Author Topic: Tensioner question (Read 4817 times)

lqbanotxano · « **on:** March 09, 2012, 09:14:14 AM »

Have 187,000 miles on my engine. The PO (my next door neighbor) changed oil religiously & used strictly synthetic The car had the valve cover off a few thousand miles back & the cam gears looked fairly square.. not sharp at all. I have a little chain rattle at idle. Would it be a good idea to put on a new chain tensioner? Or�is this one of those things best left alone? I plan to put another 50,000miles on this car.

lqbanotxano · « **Reply #1 on:** March 10, 2012, 03:43:24 PM »

This is a serious question.
Any knowledgeable opinions?

DesktopDave · « **Reply #2 on:** March 10, 2012, 03:55:13 PM »

I've removed and re-installed a few hydraulic tensioners on my 318i and other motors and that's never caused a problem. Were I re-doing the cam gears, I'd do the whole deal - updated tensioner, M44 timing case, new guides, etc.

But for a good looking motor, I'd personally skip it. I've seen a few occasions that a new cam tensioner was installed right before a timing chain/guide or idler gear failure. Perhaps the new tensioner stretched the chain and accelerated wear? Or it's totally coincidental and I'm talking out of my hat? I don't have hard data either way, just a hunch. Sorry...less "knowledge," more "opinion."

d.hitchcock · « **Reply #3 on:** March 10, 2012, 03:56:15 PM »

Having just torn into my M42's timing components recently for the first time, I'm basically a noob.

My car was rattling on cold start for a minute or two, especially when ambient temps were under 50 F.

What I found on my 150k mile engine was moderate wear on the drive and cam sprockets and a broken lower guide. I replaced all that stuff -- chain, sprockets, guides, tensioner, etc.

Your tensioner, if original, is probably soft too, and you likely have wear on the accompanying chain guide.

Desktop Dave has a far more informed viewpoint on this stuff, and he's leery of changing just the tensioner.

You need his take on this.

EDIT: And I see now he was posting as I was writing this. Cheers!

d.hitchcock

DesktopDave · « **Reply #4 on:** March 10, 2012, 04:05:31 PM »

Informed or just plain lucky? Who can tell?

d.hitchcock · « **Reply #5 on:** March 10, 2012, 05:25:06 PM »

Wait, I was betting on informed! Should I hedge???

:D:D

rob_e30 · « **Reply #6 on:** March 10, 2012, 08:17:18 PM »

It's cheap insurance. Change it.

lqbanotxano · « **Reply #7 on:** March 12, 2012, 09:32:31 PM »

Should I worry about going to red line with a little chain rattle at idle...that is the question? I am new to the M42. How dependable is the engine, although well cared for, with high mileage? The gears are not sharp...I looked at them. The engine has 187,000 miles.

bmwman91 · « **Reply #8 on:** March 13, 2012, 01:50:43 PM »

Change the tensioner. Worst case, you throw away $40. I would not drive an M42 hard if it is making timing chain noises. This was something I found out the hard way when my oil pump sucked up a chunk of chain roller & blew up my timing case.

n2motorsports · « **Reply #9 on:** March 13, 2012, 03:35:42 PM »

Another vote in favor of swapping it. I swapped mine out when the car had 180k too; ran fine afterwards for 4 years then suffered a blown HG from an unrelated part failure.

lqbanotxano · « **Reply #10 on:** March 13, 2012, 04:15:39 PM »

If I do change it....is there an upgraded tensioned?
It seems to me that I read about an updated/upgraded tensioned...or am I imagining things?

DesktopDave · « **Reply #11 on:** March 13, 2012, 06:33:17 PM »

The M44 part supersedes the older M42 part. So yes, it's definitely been upgraded.

Here's a good description:
http://e30world.com/engine/BMW-E30-M42-timing-chain-tensioner-replacement

Pretty sure the upgraded PN is 11311743187

lqbanotxano · « **Reply #12 on:** March 13, 2012, 08:06:54 PM »

Thanks DesktopDave...

d.hitchcock · « **Reply #13 on:** March 13, 2012, 08:33:12 PM »

And just in case you want to go through the whole magilla ...

Here's a mess of M42 timing bits, with 1k miles of use, for sale cheap.

http://www.r3vlimited.com/board/showthread.php?t=241620

Gabs · « **Reply #14 on:** March 14, 2012, 10:27:07 AM »

Even though I think this topic has been concluded. I'd imagine if you have Square cam gears at 187,000 miles, its likely someone has been in that timing case atleast once. Hard to say if everything would have been replaced, though you'll probably be ok just starting with a new tensioner. My cam gears looked like sharks teeth at 200,000 miles, I assume they had never been changed.