91 325i e30 convertible automatic,timing belt change, starting + noise problems

[BANSHI]

Timing belt broke causing valves to bend and break rocker arm. recently replaced timing belt as well as the cylinder head valves and rocker arm that broke. When lining timing marks up they were almost perfect except for top cam mark was off by half a tooth, I tried getting it spot on relentlessly, never got it. Put everything back together and started it up. It starts just fine then a few seconds later coughs, bogs down then dies unless you rev it keeping it from completely turing off. Idle is shaky in the 1200 to 500 rpm range till warmed up and stays at a 740 rpm then the car runs okay. The smell of gas is strong, as well as the new spark plug tips are all yellow now, meaning a misfiring problem. Also there is a loud sewing machine like tick sound that gets faster and louder when speeding up. I did a valve adjustment three times to .010 in and it never decreased the sound.

[vpilarrt]

Did you replace all of the valves or just the ones that appeared bad? One/some could be bent enough to be a problem but not enough to appear bad/bent.

[jalopi]

Could be the valve timing (since it was off a half tooth) or another bent valve.. but i'm going to go with valve timing. Did you rotate the crank by hand twice after the belt install to see if the marks still line up?

Also, the sewing machine noise should be the valve adjustment, did you adjust them cold, hot or what?

[Mr. Tasty]

Timing belt broke causing valves to bend and break rocker arm. recently replaced timing belt as well as the cylinder head valves and rocker arm that broke. When lining timing marks up they were almost perfect except for top cam mark was off by half a tooth, I tried getting it spot on relentlessly, never got it. Put everything back together and started it up. It starts just fine then a few seconds later coughs, bogs down then dies unless you rev it keeping it from completely turing off. Idle is shaky in the 1200 to 500 rpm range till warmed up and stays at a 740 rpm then the car runs okay. The smell of gas is strong, as well as the new spark plug tips are all yellow now, meaning a misfiring problem. Also there is a loud sewing machine like tick sound that gets faster and louder when speeding up. I did a valve adjustment three times to .010 in and it never decreased the sound.

:pimp:
hey brennan

[BANSHI]

I had the machine shop repair the head, so I don't think there's any missed bent valves, I hope.I adjusted the valves while it was cold each time.

So I guess I'll rip everything apart again and see if I can get the timing marks perfect then post the results.

Hey Cody haha

[fresh_TD]

Did you upgrade your injectors by any chance?

Sent from my GS4 Active

[BANSHI]

http://www.youtube.com/watch?v=qW4PJEPJRqU

Here is the sound i'm talking about give it a listen

[603Racing]

That's definitely a noise. Did all your valves adjust to spec properly? Sounds like it's just one valve/rocker/whatever it is. It does not sound healthy though.

[BANSHI]

I just rechecked the timing belt, corrected the half tooth off problem, didn't fix the sound issue, but it does run a lot smoother. I'm going to cut the head off tonight and see what's wrong.

[jalopi]

but it does run a lot smoother. I'm going to cut the head off tonight and see what's wrong.

Good to hear it's running right. Funny how being off such a small amount can make such a big difference, huh?

Also, wtf is 'cutting the head off'?

[BANSHI]

haha cutting the head off means, removing the cylinder head.

I just took it off 2 days ago and am still waiting on the results from the machine shop to hear if there was a valve bent or if the valve wasn't seated right.

[BANSHI]

Would a vacuum test cancel out a bent valve if all the ports passed? I just got the head back and the machine shop said the vacuum test found nothing?

[jalopi]

Was the car running/idling fine after you fixed the timing? I know you said it ran better, but didn't go into details.

If it was running, especially driving down the road fine and had power, you most likely didn't have any bent valves.

[BANSHI]

I drove it around the town for a little bit. Idling when warm was fine. Didn't seem to lose power when accelerating at all. I've read that it could be a faulty injector? I'm going to buy a stethoscope to isolate the sound tonight.

[jalopi]

Older injectors can be noisy - as can misadjusted valves, but those really aren't too bad to do, especially compared to pulling the head, lol.

**Just noticed you posted a video up... sounds like valve adjustment to me. At least 1 rocker is 'loose', like 'popped out six kids' loose.