Okay here's one for the history books. I've owned a 94 Cutlass Supreme for 4-1/2 years, 3.1 liter V-6, had 116,000 miles, never had any trouble except for an alternator and starter, and clogged injectors. So I sell it to some people, they owned the car a whopping 8 days and call me to say the motor has "locked up" on them. Are you kidding me? They supposedly went in for groceries, the car had been running fine to that point. Come back out to go home, the car had trouble starting, then started, then had severe rattling noise, then died. The guy said he put a wrench on the crank and could not turn it over. They towed it and had a mechanic remove the starter in case it was binding the motor, no dice, he said it had a broken cam, or such, that the 3.1 liter engines were notorious for broken camshafts. I'm floored over this whole clusterfazoola. Has anyone else ever seen anything like this, esp when the car was running fine and then turned back on with a problem of this magnitude on these 3.1 liter engines? Help is greatly appreciated!

That's unfortunate.

How much damage did the broken camshaft do?

I haven't been able to find out yet, but I can't imagine there being major engine damage from a car that was running fine, shut off for the time to shop for groceries, come out, start up and rattle around then shut off, and then the engine supposedly locked up. At low RPM's and a cool engine, if it had oil and water, I find it nearly impossible that it would be locked up or have sustained "major engine damage." I'm not sure if the new owners are trying to con me into a refund of some sort or not, that seems more likely than their story about my former car.

I haven't been able to find out yet, but I can't imagine there being major engine damage from a car that was running fine, shut off for the time to shop for groceries, come out, start up and rattle around then shut off, and then the engine supposedly locked up. At low RPM's and a cool engine, if it had oil and water, I find it nearly impossible that it would be locked up or have sustained "major engine damage." I'm not sure if the new owners are trying to con me into a refund of some sort or not, that seems more likely than their story about my former car.
Broken cam, valves hit the pistons.

Broken cam, valves hit the pistons.

Yeah, duh, I think I got that figured out, the real question is how does a camshaft break when a car is just started up, after I've have virtually no problem with this car for 4.5 years, the new owners have it 8 days and the motor is locked up. A broken cam is highly unlikely, they've been making cams for 150 years and this would seem to be a very low probability as to the cause. But then this was a "guess" by some mechanic who may or may not be on the mark. Only time will tell when we get it torn down.

ask them if they did anything to the car, changed the oil added any fluids etc. Also make sure they didn't somehow bust the oil pan by driving over something. I understand that they may not be honest with you if they were at fault.

Yes, good point and I did ask the owner, or the owner's boyfriend. He claims that fluids were at their proper levels. I still have trouble believing this is a malfunction that is not an operator error. If it turns out that a cam, or timing chain is busted it will be a one in a million shot that I could have sold the car 8 days before it happened, after owning the car from Oct. 11, 2000 to June 3, 2006 and the engine craters on June 11, 2006.

Yes, good point and I did ask the owner, or the owner's boyfriend. He claims that fluids were at their proper levels. I still have trouble believing this is a malfunction that is not an operator error. If it turns out that a cam, or timing chain is busted it will be a one in a million shot that I could have sold the car 8 days before it happened, after owning the car from Oct. 11, 2000 to June 3, 2006 and the engine craters on June 11, 2006.
These cams have been know to break ,the are hollow designed and this has been somewhat of a problem, it can be exascerbated by the cam seizing in the cam bearings also. Only way a driver could cause this is by ignoring maintenace and causing a lube system failure. You asked in you original post how it sustained major damage, so what was the " duh" about?

I could be wrong but somthing smells fishy...

in my famly we have 4 of these 3100's,, two of them have WELL over
200,000 miles, all running as strong as the day they bought them, not a
major problem yet......

Sorry to Maxwedge, the "duh" meant I know if cam fails it'll drive the pistons into the valves making the engine toast. I'm just looking for info as to the history of these engines. I spoke to the mechanic today who says the 3.1's and 3.8 engines are "weak" and can break in the lower end, I guess the crank or rods, but I certainly don't hear that much about these engines just up and cratering like this. He said he pulled the plugs, put transmission oil in the cylinders to try and unseize the engine and no good, it's locked up, and according to him, will need a total replacement. Then he advises the owners to put a factory reconditioned long block in for $3000 incl parts and labor. In a car that cost them $2900? Duh to that for sure! I still have a hard time believing that I owned the car for nearly 5 years with no trouble at all, they've had it 8 days and it's totaled under the hood. I still think something is wrong with this picture.

I could be wrong but somthing smells fishy........

Well, I just offered to return a goodly sum to the new owners to help repair the cratered Cutlass. That's all I'm going to do, it's just bad luck (theirs), or that's what I'm going to chalk it up to, and not look back, I'm flushing this turd of a deal, and will still go on thinking if I owned the car today it'd be purring like a kitten. End of deal.

Sorry to Maxwedge, the "duh" meant I know if cam fails it'll drive the pistons into the valves making the engine toast. I'm just looking for info as to the history of these engines. I spoke to the mechanic today who says the 3.1's and 3.8 engines are "weak" and can break in the lower end, I guess the crank or rods, but I certainly don't hear that much about these engines just up and cratering like this. He said he pulled the plugs, put transmission oil in the cylinders to try and unseize the engine and no good, it's locked up, and according to him, will need a total replacement. Then he advises the owners to put a factory reconditioned long block in for $3000 incl parts and labor. In a car that cost them $2900? Duh to that for sure! I still have a hard time believing that I owned the car for nearly 5 years with no trouble at all, they've had it 8 days and it's totaled under the hood. I still think something is wrong with this picture.
Seconded on there is a "piece of the puzzle" missing here, neither the 3100 or the 3800 have lower end issues, intake leaks maybe and very occasional cam failure, usually from the bearings, on the the 3100's.

It very well could be a cam failure. I will post the end result if and when I hear how this saga plays out. Being that I'm contributing to the repair cost, I certainly hope to learn the cause of failure. And I agree, lower end issues do not seem to be all that problematic on 3.1 or 3.8s. I have a 3.8 in an 95 LSS 88, and it's a very good engine, knock on wood, with 142,000 miles and still cranking strong.

The Cutlass suffered some sort of damage caused by a valve seat on the head that came loose and dropped on top of the piston and eventually locked up the engine. It was not a broken cam as one idiot mechanic thought. Had these new owners taken my advice, they would have had a mechanic pull the heads and try to figure out what happened before deciding to drop a rebuilt engine in. As it turned out, all that was needed was a new head and a piston and they would have been up and running. As it turned out they put a rebuilt long block in from Autozone and that engine was bad also so the guy ended up pulling that one and putting in a second engine from Autozone. It appears that this fiasco is finally over, but a good lesson learned, always diagnois the problem fully before making a decision that may not be the right solution. A head change and piston replacement would have been less costly than the route they took for sure.

Does anyone know exactly how the 3.1 engine heads are made up, that allows a valve ring seat to break off and drop into the cylinder?

Thanks to all!

The 2.8, 3.1 and 3.4 all have pretty much the same head. Aluminum with pressed-in valve seats. I have handled thousands of these heads in the past several years and have seen many with broken valve seats and the combustion chamber and piston chewed up by the pieces bouncing around in the cylinder. I have also seen the blocks with broken camshafts. These blocks are often junked out because of the cam bore.
Where I work we are throwing the heads away because of overstock from the blocks junking out.