PDA

View Full Version : Cam chain rattle question

twins4life
10-18-2005, 03:53 PM
1997 R-1100R, 33,000 miles.

At 3-4k RPM I get what sounds like a loose cam chain. Sounds like the chain is going slack and rattling against the case.

1. Is this unique or a known bug?

2. Are the ACCT tensioners spring loaded or do I need to adjust them. If spring loaded, can I buy an aftermarket manual type?

Thanks!!
lorazepam
10-18-2005, 04:13 PM
Try this list search for tensioners (http://www.bmwmoa.org/forum/search.php?searchid=90296)
twins4life
10-18-2005, 04:23 PM
Lots of good info there, thanks.

Looks like I need to determine if I have the upgraded ACCT thingy. Come to think of it, the rattle seems to be on the left side...
twins4life
10-19-2005, 02:58 PM
Help!

11 31 7 688 629 unavailable
11 31 7 656 922 unavailable
07 11 9 963 308 $0.69

These numbers are from the AVRider thread.

Any ideas?
lorazepam
10-19-2005, 04:50 PM
Live with the rattle? maybe get a loud exhaust?
twins4life
10-19-2005, 05:26 PM
The rattle I can live with. It's the specks of aluminum in the oil from chain contact I dont like. Sure the oil filter grabs them but only after the oil pump picks them up and they have been splashed around the inside.
JimmyC
10-20-2005, 08:46 AM
If you live with the rattle you run the chance off destroying the guide rails the chains run in. These are plastic, strong plastic but still plastic. Take off the valve covers and inspect these rails especialy the lower left one. If this one breaks the case has to be split to replace it. This is not a fun job. Don't ask how I know. Sometimes noises are trying to tell you something.

Jim Creighton
Williamston MI.
lorazepam
10-20-2005, 04:09 PM
why not just replace it with the one they sell now? Why anguish over rebuilding it, see if the R12 one will work.
Cancel that last thought, they havent been around long enough to see if they would be any better.
twins4life
10-20-2005, 04:56 PM
New idea, since the parts wernt available I tried a different approach.

I took the tensioner out, measured the spring free length and stretched it 1/4".

Seems to be quieter now.
rado360
10-21-2005, 08:47 PM
I bought new springs for .50 cents each and compared old ones before replacing them,old ones with about 50,000 miles we're about 1-2 coils shorter than new.New one will last longer than stretched ones I think.

Tim
twins4life
10-24-2005, 03:49 PM
Agreed, new springs are in order for both sides but stretching the original spring as a quick way to see the effect.