>As I mentioned in my last post, I was driving home two weeks ago and the engine in my 2002 Grand Am stopped on the interstate. I got it towed home, and I’ve been trying to figure out what’s wrong with it. I turn the key, and it cranks, but doesn’t fire. It sounds just like it would if it were out of gas. I know it’s not the fuel pump, because I sprayed starter fluid into the intake, and it doesn’t start. I tested, and I have spark present on all four cylinders. Given all that, I assumed it was a busted timing chain, so I’ve been taking the thing apart to get to the timing chain.

I’ve been going through the Haynes manual diagnostic, and it told me to do a “compression test.” I did the “cold” compression test (since the car won’t start), which showed 50 psi in the first cylinder, 100 in the 2nd, and 0 in the 3rd and 4th cylinders. Since I also found oil in cylinder #4, this makes me wonder if the head gasket blew, but there was no coolant in the oil (which I drained) and there was no smoke while the engine was running (both signs of a blown head gasket). The guy at Advance Auto thought it might be a busted crankshaft, and he told me to put straws in the spark plug holes and crank it, which I did. He said, if the straws don’t move, that’s your problem. All four straws moved, so it’s not the crankshaft.

As I see it, there are four possible options:

1. Broken timing chain. But does this answer the question of why there’s no compression in cylinders three and four?

2. Blown head gasket. But would this keep the engine from starting at all, or just make it run really rough?

3. Busted piston rings on cylinders 3 and 4. But again, why would both go out at the same time?

4. Some other problem (cracked block maybe?).

Anybody have any ideas of any other tests I can do before I have it towed to a repair shop? My other alternative is to junk it and go buy an el cheapo car (like $500-$1000).

Thoughts?