engine and drivetrain My Engine noise....Still not gone

[arminyack]

The car runs like a champ & pulls strong....I only really hear the noise at idle ( engine roar drowns it out)

 

New Mahle pistons, all machine work done by a reputable shop. I've got about 100 miles on it since the rebuild....I've checked the head bolt torque and checked the valve lash. Everything there is in spec.

The only funny thing I noticed when I assembled the motor was my timing chain was tight. (http://www.bmw2002faq.com/forums/topic/179823-timing-chainto-tight/#comment-1105488)

 

 

Here is how is sounds now:

https://www.youtube.com/watch?v=w2cKFvYwLDg

[Mark92131]

What value did you set for the valve lash?  .006 - .008 on a stone cold engine is specified.  If you used .008, try .007 and see if the noise dissipates.  A noisy valve is a happy valve!  Check to make sure the oil bar is delivering adequate oil to all the cam lobes and the brass washers on the hollow oil bar nut were re-installed.

 

Mark92131

[arminyack]

I tighten down on a .008. This winds up with the .008 non being able to go in, but a .006 sliding in with a little resistance. Right now, I am suspecting the timing chain tensioner. I was never able to adequately bleed it, due to very little slop in the timing chain. Instead of the tensioner pushing itself against the chain, its the other way around in my engine. I'm going to put a stethoscope to it when I get home.

 

The noisy is most noticeable at idle, but doesn't go away when the engine is revved...the noise just gets drowned out. The noise is present when cold and when fully warmed up.

[arminyack]

and the stethoscope agrees; its the tensioner. I pressed the end of it to just about the tensioner "snout" where it meets the timing chain cover, and boom, there is the noise as plain as day. The chain was pushing against the tensioner to the point the tensioner was very close to the stop (the little wall inside the cover that makes the oil reservoir), and now I believe it is slapping against it, making that noise. Now....what to do about it.........

[percy]

If it has not been mentioned, the tensioner itself has specs and a spring with a specific length/tension.  I have not disassembled any tensioners in a long while, but could it be that yours is not fully compressed or seated?

 

 

 

See: http://www.bmw2002faq.com/forums/topic/138330-timing-chain-noise-replace-tensioner-as-precaution/

 

Another alternative is to use a mechanical timing chain tensioner.

 

 

[arminyack]

I have a number of pistons from a couple of engines I've torn down, plus some random ones....all of them measure ~58mm (including the new one in the car) ...and all of them with the parts pressed together, with seemingly no easy way to separate. 

[kbmb02]

15 hours ago, arminyack said:

Right now, I am suspecting the timing chain tensioner. I was never able to adequately bleed it, due to very little slop in the timing chain. Instead of the tensioner pushing itself against the chain, its the other way around in my engine.

 

Just to eliminate a possible cause, count the links on the timing chain (it would be weird, but - well - things happen). -KB

 

[Tommy]

There's also chains that fit but are thicker making it tighter. That was from some Mercedes. Just thinking a chance that some manufacturer or retailer hasn't paid attention to thickness and sold wrong chain. Some builders use that to eliminate slack caused by skimmed head.

[arminyack]

On 5/24/2016 at 6:35 AM, kbmb02 said:

 

Just to eliminate a possible cause, count the links on the timing chain (it would be weird, but - well - things happen). -KB

 

47 links....then I counted them on my old chain...also 47 links. 

 

Whats weird is that I both resurfaced the head AND decked the block..I should have the opposite problem.

[dang]

Any other new components?  Timing gear?  How about the thickness of the head gasket?

[arminyack]

Timing gear is new....IE Adjustable. New tension rail, new OEM head gasket.

[Stevenola]

Is the tension piston new?  If not then rotating it 180 degrees may help due to previous wear pattern.  Also is it clean inside it and able to hear the ball bearing clink around when shaking?

[PatAllen]

if you talk about the noise it makes when reaching idle....my automatic 02 was making the exact same noise. i have a youtube video as well.

two things i changed, cured slap in the oil pump chain and had the pistons knurled to fit tighter. noise is gone.

what it was exacly ?

duno....

 

[arminyack]

Holy crap...thats the exact same noise mine makes! I can tell you that my oil pump change has less than 5mm of deflection. So now I am leaning towards piston slap....even though its the same sound whether hot or cold.

 

I put in a mech. timing chain tensioner today....noise still there.

Edited May 26, 2016 by arminyack

[arminyack]

I dropped the subframe, and oil pan today, and started to inspect the play on my oil pump chain. I noticed a good amount of side to side play. Is this right....it sure doesn't seem like it!!

 

Oil Pump Chain side play

 

I then measured the inside dim of the chain...

 

I found my old chain, and measured it:

 

 

 

Whats up with this new chain I put in? Was there any variance in the thickness of the oil pump sprockets?