Chain Tensioner Questions

[khnordeen]

As of late my car has developed some symptoms that make me think the chain tensioner is toast. My car has developed a loud rattle, which gets louder as it revs.

I have done some reading, and have read conflicting things regarding how long it takes to replace the tensioner. I have read on here that it can take 3-4 hours to replace, while other sources I have read have said 30 minutes.

Post #8 in this thread says "10 minutes": http://forums.bimmerforums.com/forum....php?t=1379176

30 minutes listed here:

http://www.esatclear.ie/%7Ebpurcell/318isfaults.html#timingchaintensioner

This post says "3-4 hours":

http://www.r3vlimited.com/board/showpost.php?p=2377822&postcount=24

So which is it? Also, what tools specifically are required to do the job?

I appreciate any help. Thanks

-Kyle

[Ryann]

How many miles on the engine? If you're 100k-150k I'd say try replacing your tensioner piston first. It's around $40, part #11311743187 and usually resolves this issue. To change the tensioner you'll need a 19mm wrench, a rag, and 3 minutes of spare time.

If you're up around 200k I'd say you're looking at more tools, more time, and more money.

[Ryann]

BTW,
More time=6 hrs.
More tools includes a 1/2" drive impact gun or Super Cheater to remove crank pulley nut.
More $= something like $500 worst case scenerio (gears/chain/guides/tensioner/piston/idler gear) IIRC.

[rjcaptsean]

The loud rattle could definitely be the tensioner. There is a spring inside of it that wears after a long period of time and doesn't let the tensioner push on the idler guide firmly, which in turn leads to slack in the chain.

IF all you are doing is swapping out the tensioner, all you will need is a 19mm socket or wrench to remove the tensioner cap. (It looks a lot like a large oil drain plug.) Once that is off, you should be able to pull the tensioner out, replace it with the new one, and screw the cap back on (with a new crush washer to keep it from leaking oil, of course.) Literally, that is all there is to it. Probably between 10-20 mins.

I had that same noise, but I wasn't really familiar with how the timing chain guides and tensioner worked, so I pulled the valve cover off to see the chain and top guide. Since I didn't see anything obvious, I then pulled the front cover off... after removing the thermostat housing and water pump, and that led to replacing all of the guides, but heck, I didn't see any obvious damage to the guides (as they get old, the plastic gets brittle and you expect to find pieces in the pan). So that led to pulling the head and then the engine and ..... You see where this is going? You just don't know what you have until you get in there.

I probably could have just swapped in a new tensioner, and the noise would have gone away, but this is going to be a daily driver for my bride, and I wanted to be 100% sure of what I had.

Your results may vary. :)

[vpilarrt]

The first 2 reference (10 minutes and 30 minutes) are just to replace the tensioner piston (like rjcaptsean described in the 1st half of his post) and really is 10-30 minutes depending how fast you work and how adverse you are to getting dirty. The 3-4 hour reference is if you have to change the chain guides that are located behind the front cover (like rjcaptsean described in the 2nd half of his post).