I have a 97 Lumina with the 3.1L engine. It was on the highway the other day and "died". Im not sure exactly what happened as I wasnt driving it. It got towed to my house and when I went to start it, all it does is crank and make an awful noise and throw out a backfire. At first I thought the timing jumped on it, but someone suggested replacing the ignition control module first, as it still sounded like it had suffecient compression. I replaced that today, It started right up for about 30 seconds and ran by itself. anywhere between 500 and 2000 rpm the engine shook like a b*****d but if i got it to 3000 rpm it was smooth. the car then died, and when I tried to restart it, nothing, back to square one with just cranking and backfiring. Any ideas?

Forgot to mention, while it was running for its short 30 seconds, the oil likght was on. I checked the oil and it was full. Also no CEL

Timing chain most likely. Unless extremely lucky will also need to replace pushrods & do valve job, as this is an interference engine.

it could possibly be a blown head gasket these 3.1's are known for popping those! ( from one cylinder to another ) that would cause a healthy back firing situation. not sure why the icm helped maybe it gave it enough spark to ignite the poor mixture as it passes back and forth between the cylinders. the best way to tell if its got a blown head gasket it to do a compression test on each cylinder and if 2 in a row are exactly the same (or very low compression) - bingo - you have a blown head gasket between those two cylinders. also you could take the upper intake manifold off and put your hand over each intake tube as someone else cranks the engine ( with the spark plugs in ) and see if one or more cylinder is pushing air back thru the intake. it should ONLY SUCK your hand down into the intake tube!! it should NOT be pushing air towards you! that would also cause a bad vibration! good luck!!

Only way to determine a bad head gasket on these if it was missing at first.It would be cheaper to find an used engine if the timing chain broke and even worse,a broken cam and the block is junk after this happens after the camshaft breaks.It washes out the cam bearings in the process.You can get an used engine for at least $400.00 to $500.00.If you do the valve job,replacing the timing chain,it would be over $600.00 for for the valve job on both heads and parts (gaskets,timing chain).3100s are known for eating cams since the cam journals in the block were not casted right from the factory in China,casted offset.Jasper found this out and fixed it.Jasper align bores the cam journals and puts in upgraded cam bearings.Jasper is the only one that does this

True the cost of the engine (purchase only) is a little lower, but the labor cost to R&R the engine if you are not set up with a shop, engine hoist, power tools, etc. is a lot higher.

As was mentioned run a compression test and that will tell you if engine has mechanical problems, which it sounds like it does.