PDA

View Full Version : Broken timing chain



jga540iAT
12-27-2005, 02:12 PM
I've been driving @ 160km/h (3000rpm) back home after a few sunny days at the beach...suddenly, no power! I had electricity, decided to roadside troubleshoot. Luckily I opened up the oil cap first - no primary timing chain visible! There I was, stuck 200km from home...

Fetched the car today with a flatbed. Started stripping the motor - tappet covers, and yes, timing chain broke...

What can I expect to find? Must I lift the heads - maybe some valves bend?

I followed a thread posted a while ago from shogun, but url keeps timing(sic) out...

Thank you.

632 Regal
12-27-2005, 02:22 PM
this is the first time i heard of this!!! Take pictures!

Theres not really a way to check compression without the chain on there but if the valves are closed you could do a makeshift leakdown with an air compressor and a fitting welded to a broken sparkplug to see if its completely blowing past a valve. My guess would be some valves are bent, with 10 to 1 compression there isnt much room for clearance.

jga540iAT
12-27-2005, 02:28 PM
Pictures will follow as the stripping continues tomorrow.

Thanks for the input...

shogun
12-27-2005, 03:45 PM
I have heard of some V8 M60 engine with the same problem over the past 2 years. Bended valves because they touched. Needs removal of the head to see the damage. I remember one case where the engine had 184 k km.
Site is no more, but I found it with the wayback machine, here the pics
http://web.archive.org/web/20050215165810/people.freenet.de/Herbie01/Motor.html
Actual site name is
http://people.freenet.de/Herbie01/Bilder.html
One pic from the page
http://web.archive.org/web/20050215165810/http://people.freenet.de/Herbie01/bilder/kleinMotor11.JPG

It shows also the wear or not after 184 k km driving in Germany.

632 Regal
12-27-2005, 03:57 PM
great post Shogun! Looks like the oil was marginal at best. When I dragraced and dissasembled the thing between races that site was the sign of broken down oil, that could also lead to lack of lubrication for the chains too.

This guy might have more problems if this is the case...but I hope not.

grave77
12-28-2005, 01:20 AM
I saw an M20 with a cut off timing belt, all valves were fragmented into the pistons !! ... but cutting off the timing chain !!! never knew that would happend !! ....

emw525E34
12-28-2005, 03:32 AM
Yikes, I did not know that could happen!. I figured that chain lasts the life of the car. But now, may need to check the tensioner and possibly replace that . Anyone has the chain fail on an M50 engine ???.