E36 325 Upper Cam Tensioner Replacement

[pwhittle]

My son has a '93 325is and there is a rattling from the upper cam area. My suspicion is that it is the upper cam chain tensioner that could use replacing.

I have a few questions:

1 Does my diagnosis sound correct?
2 Is it necessary to remove the cam sprockets to replace the upper cam tensioner, meaning, will I need the cam locking tool?
3 I know I will need a valve cover gasket. Is there anything else I should order to get ready for the project?
4 Wayne, you mentioned that you were working on writing up this project a while ago. Were you ever able to finish the write-up?

Thanks in advance

Paul

[Jeron]

Are you replacing the tensioner piston or the tensioner guide rail?

[pwhittle]

I did not realize till you asked that that the guide rail was a part that could or should be replaced.

Is it normal to replace both at the same time?

Paul

[Jeron]

The part that is most commonly replaced is the lower chain tensioner piston assembly, which can be replaced externally and easily. I've also heard of replacing the lower chain tensioner guide but that is clearly more involved.

I haven't heard of replacing the upper chain tensioner. It looks like the upper chain tensioner has the guide rail integrated. The guide rail on the other side of the upper chain probably would not wear just as the guide on the opposite side of the lower chain is not usually replaced.

The part of the upper chain I hear replaced most is the VANOS unit.

[sumyungguy]

subscribed for more info

[pwhittle]

Are there any diagnosis recommendations that will indicate which part needs to be replaced?

Paul

[Jeron]

Chain rattle is common and most people just live with it. If yours is severe I would first replace the lower chain tensioner because it is a fast and simple procedure although a bit pricey at $100.

I don't know of any ways to diagnose which parts need replacing but a stethoscope might help isolate if it s the upper or lower chain.