Author Topic: Whining Chain Drive on new setup (Read 14016 times)

peerless · « **on:** June 02, 2008, 10:53:43 AM »

Hello all,

Just finished totally rebuilding a M42 engine and have a question regarding a rather loud whining noise from the chain assembly. If the chain wasn't so loud I would consider this normal. While I still don't consider this to be totally a bad thing, it is rather concerning considering the amount of work and money put into this engine.

My personal thought on this noise is that it is caused by the new style tensioner which is a M44 tensioner. The reasoning for this line of thought is due to the fact that the M44 tensioner is about 1/8" longer then the original tensioner. This would place more pressure on the chain assembly. I have done timing belts that are setup tight initially and they have had a 'Supercharger' type whine that goes away in about a month or two of operation. So I am assuming this chain whining noise to be a similar circumstance.

This is my first M42 engine rebuild so I have no reference to go by.

Is there any shops that you guys know of I can forward my information to to get further information? How many of you have had a similar problem and what was your resolution/outcome?

I did talk to Teddy Rowe at Metric Mechanic and he has heard similar noise but never as loud as ours is. He only showed mild concern.

Every timing component has been replaced at a cost of about $610. This includes every guide rail, sprockets, idler gear, chain, tensioner, etc.

The engine itself has excellent oil pressure as we installed a gauge in the car to make damn sure. It runs excellent, wrapped it up to 7k rpm and ripped the tires loose on the 2nd gear shift. So I really don't think there is any major problems, just a very loud chain. Also we have had it running with no belts so its not any of the accessories. (Alt, A/C, PS)

Here is a picture of the chain setup during assembly:

And here is a video where you can clearly hear the chain whining. Any feedback is appreciated.

1rst one with open headers, you can still hear the chain whine over the exhaust.

And here is one after the exhaust has been fixed and the chain is really loud.

peerless · « **Reply #1 on:** June 03, 2008, 01:43:06 AM »

So no one has replaced their timing chain or rebuilt their engine?

No comments?

Interesting. :confused:

swiss318is · « **Reply #2 on:** June 03, 2008, 02:30:53 AM »

..its definitely too much pressure on the chainguide comming from the chain tensioner!i had the same problem..

it started with a rattling ot the chain, then i took another chain-tensioner out of one of my 4 engines and put it in. after that the noise was exactly like your engine sounds! this tensioner was about 2mm longer..!
the problem i have .. i have 4 different chain-tensioner comming out of 4 "identically" engines?!
no i solved the problem with swapping around the chain-tensioner... on my new engine i am gonna replace all the sprockets, rails and the chain. we will see which chain-tensioner fits..

nicknikolovski · « **Reply #3 on:** June 03, 2008, 04:47:39 AM »

Hi guys, I have got the same timing chain whine coming from my engine. I replaced everything in the timing system as peerless did except for the timing chain tensioner piston.

I changed my tensioner piston one month previously thinking this would solve my rattling chain issue. I then changed all the guides, sprockets and chain. I reused my M44 tensioner. One thing that did concern me was the fact that I couldn't get the tensioner piston to compress in the vice. It would not click so I just installed the tensioner piston uncompressed.

So swiss318is, your saying that turning the piston around and installing it will cure the whine. That's interesting. Are you 100% sure?

swiss318is · « **Reply #4 on:** June 03, 2008, 06:13:08 AM »

Quote from: swiss318is;50521

..now i solved the problem with swapping around the chain-tensioner...

i mean i took 4 chain-tensioners from 4 engines and tried one by one!!sorry

peerless · « **Reply #5 on:** June 03, 2008, 01:29:01 PM »

Kinda makes me wish I hadn't thrown the original one away.

Nick writes:

Quote

One thing that did concern me was the fact that I couldn't get the tensioner piston to compress in the vice. It would not click so I just installed the tensioner piston uncompressed.

Maybe its in the installation that causing the problem. I read that you are supposed to install the tensioner 'uncompressed' and then release it by prying back on the chain guide and letting it release.

If we are releasing it before installing, maybe it is extending and then not compressing once installed. Looks like I may have to pull the valve cover, install the piston uncompressed, and then release it once its installed. But this procedure is only for the M42 style tensioner that is no longer available to my knowledge.

