot. Was the smoking caused by the coolant thinning the oil ? THe engine was replaced 1000 miles ago was a donor from a 2001 GP.The motor only has 63000 miles. They should have replace the intake gaskets.. My question is should I pull the pan and check the rod bearings or has more damage occured than that etc. such as rings... Or should I just replace the IMG and change the plugs and pray that it is ok? Thanks. :?:

DO NOT RUN IT ANYMORE!!

Drain the oil. Remove the UIM and insepct the EGR passage. If there is a hole, replace the UIM (possible with a Bill Buttermore sleeved unit, pm him for details). If there is no hole in the wall of the UIM EGR passage, replace the LIM gaskets with aluminum gaskets from GM. Maybe do them regardless of UIM condition. Have all the Dex-Cool flushed out and put the green stuff back in.

Whato do about bearings? I don't know. But you do need to get the coolant laced oil out immediatly.

Well first of all, you give an awful lot of credit to whoever swapped your engine in to assume that they changed the intake gaskets. It would be likely more accurate to assume that they didn't. So on to the questions.

How long has it been doing this smoking?

The smoke is whitish, I assume? If so, it is the coolant burning off.

Has the car sat for very long with this condition?

OK, now onto the should do list:

- change the oil and filter asap.
- buy a set of the aluminum LIM gaskets from an online vendor such as Intense or ZZP or from a local Pontiac dealer
- read the whole of article #38 in TECHINFO above. It has almost all you need to know about this common failure mode. Here'* the link to save you time: 95-03 Upper Intake Failure Information
- Come out of your denial...lol

Bottom line...You may or may not have further issues depending upon the answers to the questions above. Let'* move forward.

That'* Bob Dillon that sleeves UIMs. PM him if interested. I can sell you a sleeve to repair your own UIM with JB weld for $5, or sell you a shielded stovepipe (only recommended for UIMs in new or like new condition). My first recommendation for UIM failure is to replace with the APN factory-sleeved unit. The APN site is linked in the Techinfo article cited by Lash above.

Bob, Bill, Dillon, Billon... whatever....

Thanks for the quick reply to my post. I got all the plugs out and drained the oil last week. I cranked it over and it shot out oil mixed with coolant out the cylinders. my gut tells me to drop the pan and check the rod bearings. If they are really bad and the crank is messed up I think I will stop there. I do not want to keep throwing money at the top end if the crank is shot. I only heard the car run for about 2 minutes. I purchased it for a good price figured it was well worth the fix.. It only has 72000 miles on the car. It smoked really bad white and blue and ran on a few cylinders. If you put the idle up some it would knock some... Could be from running on maybe 3 cylinders and having water in the oil. Rod bearings if I am lucky might be ok, but I do not have any experience with this motor. Any suggestions are greatly appreciated.. Thanks

I think you are on the right track. Drop the pan, grab on to the connecting rod ends and see if there is any radial play on any of them. You might want to pull a cap and examine the bearing shell for evidence of coolant contamination or degradation. If you have a bad rod bearing, the engine will need to come out so you can install a crank kit ($200), and have a shop check and recondition all your connecting rods ($80-$150). All the oil passages will need to be cleaned (best to hot-tank the block ($50) and disassemble and clean all the lifters. If damage was done to the other bearings, for the cam and balance shaft, they will need to be changed out too ($100) Add another $200 for the UIM/LIM work, and another $200 for the oil pan, head gaskets, and crank and valve cover seals, and you've got $850 in it. It is usually cheaper to buy a good junkyard engine, do the LIM/UIM repair on it and run with that.

The $850 is toward the worst case scenario. Many have done the UIM/LIM work and found the bearings to be OK. Others have suffered bearing failures shortly after repairing the top end. That is why we try to encourage owners to do the UIM/LIM repair BEFORE an internal coolant leak develops. One good thing is if you do the UIM/LIM work and find the bearings go bad shortly thereafter, the LIM gaskets, new UIM and gasket and even the coolant elbow can be re-used on a junkyard engine. When I do the UIM/LIM work, I go very sparingly on rtv on the LIM only applying a small dab in the corners where the two pieces meet and none on the end rail seals. This results in a tiny oil seep over several years, but makes the parts removable if they need to be re-used.

I finally pulled the pan and the motor threw a rod. Pieces is the pan and broken crank pieces. I guess it is time to visit the bone yard for a 3.8... Does anyone have the motor removal and install procedure for bonneville engine? If not I guess I will try to find a chilton manual. Thanks for all of your help.

Chilton'* 28200 is the one you want. Techinfo has a procedure for pulling the engine with the trans, but not for the engine alone. You will find the wiring harness can be disconnected at the firewall, saving you the effort of stripping the thing off the engine in the car. I would strongly advise that you replace the crankshaft rear seal before installing the new engine. If it were to fail, you would need to separate the motor and trans again to replace it (voice of sad experience).

So am I correct in saying that the APN UIM has the metal sleeve and the Dorman does not? :?