Cylinder head noise

[Keith M]

88 m20b25 in my 87, 99,000 miles or so.

Before I installed the new motor, I replaced all the seals, gaskets, yada,yada. Lots of noise from the head so I pulled it and sent it to a machine shop. New valve seats, guides and seals, reground valves, pressure check, re-install.
The noise is gone at idle, but comes back around 1500 rpm. If you slowly rev it up, you can hear it start - hhhuuummmmmtinkhhhuummmmtink till it becomes a steady tickticktick, maybe from one or two valves. It also seems to be affected by engine load. Under acceleration, it if fairly quiet, lift off the gas and it gets a lot louder.
I've done numerous valve adjustments at .010 and even tried .008 with no change.
Any suggestions?

Keith

[Court M3]

noisy injectors maybe?

[Keith M]

It's way beyond noisy injectors and builds with rpm's.

Keith

[BM5W]

Have you isolated the noise with a stethoscope? I had a weird noise the other day... turned out it was the fan hitting the black plastic distributor cover.

[Keith M]

It's hard to tell, Mark. Somewhere under the valve cover is as close as I can get. I wish I could make it run with the cover off.
I'm going to PIR tomorrow for the races and maybe Greg Miller or one of the other racers can give me some input.

Keith

[joshh]

I hate engine noises.

Is it possible it's the flywheel or clutch? I hate to say it but it sounds more like a bearing.

[BM5W]

Any chance the the crank scraper you put on is hitting the crank? I've heard of people having to grind a bit to get them to fit.

[Keith M]

I did have to modify the crank scraper to make it fit. It sounds like a broken rocker or a valve way out of adjustment.

Mark - can I borrow your car on Monday? heheheehe

Keith

[joshh]

I did have to modify the crank scraper to make it fit. It sounds like a broken rocker or a valve way out of adjustment.

Mark - can I borrow your car on Monday? heheheehe

Keith

But you just had the head done??

[BM5W]

I did have to modify the crank scraper to make it fit. It sounds like a broken rocker or a valve way out of adjustment.

Mark - can I borrow your car on Monday? heheheehe

Keith

Sorry Keith, I'm in Seattle! I would like to see it on the track though. You could show me where to pick up the 5 seconds that are separating me and all the other e30s out there.

Run Jennifer's car. I rode in it at the Porsche day... that thing is set up really nice.

[Keith M]

Sorry Keith, I'm in Seattle! I would like to see it on the track though. You could show me where to pick up the 5 seconds that are separating me and all the other e30s out there.

Run Jennifer's car. I rode in it at the Porsche day... that thing is set up really nice.

Thanks Mark. It's probably one of the fastest stock motored 328's out there (Jen might have something to do with that!) If there is room, I will run it in the advanced or intermediate group.
I think you would have 5 or 10 seconds on me seeing as I have never driven my car on the track yet. You do know the trick for turn 7 don't you??
No. MAYBE I'll tell you at some time.

Josh - It was JUST rebuilt. After talking to Ken Hill (PRO3 guy) this weekend, I have a few other things to check. It may be piston slap.

Keith

[BM5W]

Thanks Mark. It's probably one of the fastest stock motored 328's out there (Jen might have something to do with that!) If there is room, I will run it in the advanced or intermediate group.
I think you would have 5 or 10 seconds on me seeing as I have never driven my car on the track yet. You do know the trick for turn 7 don't you??
No. MAYBE I'll tell you at some time.

Josh - It was JUST rebuilt. After talking to Ken Hill (PRO3 guy) this weekend, I have a few other things to check. It may be piston slap.

Keith

How'd it go today? Did u end up running? Any incidents? I heard the weather was good. Trick for seven: really late apex? I'm actually having to pedal at the end of the back 'straight' to prevent from overreving my car in 4th.
I'm down to 1:37.6. Tim, with 2 less cylinders, is in the 1:33s... I have no idea where he makes that time!

Mark

[Keith M]

I took the car in yesterday to an independent BWW mechanic. He listened to it for a minute or two and said " Wow. I've never heard anything like that before" Great.
I'll know more tonight.

Keith

[Keith M]

Well, it stumped the mechanic. Compression is quite high at 200 +/-, leak down is in the single digits. Timing is fine also. Before I pull the head again, I'm going to swap the rockers and rocker shafts off the old motor and see if it makes any difference. I am beginning to hate this car.

Keith

[mpunklil]

did they mill your heads? if so, how many thousandths. Did you go w/ a softer material head gasket? if so, make sure you arent getting too much crush on your gasket. Your compression does seem a little high, and if your heads have been milled too much, and there is a lot of crush on your head gasket, it will raise your compression, and your piston could be hitting your valve/s. these are all things you need to account for. this is also a very unlikely situation i might add, BUT is possible under the right circumstances.