Timing Chain noise?

[rjcaptsean]

Hiya folks,

I posted this video on Bfc. but didn't get much feedback (any actually) so I thought I would post it here where the M42 guys hang.   The video is visually sucky as I was moving my camera phone around trying to pin point the noise, but you can clearly hear the rattling in the Timing Chain area.   I hope to pull the front end apart when I get home, but until then I was hoping to pick your brains regarding just what I can expect to see.  Here's the video:

http://s361.photobucket.com/albums/oo57/rjcaptsbmws/?action=view¤t=ChainRattle.mp4

It is definitely mechanical in nature, not exhaust noise.  When I had the valve cover off I inspected the gears and chain and both seem to be in fairly good condition.  Gears were rounded but full and the chain was tight with no loose links.  The rubbing you hear in the background is a trashed Clutch Release Bearing.  That will go away when I replace the trans in a month or so.

Could one of the tensioners or the idler pulley gone belly up?

[DesktopDave]

That does sound like a chain-related issue.  Mine is loud (every M42 is) but nothing like that.  I'd be very tempted to pull the lower cover and find out what's going on.

Have you done any other work to the timing chain?  Updated the chain tensioner?

If you don't want to pull the front cover, at least drop the lower pan and see if anything has showed up in the sump.  The idler bearing and chain guides are both weak spots, replacing one early can save a timing case.

[rjcaptsean]

I was going to drop the lower pan to check for loose bolts, but I saw that it was semi-recently replaced as there was a fair amount of silicone sealant on the gasket material.  I know that doesn't mean much, but I figured at least it wasn't the original gasket.   But I tend to agree in your thought about the Idler and tensioner.   $100 for the tensioner alone though...ouch.

[DesktopDave]

Yeah, it's an expensive job either way, both in time and money.  It's far cheaper than a head rebuild, however.

I just pulled my pan to check last month.  Happily it was as clean as could be.  I did note that there was a bolt impact on the pan & pickup.  I torqued all the bolts down a few more pound-feet.

[2761377]

...But I tend to agree in your thought about the Idler and tensioner.   $100 for the tensioner alone though...ouch.

you don't have to pay that much. pelican sells german aftermarket tensioners for $40. if you join bmwcca you can get real discounts on parts from the dealer. i just last week got a discount from $107 'list' to $55 'your price' with club discount. that's enough to pay for a years' membership.

hth

robert w.

[rjcaptsean]

Hi Guys,

I updated my thread over at Bfc and I didn't want to double post all of the pictures here and there.  If you get a chance, could you please check out the update
http://forums.bimmerforums.com/forum/showthread.php?t=1518477
and perhaps feed me some responses?  
Thank you!

[DesktopDave]

You're really into that car...nice to see that kind of commitment.  I was tempted by a black one a little while ago.

The coolant/oil mix has me worried.  I'd absolutely do the head gasket & have the head & valves checked.  It's not something I'd want to do twice, and the parts are reasonable.

Not that your car is running now, but how did the exhaust mods work out?

[rjcaptsean]

Thanks a ton for the response.  My wife thinks I should be committed all the time.  Fortunately the State Hospital won't take our health insurance.  


Definitely going to pull the head now as the extra gaskets are only about $60 at this point.  (Already has all new upper/lower intake and valve cover gaskets.)  Hopefully it will just be a clean up job and no machine work will be required.  I will call around and see what a valve job would run, but if there are no major flaws, I might just let it go.  (LOL.. like that has worked so well for me in the past.)  

As for the exhaust, I wanted to take care of the rattling noise before I drove it any further, so the new cat and resonator are sitting in the trunk at the moment.   Since the PO did such a chop job on it, I feel it is probably better to let the muffler guy have the entire car up on a rack to refit it rather than taking just the pipes to him.

[rjcaptsean]

Lots of updates on this one over at Bfc.

http://forums.bimmerforums.com/forum/showthread.php?t=1518477

[318lotis]

my previous sterling silver started making the exact same noise after a butcher mechanic used a sledge hammer to remove the water pump.

 needless to say, the timing chain collapsed a few days later while driving 80 miles per hour passing a semi in a rain storm.

[rjcaptsean]

After I wrestled with the water pump for about an hour, I finally got it off without damaging it.  In the process of cleaning the gasket material up, I found a small, hardened insert on the timing chain case.   Upon closer inspection, there is a matching, empty threaded hole in the waterpump at about the 11:30 position. Right between the large 8mm bolt and the smaller 7mm bolt on top.  I can only assume that you use that hole to thread in a 7mm bolt to help "push" out the waterpump.  Just like the ones on break rotors and drums.  Those sneaky German engineers!

Check out the small hole just to the left of #4:

[DesktopDave]

That car really is coming together, you're doing a great job.  If I ever get the chocolate 325i back on the road I'll likely do something like this myself to my 318i.  Thanks for posting all the pictures too, good reference material here.

[rjcaptsean]

Updated the update...

http://forums.bimmerforums.com/forum/showthread.php?t=1518477

[DesktopDave]

I really hope to get that done to mine one day...

Strangely, many of your pictures are double-posted?  Odd.

[rjcaptsean]

Fixed it...  Not sure what the heck is happening other than trying to post from Germany.  Maybe server issues?