Timing chain tensioner question

[AdironRider]

So Im replacing the tensioner tomorrow and Ive got a quick question. Ive had some conflicting reports on whether to install and run it at 3 grand for 20 seconds, or to have the tensioner spring out in some other way. Ive heard the 20 second method can be detrimental to the timing chain itself. Thoughts? Advice?

[DaN]

Why would you do either? just install it

[1991 318is]

Tensioner install.

Install the tensioner compressed - it should come that way - and replace the plug that holds it in. Use a screwdriver to push the rail and chain against the tensioner and then release it. It should pop out and put the chain under tension. You'll still need to start the motor and run it up to let oil pressure fill the tensioner. It will rattle for a few seconds until it's filled. Oil pressure keeps the tensioner against the chain and guides. I'm assuming you have an M42 four cylinder.

[AdironRider]

How do I get a screwdriver in there to release the tensioner?

[DaN]

Remove the valve cover?

[AdironRider]

Cool. I havent had to touch a thing on my m42 since Ive owned it, other than a couple oil changes so I dont know to much about how to work on it yet.

[mattdk318i]

i had no problem replacing mine. Took the cap off and slid the old one out. Reversed procedure for installation. Started the car up. Let it idle. Then goosed it up to 2K. Its been quiet and smooth ever since.

Matt

[AdironRider]

Cool, I need to stop being lazy and get this done tomorrow.

[1991 318is]

Releasing the tensioner.

How do I get a screwdriver in there to release the tensioner?

Take off the valve cover and the upper front cover. The one over the cam gears. See the repair manuals - Bentley or Haynes. You can also do like posted above and let the oil pressure do it. There are no covers to remove that way. Be prepared for some noise when you start it.