GP died.

I have a 1999 GP gt with 204,971 miles on it. Had a slight coolant leak coming from the lower intake gasket. Started digging into it and found that the upper intake passages above the EGR pipe were beginning to deteriorate. Went and picked up a Dorman to replace it. Finished lower intake gaskets and installed all components removed. Drove the car to and from work on Monday. (60 miles) Drove to work on Tuesday. I didn't have any issues with these trips. Car has never been run hot. Regular maintenance is kept up. Driving home on Tuesday I started loosing power and a clatter seemed to be coming from the engine. Stopped at the next exit which was less than a 1/4 of a mile. Checked everything. No leaks anywhere. No coolant in oil no oil in coolant. Was about 1/2 qt low so I added oil. Still couldn't get rid of clatter noise. Almost sounded like a lifter tapping. Proceeded home slowly. Stopped at Autozone and had codes read because the light was still on from before the tear down. Listed a MAP code. Replace MAP and the engine locked up. Is not electrical. Have everything back apart with all the plugs out and can hardly spin the engine over with Large ratchet on the crank. Have I stacked a bearing. Is the engine done. Did I do something to cause this. Anyone have a extra engine?

I hate to say it but that is exactly what can happen if you wait too long to do LIM gaskets when it is leaking. You were just unfortunate enough to replace them and then have the engine go out.

Same thing happened to a guy at the shop. A car came in, grand am with 3100, blown LIM gaskets. The guy had still been driving it. The mechanic took it apart, replaced the LIM gaskets, got it back together, got it running, called the owner to pick it up. Owner came later that afternoon, checked the work, left the car idling in the parking lot while he came in to pay the bill, when he got back out, car had stalled. We pulled it into the shop, no compression on 3,4,5,6 cylinders. Tear down we found a siezed cam bearing which caused the camshaft to split right in half. Boy was that guy mad when he found out he needed a new motor.

You did change the oil and filter after replacing the LIM gaskets and UIM manifold, right? What brand oil and filter did you go with? Maybe it dropped oil pressure.

Either way it doesn't matter. Whats done is done. You can try Morads for a used motor. I am sure they have what you need.

http://www.moradpartscompany.com/

It's a long shot but maybe you just have a leak at the throttle body & flooded the intake with coolant. Put a wrench on the crank bolt & see if the crank will rotate in either direction. If it rotates in one direction but not the other then remove the spark plugs & try again.

I hate to say it but that is exactly what can happen if you wait too long to do LIM gaskets when it is leaking.

I agree. The engine should have been properly flushed out to remove all coolant contamination in the crankcase after the LIM and UIM job. You cannot see it visually but it is there. Also, the coolant plays hell with the anti-drain back valve found in a typical oil filter and will cause lifter chatter.

It sounds more like a hydrolock condition. Hopefully it is not too late and there is no camshaft, crankshaft or connecting rod bearing damage.

BTW - Getting a MAP sensor DTC is common when the front bank LIM gaskets are bad whether replaced before or after. Remove the PCV valve and see if there is coolant in that part of the UIM.

if you do work like that again i would suggest putting in royal purple breakin oil it helps prevent that from happening. i haven't had an engine seize since using it and we did the same work on our 01 grand prix 3.2

01 grand prix 3.2

Do you mean 3.8 or 3.1?

sorry yah it's 3.8