Timing Chain 500 SEC

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

David Griffiths - 03 Feb 2005 21:08 GMT

I have heard that at a certain mileage it's a good idea to replace the
timing chain guides (which are plastic). However, I am not sure whether or
not the timing chain itself needs to be replaced.... Heard some say yes and
some so no. Any views out there? 1985 M117-963, 170.000 miles.

David in Seattle

Reply to this Message

Al Bolton - 03 Feb 2005 21:48 GMT

David,

I would replace the chain every 100,000 miles, and the chain tensioner as
well if possible. This was done on my 500SE (1990) at 126,000 miles. In my
case, the (duplex) chain did show some signs of wear, so I was glad it had
been replaced. It had started to rattle from start-up.

I've seen some scare stories about the guides going brown, becoming brittle
and then breaking, but I have never been able to confirm them. It's quite
likely that the guides broke AFTER the worn chain started hitting them. But
if you are going to change the chain, then do the tensioner (and the guides)
as well. At 170,000 miles, I think the sooner you do it the better!

Regards,
Al, Caversham UK
1990 500SE 137,000 miles
1988 260E 160,000 miles FOR SALE

>I have heard that at a certain mileage it's a good idea to replace the
> timing chain guides (which are plastic). However, I am not sure whether
[quoted text clipped - 4 lines]
>
> David in Seattle

Reply to this Message

Richard Sexton - 04 Feb 2005 23:01 GMT

>I have heard that at a certain mileage it's a good idea to replace the
>timing chain guides (which are plastic). However, I am not sure whether or
>not the timing chain itself needs to be replaced.... Heard some say yes and
>some so no. Any views out there? 1985 M117-963, 170.000 miles.

The timing chain should be renewed when stretch is unacceptible. You
can measure the degrees of chain stretch easily with the timing marks on
the cam towers.

At 170K miles the chain can still be well within spec if the coil changes
were kept up. If they wern't (and it doesnt' really take long) then you'll
probably need a new chain, and possibly tensionor as well. Guide you
replace "as long as you're in there". In very broad rough terms you should
get 2 chains and one set of guides per million miles of engine.

Signature

Need Mercedes parts ? - http://parts.mbz.org
http://www.mbz.org | Mercedes Mailing lists: http://lists.mbz.org
633CSi 250SE/C 300SD | Killies, killi.net, Crypts, aquaria.net
1970 280SE, 72 280SE | Old wristwatches http://watches.list.mbz.org

Reply to this Message

Martin Joseph - 05 Feb 2005 20:41 GMT

>> I have heard that at a certain mileage it's a good idea to replace the
>> timing chain guides (which are plastic). However, I am not sure whether or
[quoted text clipped - 8 lines]
> (edited by marty) changes
> were kept up.

<snip>

That might be true, but in my experience 100K miles is the right time
to replace a timing chain in most vehicles. Usually at that point
there is enough wear and tear to make this replacement a good idea.

Marty

Reply to this Message