When I review the manual it say the early style tensioner should be compressed until it 'clicks' in the compressed position. After installation, push against the chain guide to release. It also states that the later M44 can be retrofitted, and from my understanding this is the only one available any more. After we 'uncompressed' the M44 tensioner, I was unable to even get it to budge, so I installed it 'uncompressed'. I just recieved another one today, but I might try to 're-compress' the one installed now and try to reinstall it and see what happens.

I will post my results here later today to let you know.

colin86325 · « **Reply #6 on:** June 03, 2008, 03:35:58 PM »

I believe the problem is that the tensioner has extended the full length of its travel.
Therefore, the tensioner must be reset to the beginning of its travel.

Page 11-42/4 of the factory repair manual explains this procedure. You can navigate to the document here:
http://ee1394.com/bmw/docs/factory/repair/en/index1.htm

The tensioner is designed to grow in length over time. Sometimes it can accidentally come undone so that it extends to its full length, which can cause the tensioner rail and chain to be damaged. You need to reset the length every time you remove the tensioner cap, and during initial installation if it has come undone.
The M42 tensioner automatically adjusts after being run at 3500rpm for about 20 seconds.

peerless · « **Reply #7 on:** June 03, 2008, 05:16:59 PM »

Hello again,

Well I removed the tensioner and it was extended to its full length. I compressed it in the vise 4x to get all the oil out, which wasn't much. The part I don't understand is that it simply comes back out under spring pressure. I compressed it again by hand and it simply comes back out again.

I got it to stick in about half way after fiddling with it for a bit and stuck it back in the engine. I fired it up and got a brief chain rattle that went way in about 1 sec. I let it idle for a bit and then brought the rpms up to 3000 and held it there for about 20 seconds as Colin recommended.

It did seem a bit quieter, thank you. But...I went for a little drive up and down the street and the noise came back? I have no idea at this point.

Also Colin the tensioner details are on 11-14/42.6 and only in regards to the original M42 tensioner which has been superseded to the M44 tensioner and is no longer relevant.

To be honest I am a bit annoyed at this problem and find it hard to believe that something like a chain tensioner can be such a pain in the ass.

nicknikolovski · « **Reply #8 on:** June 04, 2008, 07:03:57 AM »

Thats interesting info peerless, cause when I recieved the tensioner from new it was already in the compressed position and then when I had to change the chain a month later, it just would not compress at all.

Also how is possible to push the tensioner rail back against the piston if the timing covers are in the way?

colin86325 · « **Reply #9 on:** June 04, 2008, 07:55:55 AM »

Quote from: nicknikolovski;50604

Also how is possible to push the tensioner rail back against the piston if the timing covers are in the way?

This is for the M42 tensioner.
I believe you have to remove the upper timing cover. Or get lucky with a long skinny screwdriver.

peerless · « **Reply #10 on:** June 04, 2008, 12:28:25 PM »

Just remove the valve cover and a long skinny screwdriver will work. But again thats on a M42 style tensioner which is NLA.

As a side note:
On the M10's and M30s you actually have to work it back and forth until it pumps up.

nicknikolovski · « **Reply #11 on:** June 05, 2008, 04:40:37 AM »

Has anyone else experienced this whining noise from the chain?

Also why doesn't the M44 tensioner want to compress?

colin86325 · « **Reply #12 on:** June 05, 2008, 08:23:52 AM »

We replaced the tensioner w/ another M44 tensioner and all is well. Install the new tensioner in its compressed state. It will rattle for a second or two and then the noise goes away.

91_318i · « **Reply #13 on:** June 05, 2008, 02:37:47 PM »

Quote from: colin86325;50660

We replaced the tensioner w/ another M44 tensioner and all is well. Install the new tensioner in its compressed state. It will rattle for a second or two and then the noise goes away.

so you installed a new m44 tensioner fully compressed and now the noise is gone?

and all you did was start up the motor to get it to extend?

colin86325 · « **Reply #14 on:** June 05, 2008, 06:04:16 PM »

Quote from: 91_318i;50680

so you installed a new m44 tensioner fully compressed and now the noise is gone?

and all you did was start up the motor to get it to extend?

Correct.