1990 2.5L Grand Am major problem

[AZCS-B]

I was driving to work today and my car just died. It tries to start but it sounds like the flywheel is just free-spinning. I caught a ride to work so I haven't had a chance to have someone turn it over for me while I look around yet.

It's so old that I really don't want to sink a lot of money in it so whatever repairs are necessary I'll try to do myself. I just don't know where to go next because the failure was so sudden.

[AZCS-B]

I finally got it home and had my wife turn it over while I was watching. The starter engages and all the accessories turn but the engine isn't turning over. Does that sound like a broken timing chain?

[xeroinfinity]

If your acessories are turning, alternator, power steering pump, then it sounds like its turning over.... but it does sound like maybe your timing chain could have broke.

About how many miles are on this GA ??

Have you tried pulling a spark plug or two ?

Try pulling one out, place your finger over the hole and have someone turn it over, it should push enough air to pop your finger off the hole. Or a compression gauge would work if you have one.

Just watch out for the plug wires, try not to get bit!

You can also pull the valve cover off and see if the valves and stuff are moving up and down when cranking. If not then your chain is broke.

[Will Help]

Rare thing, you could have broken a cam shaft or sheared a key on the cam gear.

[AZCS-B]

So pulling the timing chain is probably where I should go first then.

[Will Help]

No sir. Remove the valve cover and then crank the engine over. This way you can see if all the rockers/valves are moving or not. This will determine how far you may or may not have to go to make your repairs. Valve cover gasket is cheap and would have to be purchased anyway if the cam comes out.

[AZCS-B]

Thanks! I'll check that after work today and post an update.

[AZCS-B]

All of the rockers are moving when I turn it over. So now where?

[grfnkl]

Did you get a check engine light or any other service lights before the car died? If so you could try to pull a code and see if anything comes back. the 2.5 is a pretty simple engine. My guess is either your fuel pump crapped out, or maybe ignition module.

[AZCS-B]

I didn't get any kind of lights. It just died. And when I tried to restart it just kept turning over and over with nothing happening. But it seems a little weak, like there isn't any resistance.

I'll try removing a plug this evening as Xero suggested.

[AZCS-B]

I pulled one of the plugs and didn't get any noticable compression. It sounds like the flywheel is spinning but nothing is happening.

I'm not sure exactly how everything is connected but without compression and with rocker/lifter movement, how can the crankshaft be turning and moving the camshaft for the rocker movement?

[Will Help]

Only plausible explanation is that your timing slipped far enough to allow piston/valve contact and your valves are bent and not allowing the compression to build due to leakage past the valve heads. There is no other explanation as to why the valves would be held open.

Compression should not be less than 100 lbs in any one cylinder and no cylinder should be 15 lbs or more below any other cylinder.

I forsee a cylinder head removal in your immediate future.

[xeroinfinity]

I would agree!
These engines valves do hit the pistons if the timing chain breaks when the engine is running.

Not to difficult to replace/rebuild the head, probly run around $250-350 for a valve job and milled might be cheaper if you lived further east.

Good Luck

[AZCS-B]

So I probably have 2 problems? Should I pull the head off or check the timing chain first?

[inafogg]

Hello AZCS,Did u use a compression guage??if not try to borrow/rent one.did u check more than the 1 cylinder??this engine uses a gear to gear set up so it does'nt have a chain.now i'm not positive but i dont think they are an interference engine which is good for u if thats right.i'd recheck compression using a guage then let us no.Good Luck