Sunday, February 12, 2012

Time for A Timing Chain?

Recently when the engine has been running for lengths of time a "rattle" has emanated from the front of the an erratic timing mark last time I set the timing....all signs of a worn timing chain. I pulled the front cover off the engine today....this required removing the exhaust...which required removing the sidecar sub frame....which requires removing the sidecar....sort of a domino effect.

The whole scenario took about 3 hours to get everything disassembled and the timing chain exposed. I've never gone into the front of a BMW engine before but it was pretty straight forward. The stator mounting bolts were stuck so I heated the aluminum at the block with a heat gun before I stripped the allen head out. Heating did the trick and the stubborn bolts finally broke loose.

Upon removal of the cover it is obvious that the chain needs replacement. The spring loaded idler arm was pretty much out of travel.
I'll also replace the camshaft seal and crankshaft seal when she goes back together.

The old idler arm (Top) shows wear from slapping into the engine housing....I imagine this was the source of the noise I was hearing.

I had ordered a timing chain from a San Diego BMW shop but they did not order what I needed....which was a master link type chain....rather they sent me an "endless" chain with no master link. Utilizing the "endless" requires removal of the outer bearing and both drive sprockets.
In reality the gears should be changed but at over $300.00+ for those parts, I'm just going with a timing chain at this time.
I'm hoping to get my supplier in Florida to Fed EX overnight another chain and master link I need so I can get her back together this week...we'll see....

We're hoping to make it to the Airhead Beemer Club Death Valley Rendezvous by the end of the week.....

Hans, owner of Hucky's BMW in Florida, made an exception for me this morning and will Fed Ex Over night my parts to me today. He typically does not do Fed Ex Overnight as he must hand deliver the package. By chance he is off on Mondays and runs, one of his errands will be my parts delivery to a Fed Ex Office...Service which I could not have gotten from anyone else!

1 comment:

Houston said...

Doug! Looking at timing chain issues and stumbled upon your site.

Dan's /5 started making a terrible racket at higher RMP's and to my ear it's coming where a timing knock would occur.


I'm in San Mateo, CA at Dan's. Made it in town and the frontend got so sketchy something had to be done and lucking I stumbled into Greg Hutchinson's territory.

Hope the travels are well and where the hell are yall? Be sure to give Darien our best.

Gila Mtns.

Gila Mtns.