Just as some history to this post:

I have a 1997 Grand Prix GT.

In December 2007 (@215,000KM), the GM dealership I typically take my car to advised me that I had an antifreeze leak, and that it was the intake gaskets that were leaking. (Needless to say - in reading some of the posts at this site I'm surprised that at the time there was likely a class action law suite going for this very problem). I knew I was leaking coolant, because I had to add coolant every few months.

I've had numerous repairs done on this car and in 2007, it was starting to cost me more to keep the car running that what it was really worth. I declined getting the intake manifold gaskets replaced, since the antifreeze was leaking externally, not internally into the oil. I was of the opinion that my money would be better spent towards another vehicle.

Fast forward to March of this year, and after more than a year without having to perform any major repairs, I decided it was time to do the leaking intake gaskets. I did some online reading, picked up a chilton - and after spending some time deciding if I could tackle the job myself - I opted to take it to the dealership and let the "professionals" do the job. It's our only vehicle, and I had some significant doubts in my abilities to get this done without causing me a major problem.

This work was performed at 235,000 KM.

On May 8th while driving on the highway and going up a valley, my speed started to drop. I thought it was pretty odd since I've made the trip frequently in the past and the car has never had a problem climbing the hill. I put my foot on the gas and noticed it was all the way to the floor. At the top of the hill I tapped the brake to disengage the cruise and the engine died. Once I coasted the side of the road and came to a stop I tried to start the car, and although it would run, it had a significant knock and would not idle on it's own.

Checking the oil revealed a very dark/muddy looking oil with a lot of metalic in it. I had the car towed home.

I've sent an oil sample off for analysis and received my results today.

Here's the comments from the results:

Suggest inspecting this unit for EXCESSIVE WEAR; Suggest inspecting cooling system (head gasket, heads, seals etc for leaks. Coolant indicators
(Sodium, Potassium) are at a SEVERE LEVEL; Suggest flushing system; Cylinder region metals (pistons, rings, liners etc.) are at a SEVERE LEVEL;
Bearing metal is at a SEVERE LEVEL; Water is at a MODERATE LEVEL; FUEL DILUTION is at a MINOR LEVEL; Viscosity invalid due to water
contamination;
I suspect that it's the intake that I had fixed which is leaking antifreeze into the oil. I've put about 3,000km on since the intake was done.

Oddly enough the dealership called me a couple weeks ago to have me bring my car in for a "spark plug wire recall". I told the service advisor at that time the problems I had, what I suspected was the problem and that I was waiting for an oil analysis to come back to confirm my suspicions. They told me to let them know what the results are.

I know it's also possible that the heads/head gasket could also be causing this, and I'm wondering if there's an easy way to determine if it's one or the other (heads vs intake) without investing a lot of money into this vehicle. I'm hesitant in taking the vehicle back to the dealership for them to determine that because I suspect that they will be doing what's in their best interests, not mine in trying to determine the root cause.

Any suggestions? I'm a little choked over this whole experience. I put $1200 (also had the brakes done -with ceramic pads no less- ) into this car in March, and get 3000km for it. I suspect that had I not taken it in to get "repaired" that I'd still be driving it.