PeachParts Mercedes-Benz Forum

PeachParts Mercedes-Benz Forum (http://www.peachparts.com/shopforum/index.php)
-   Tech Help (http://www.peachparts.com/shopforum/forumdisplay.php?f=1)
-   -   Timing Chain Fears (http://www.peachparts.com/shopforum/showthread.php?t=6777)

tahodgson 03-19-2000 05:53 PM

I'm new to Benz ownership, buy my 1987 560 SL isn't new...about 101,000 miles. Have heard scuttlebutt that this is the time to have the timing chain checked. The car has just recently begun to run a little rough...and I haven't yet gone over the ignition system.

Please give me the straight scoop on the "Timing Chain at 100,000 Miles" ledgend.

...and confidential to Benzmac...was in Atlanta last week...should've stopped by and bought you a cup (or bottle) for all you do for the folks here in this forum!

pmjs 03-19-2000 06:20 PM

at 101k miles either your a lucky man or most likely the chain has been already replaced earlier.the chains and 4 upper rails are in need of replacement usually at 6ok,like clockwork.Recommend removal of both valve covers for inspection.what happens is the chain stretches and then slaps the chain rails.this can happen at start-up and while driving.rather be safe than sorry,have it checked.rec replace chain tensioner too

[This message has been edited by Webmaster (edited 03-20-2000).]

stevebfl 03-19-2000 06:42 PM

I have overseen the repair of at least 200 single cam MB V8 chain failures (3.5/4.5, 3.8/5.0, 4.2/5.6).

Here is the story; The number one cause of failure (9 to 1 atleast)is the fracture of petrified chain rails. The rails in the upper head do not normally touch the chain. When they are new they are opaque white plastic. They are indestructable. After 70-100k they turn brown and become as brittle as glass.

Now comes the sweet part; even with various tentioners and modifications MB could never 100% not loose the oil pressure in the tentioner. They just rattle every once in a while. Its a shame they never put a ratcheting tentioner in, but I'm sure they had their reasons. This rattle (you can't prevent it) breaks the old rails like glass and the pieces run through the meat grinder bending all the valves in the left head. Just like clockwork.

My recommendation is new rails every 60-80k. It is only about a three hour job and the rails are less than $5 a piece. Do a chain if you want but it won't fail on its own. After 150k you will have about 10deg retard in the passenger side cam due to stretch but we used to use offset keys to tune that out. This is factory method they couldn't have been too worried, originally. Thus my total recommendation is a chain before 200k and as many rails as necessary to keep them fresh.

Now for the second life. The bottom right side rail rides on the chain and will wear through at around 300k; so if you are in the neiborhood with head work or chain repair take that into consideration. This rail requires removal of the front timing cover about an extra 12-15 hours work with a head job. About 20 hours or more on engine with the heads on. We charge 40 hours to do heads and front timing cover on 107 SLs where the subframe and oil pan must be removed.

------------------
Steve Brotherton
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician

arosen@troweprice.com 03-19-2000 06:51 PM

I just bought a 1991 300D with 160K on the clock. Before I begin to have nightmares about the timing chain, what is the scoop with the timing chain on my little diesel?
Again, THANKS for all of the time everyne has put in here answering my questions.
ARI

mbdoc 03-19-2000 07:06 PM

Diesel chains are stronger than the gas models, but 160K miles is long enough. Don't put off replacement.

arosen@troweprice.com 03-19-2000 07:57 PM

I ahve all the records for the car, but I do not see anything with regards to inspecting/replacing a timing chain. Do you know what MB recomends to inspect/service the chain? Do you knwo what it should cost (roughly) to replace this?

Robert W. Roe 03-19-2000 08:55 PM

I had my mechanic check my timing chain stretch. He measured it at 3 degrees and said 5 degrees is replacement time. With 169K miles on my M617 diesel, how much time do I have left?

------------------
Robert W. Roe
1984 300SD 169K mi

arosen@troweprice.com 03-19-2000 09:02 PM

When I take my car to the mechanic on Wednesday, is this measurement procedure something that can be done why I wait?

chaudo 03-19-2000 09:20 PM

This is an interesting topic. I have a '90 300SL with 190 K. I recently brought it to a MB dealer and enquired as to whether the timing chain needs to be inspected and was advised that it there was no need for this service.

Given all of the problems and advice that I've read in this forum, why is MB so stubborn about insisting that that timing chains service is unnecessary?

Also, I need to repair my AC. Does anyone know of a reputable independant MB tech. in the Toronto, Canada area? I would appreciate any recommendation because I am not entirely convinced that I am getting value for the service provided by the dealer. Lastly, does anyone have any experience with non-OEM AC parts or rebuilts for an AC, if such parts exist?

arosen@troweprice.com 03-19-2000 09:33 PM

I know that there are several reputable MB techicians that monitor this site, let's see what they have to say. So far they have been right on all of my other questions.

