M42club.com - Home of the BMW E30/E36 318i/iS

DISCUSSION => Engine + Driveline => Topic started by: ob_318is on September 07, 2008, 08:06:56 PM

Title: BROKEN SPROCKET STRUCTURE - The source of my problems
Post by: ob_318is on September 07, 2008, 08:06:56 PM

Okay so today I took my lower timing case apart, and removed parts to fix timing problems. Attached are some images of what went bad.

(http://firstplacelosers.com/bmw318_broken/DSC06100.JPG)
The engine...

(http://firstplacelosers.com/bmw318_broken/DSC06093.JPG)
Broken sprocket chain slanted forward

(http://firstplacelosers.com/bmw318_broken/DSC06094.JPG)
After a closer look found that the structure was broken ;x

(http://firstplacelosers.com/bmw318_broken/DSC06116.JPG)
Lower timing case, marks left by chain rubbing.

Title: BROKEN SPROCKET STRUCTURE - The source of my problems
Post by: Jimmy Lewis on September 07, 2008, 08:17:18 PM

Well I guess you know what is in order now. That has to be a super rare situation though, for that to just shear off like that. Good luck getting it back together and getting it running again.

Title: BROKEN SPROCKET STRUCTURE - The source of my problems
Post by: quinn11m20 on September 07, 2008, 09:19:22 PM

wow! hey did you hear a chain kinda noise? not a chrunching noise, a rolling noise . Like the chain is kinda slack. Now I have replaced my tensioner spring a few months ago and really still have the chain noise. Any thought? I would like the input.

Title: BROKEN SPROCKET STRUCTURE - The source of my problems
Post by: quinn11m20 on September 07, 2008, 09:21:16 PM

Oh and are those the original guides? I want to know if the noise I have is because they might be worn regardless of the tensioner piston. Thanks oh 318is.

Title: BROKEN SPROCKET STRUCTURE - The source of my problems
Post by: ob_318is on September 08, 2008, 08:09:16 PM

Quote from: quinn11m20;56241

wow! hey did you hear a chain kinda noise? not a chrunching noise, a rolling noise . Like the chain is kinda slack. Now I have replaced my tensioner spring a few months ago and really still have the chain noise. Any thought? I would like the input.

Not sure on the noise...because my situation was different from many others, but if you changed your tensioner and you still have that noise, then its your guides. If you do happen to go as far as checking guides, might as well do the chain and sprockets.

Title: BROKEN SPROCKET STRUCTURE - The source of my problems
Post by: quinn11m20 on September 08, 2008, 08:51:23 PM

ok thanks, that is is exactly what i wanted to know.

Title: BROKEN SPROCKET STRUCTURE - The source of my problems
Post by: mark_i on October 02, 2008, 11:28:46 PM

Hi Everyone. This is exactly the same situation that I have as well.
Last month I posted a thread about my exhaust cam sprocket jumping 7 teeth.
Many of you asked me how the hell could that have happened... at the time I didn't have a clue. Now you know...

I'll get the pictures up if only to show you how similar to ob_318is for this mode of failure was.

Title: BROKEN SPROCKET STRUCTURE - The source of my problems
Post by: strypt on October 03, 2008, 02:43:17 AM

I've seen it a couple of times aswell. Not that uncommon.
M42 E36 engine has that sprocket removed and a guide is there instead.

Title: BROKEN SPROCKET STRUCTURE - The source of my problems
Post by: nicknikolovski on October 03, 2008, 03:41:08 AM

M42 E36 has the guide put in post 09/93. Pre 09/93 has that deflection wheel.

Title: BROKEN SPROCKET STRUCTURE - The source of my problems
Post by: dude8383 on October 03, 2008, 09:53:38 AM

holy crap man!

i hope you get back on the road with the piece i gave ya =)

Title: BROKEN SPROCKET STRUCTURE - The source of my problems
Post by: hoevesruperd on October 03, 2008, 12:28:38 PM

i parted out an e36 with the exact same problem

Title: Got it back on the road!! - Still with issues
Post by: ob_318is on November 24, 2008, 09:39:12 PM

Hey dude8383, thank you very much for the lower timing chain case. I put it on been 2 months now. After I got the car back together, I started the car up, but it was not keeping idle. So I ran a compression test, seems like I lost 2 cylinders, guessing I have bent valves..which sucks now that the car is back in one piece.

I have been driving with about 2-3 working cylinders... I recently found a guy from Canada (logger) that sold me a cylinder head w/o cams. I was looking around for you but lost our number and did not remember your username on the board, was gonna ask you for the head. (If you still have a head let me know)

Once I receive the head from Canada, I am going to install it hopefully al goes well and wish me the best on this..truthfully ever since I picked up this e30 (M42) its been a nightmare, loving driving the car, but I am not getting the full effect....