M45 VK45de timing chain rattle

[philb]

I have 80K on my M45. Timing chain tensioner appears not to be working properly as there is a rattle behind the cover on the passenger side of the engine (I located this with my stethoscope).

I have always been good about changing oil and filter, so I'm a little frustrated with this issue.

I am trying to decide whether to just replace the tensioner as the FSM suggests could be the problem, or replace the whole timing chain, as 80K has surely weakened it. I am planning to replace timing chain, drive gear (cam gears are too expensive) and both tensioners.

Anyone had this issue, or have any suggestions?

Surely someone has come across this on the VK engine by now. I'd like to learn from someone else's experience if possible.

I'll probably tear the front down this weekend to see what's going on in there!
Modified by philb at 9:35 AM 4/16/2009

[philb]

Well:

I guess I can assume from all the response from everyone (not) that no one else has yet encountered this issue.

Well, the good news is, it looks like I haven't either...I thought I would pull the belts off and run the engine to see if the noise went away, and it did.

It was a bad bearing on the belt tensioner on the alt/waterpump/ac belt.

Now if I can find a bearing to press into the pulley I'll be back on the road.

[szh]

I am glad to see that you were able to diagnose this problem, and it is an easier fix than originally anticipated. Whew.

Z

[philb]

Thanks for your concern. I wasn't really looking forward to it, just knew the noise wasn't right.

I sure enjoy reading about everyone's experiences with their M.

I hope I can keep this thing running for 200K at least.

philb