1990 2.5L Grand Am major problem

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.

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?

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.

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

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

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.

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

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

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.

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.

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?

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.

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

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

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

I should be able to get a gauge. A friend and I have changed the timing chain on this car once before when the chain tensioner chipped a hole in the timing chain cover so I know there's a chain there. That's been a long time ago though so I don't doubt something could have gone wrong since then.

Hope i'm not too late to chime in.

Your accessories are driven from the crank pulley via v-belts, they will turn when your starter is running unless you sheared your crankshaft in half, very unlikely.

The most likely culprit is the crank sensor located behind the ignition module on the back of the motor where the ignition coils are. First thing is to see if you have spark, pull a plug wire and have someone turn it over..there should be a spark jumping out of the boot to the plug.

No spark...either module or sensor, I suspect sensor. Zip tie the wires on each coil together...two per tie, makes it easier to put back...doesn't matter which terminal as long as 1-4 & 2&3 are together on the same coil.

disconnect neg cable
13MM deepwell and standard and possibly a 10MM socket...sorry been a while. Fairly easy to remove just takes patience. Remove the aluminum plate with the coils intact and when all the bolts are out (3 I believe), pull it slowly from the block since the sensor is inside the block and takes a tug to work past the rubber seal.

Once removed you will see the sensor and it's two very small bolts holding it in, replace and reinstall.

Now, if that's not the case you at least have a lesson on if the motor dies abruptly with no warning and will restart when it cools..ask me how I know.

Now if you are observing very minimal compression you may have the old fiber gears for the camshaft and they may have broke. You can replace the gears or chain with motor in car but you need to remove the oil pan first.

If that's the case, send me an e-mail and i'll try to help.

Thankx for the input I6pwr, but if you read the 1st page he doesnt have any noticeable compression.

Which is most likly the timing chain broke agian.

and Welcome to AF I6pwr !

Yeah I know but he said all the rockers are moving.

I guess the only way to realy find out is pulling off the timing chain cover and going from there.

I have seen rockers move on v6's when the fiber gear broke. Most newer engines use metal gears, which last much longer then those old fiber gears.

Hopefully he'll post back when he figures it all out.....

I can't remember when GM switched to the chain, was sometime in 89 if I remember but I don't know what the cutoff month was, I know mine has a chain and it's a 90'.

I was wondering where to go next. I've got a spare car so fixing this has taken a back seat to work and kid running around. I know it's a chain from the last time I had to change it. The small gear came with the new chain last time but I don't know what it was made of. I'll definitely keep you all updated when I get the timing chain cover off.

Was the engine making alot of racket near the cover before it stopped running?

Mine started to rattle a bit around 100K so I changed the chain/sprockets and tensioner. About 175K I lost my force balancer and maybe related maybe not, but a piece of my tensioner broke and may have caused the failure of the force balancer...dunno but I replaced the balancer/timing guts again and she's still quiet.

If it's not the fiber gears of years before I feel the tensioner could have been built somewhat better but hopefully you get it all squared away. Before you tackle the job...go get yourself a 12 point 8MM wrench, one of those cover bolts are really in a bad spot and the 12pt box end is a lifesaver with it's short swing.

I finally got around to working on my poor baby. I got everything off except the crank shaft pulley. There is a 24mm bolt it looks like but I didn't have a big enough socket to tackle it last night so I'm bringing one home tonight.

Do I need any special tool to make the pulley stop turning? Is there a special tool for removing the pulley as well? I work in a pawn shop so I should be able to dig up all of the tools I need. I'm just not sure what I need!

Double post, sorry.

I have one more little bugger bolt that's in a hard spot on the timing chain cover but I noticed that I can see the timing chain from where I removed the oil pan. It appears intact and is rotating when I turn the crankshaft pulley bolt. It's been a lot of taking apart to get this far so I'm going to probably change the chain regardless. I just don't know what to do from here. I guess I'll have to get it all back together and actually find a compression gauge. Maybe I didn't do the finger test right or something.

Quick question. Should the timing gear marks both be at the 6 o'clock position or should the crank be at 12 and the cam be at 6? I'm trying to get the chain off but the Chilton's book looks like the marks should be at 6 for the cam and 12 for the crank gear but when I got the cover off, both were at 6 when I lined them up.

yes i believe crank = 12 & cam at 6 o'clock the 2 dots should match up with each other but if you are 180 degrees off turn crank one revolution & they'll match up
so sounds like the chain is not you problem

Man, it sure sounds like he didn't do enough troubleshooting before ripping into the engine to replace the timing chain.


Did he ever determine if it's getting a good spark?
What about enough fuel pressure??
Is the throttle body spraying fuel?Let's see what it ends up being, probably not the timing chain.:sunglasse

You're right, I am a rookie when it comes to working on cars. I do appreciate all of the help you guys give though.

make sure but if its dead on start putting back together.your call on replacing they're a year old right & if their metal chain is good n tight so your call on replacing chain/gears but definitely new seal & gasket.!!!then start with the basics checking for good spark,fuel.Good Luck

If the chain is broke, the rockers will not move. You can check for play in the chain, in most applications, by removing the distributor cap and watching the shaft movement in older cars or by watching the rockers in newer cars. You do this by setting the crank pully at top dead center. Then you watche the dist. shaft or a rocker arm while turning the crank pulley in the opposite direction you originally turned it to get to TDC. As you turn the crank pulley, watch for the first sign of movement in the shaft/rocker and stop turning immediately. Then check the crank timing marks, or measure the distance for comparrison if turning away from TDC. This reading in degrees should not exceed 6 degrees. If it does then the timing components need repair/replaced. If neither the shaft/rockers move then either a chain or gear is broken/stripped of teeth (common with nylon gears).

You can also do a compression test to see if a chain is broken as some of the valves will stay open and give zero readings.

The chain was intact but was very sloppy. There is a dampener inside that is made of nylon with a metal spring and it was destroyed. I should have a new dampener today. I just wanted to make sure I wasn't putting the new chain on with the gears improperly aligned because the Chilton's book has the alignment marks in a different spot than what I saw when I took them off.

Finished with the chain and it still won't start. I pulled a wire from 2 plugs, 1 from each coil, and I'm getting spark. I can smell fuel when it turns over. Any ideas on what I should check next?

It sounds more like a split sidewall to me, Have you checked for water in your oil, and viceversa?

The oil didn't have any water in it. I'll drain the water and check it.

Thats a good sign. Have you done a compression check on all of your cylinders? Does your oil smell like it has some gas in it?

I didn't notice any gas smell when I drained the oil, just when I was trying to start the engine after I put everything back together. I got a compression gauge from work today and will check it soon.

I'm in the neighborhood of where Hurricane Ike is headed though so I've got some other things to wrap up for the next couple of days. Maybe my carport will fall on it and I can claim it on my homeowner's insurance!

well, so far, it sounds good. If you were to blow a hole in a piston, or split a cylinder wall, the engine would probably still run, but like $#!t, and probably not for long.