Timing Chain Rattle

[MaxBell]

Hey guys,

I have a noise in my M50 that appears when I get into higher RPMs and on decel.

Does anyone know if the actual rail has to be replaced? It seemed fine when I had the engine apart before it went in the car.

Can I replace just the tensioner or is that a waste of time?

(this thing, or do I have to do the rail as well?)


Also: will an S50 tensioner fit a M50?

[328ijunkie]

Depending on the sound it may be the vanos, the upper tensioner, lower or all of the above....

[110stx]

On an M42 I didn't have to deal with any vanos issues, but in replacing the timing components discovered a broken guide and significant wear that created timing chain rattle.

[MaxBell]

Should I just replace everything while I'm in there? Or is there a way to diagnose further?

[328ijunkie]

Depends on your budget. Lower is obv really easy to replace. If that dont fix it then you usually do the vanos seals and upper at the same time.

[MaxBell]

So for anyone else trying to fix a timing chain rattle that moves with RPM and your tensioners are all ok, it's your timing.

My primary chain was off by 3 links, which threw my secondary chain off as well.