r1100rt - Airbox throttle valve noice

[crnagel]

When in idle I get this "click, click...." type noice coming ONLY from the right throttle adjusting B=fly valve/flapper. I touch it with my finger and it stops, it feels like it is opening and closing as it sucks air and not.

 

Any suggestions?

[T__]

crnagel, make sure the throttle cable isn’t too tight (needs slack) on that side & if there is a little cable slack just live with the clacking noise as most BMW TBI’s with a little wear on them make that noise at hot curb idle..

 

If you want to get creative you can re-bush that TBI throttle shaft bore but the noise will just come back..

 

Another alternative is to make a centering ball & new machined throttle bore cover that keeps the shaft centered & tensioned (I made one for my first oihead but all the effort just wasn’t worth it)..

 

Added: I probably should add that the L/F side seldom rattles as it has the TPS sensor on the outboard end of the shaft to keep the that end of the shaft pre-loaded enough to prevent rattling..

 

Twisty

 

[breyfogle]

Its a relatively common problem that seems to only effect the RHS throttle body. When it gets bad enough that the two TB's can not be balanced, the RH TB will need a rebuild. Lots of people have done it and there should be a fair amount of how-to information.

[crnagel]

Thanks a lot for the feedback. I'll start by letting the cable loose a little bit, I've noticed it was pretty tight.

 

I will also search for RH TB rebuilt as soon I post this answer. This is the time to get repairs done since it is a bit cold yet, although today it was 45F, tomorrow 52F...good enough for me!!

 

Thanks again..

 

CRN

[T__]

CRN, remember if you mess with the cables you then need to re-balance the TBI’s side to side.. Should check at hot curb idle,, then check & adjust the off-idle @ 2k,, 3k,, maybe 4k..

 

 

Twisty

 

[crnagel]

Thanks to y'all for the tech support and recomendations. Job finished and well done, TBI's balanced at idle and at 3,500 rpm thanks to my son, he will become an excellent BMW mechanic.