Aaron 03-19-2000 10:55 PM


I don't know if any of you saw one of my more recent posts, but I just had to do a new chain and all upper rails on my '85 380SE. I had been experiencing a rough idle for some time. I replaced everything in the fuel injection circuit and still no avail. Finally, when I had the day off from the shop, I decided to pull the valve covers because I was suspecting the left cam of not being timed properly. Sure enough, the left inner rail was broken into pieces! I was sooo lucky that it didn't destroy my engine, but I caught it right in time. Car has 110K miles on it and as I am writing this, I am on vacation in Atlanta, GA and drove the 380 here and it ran beautifully all the way at am average 85-90mph loaded down with luggage and four people. In the meantime, my 420SEL is still sitting in the stable at home awaiting major top end work, because the same thing happened to that car but unfortunately I wasn't so lucky. That car has 102K on it. Will be pulling the heads as soon as the weather breaks.


------------------
Rgds,
Aaron Greenberg
MB technician
Precision Motorcars, Cincinnati, Ohio
'67 250SE Cabriolet
'77 450SL
'80 300SD
'85 380SE
'89 420SEL
'93 300E 2.8
'74 Jensen Interceptor Mk.III
'81 DeLorean DMC12
'85 BMW 745i Turbo

elau 03-19-2000 11:03 PM

I have a 95 SL320 with 64K miles, do I need to take it in and have my timing chain looked at? Someone told me the newer SL has two rows of chain and there is no requirement to change them ever. Can someone clarify this for me?

95 R129
98 ML320

arosen@troweprice.com 03-20-2000 06:40 AM

I think we need a great deal of clarification on what cars have what and when.

LarryBible 03-20-2000 07:47 AM

tahodgson,

If you do get a chance to get Benzmac a cup or bottle, send me the bill.

Larry

tahodgson 03-20-2000 09:01 AM

Well, I'm now almost afraid to drive it to the shop...but I'm certainly going to take it in. One good thing...I haven't noticed any strange noises upon start-up...but also admit that I haven't had the car long enough to learn it's "normal" sounds. (bought in November and almost immediately stored it until a couple of weeks ago).

Thanks, everyone, for your great advise and counsel (again).



------------------
Tom

'87 560 SL

stevebfl 03-20-2000 10:26 AM

I think there is way too much paranoia here. The only motors that give no warning are the single cam V8s. The diesels will rattle quite some time before failing. The noise should be apparent to those paying attention; even over the diesel noise.

The real breakthrough in confidence comes with all the motors with ratcheting chain tentioners. 102/103/104, 601/602/603,606. I presume the 119 motors must have a ratcheting tentioner but we haven't done any failures on those motors yet.

------------------
Steve Brotherton
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician

tahodgson 03-20-2000 03:50 PM

Thanks for the comforting thoughts...but, the rough running certainly merits a trip to the shop.

Is there anything obvious & easy that I should check in the meantime?



------------------
Tom

'87 560 SL
'74 MGB

arosen@troweprice.com 03-20-2000 05:46 PM

I decided to be safe and dropped my car off at Roy Fields (410.252.4101) and they are going to do the chain + tensioner for $375 total. From what he told me, the problem occurs more often where the chain stretches, then eventually jumps a tooth. Ouch!!
I know from working on our dragster, what a motor looks like when the valve train jumps at 11,500+ RPMS.
From experience, I have been there, done that and even bought a T-shirt!!
Thanks for all of yourt help!
ARI

arosen@troweprice.com 03-20-2000 05:49 PM

One more thing, with the 91 300D is it critical to replace the rails as well? I am under the impression that I am just getting the cahin and tentioner replaced, but not the rails.

Mark Herzig 03-20-2000 06:34 PM

When are you guys seeing replacements for the 603 300SDL?

------------------
Mark Herzig
1992 500E (86,000 miles)
1987 300SDL (110,000)



mbdoc 03-20-2000 07:31 PM

The M119 gas engine doesn't have a ratchet style tensioner, & yes they can jump & cause problems just like M116/117. The inner rail seams to break on this engine.

Most diesels dont need rails on normal chain replacement.

Benz issued a S.I. on all diesels from 7/92 thru 7/94 on possible chain failure. The only other engine they issued a bulletin on is the 1984-88 190E 2.3 8V, timing chain inspection every 60K miles is recommended.

------------------
MERCEDES BENZ MASTER GUILD TECHNICIAN
ASE MASTER TECHNICIAN
27 YEARS DEALER M.B. TECH
190E 2.3 ITS RACECAR
1986 190E 16V

Michael Haven 03-20-2000 08:52 PM

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Mark Herzig:
When are you guys seeing replacements for the 603 300SDL?
<HR></BLOCKQUOTE>

Mark I like to replace the 603 chain before 175k. I have seen 2 catastrophic failures on these engines and dont like to risk it. It will make a difference in the injection timing too, if it has not been adjusted to compensate for wear in the past.

------------------
Michael Haven CMAT,CMM,L1
MPH Automotive Services
16510 Park Row
Houston, Texas, 77084
281-579-8885

MB STARS 03-20-2000 11:35 PM

We just have a 1995 500SL with 119 engine tow in today guess what uper timing rail broken and driver side exh camshaft broken cause by the broken chain rail,vehicle just over 100,000 miles,have your check your timing chain and rails ?
ps. camshaft is $675.00 ouch!

------------------
MB STARS Master Guild Technician,12 years MB tech
6 years independent shop owner

arosen@troweprice.com 03-21-2000 06:47 AM

I think the moral of the story is, if you have any doubts about your timing chain, take your car to a reputable MERCEDES mechanic and have him/her look at it. I can tell you from experience that all cars operate with the same principles, but they all have their special points that MUST be understood by someone who lives, sleeps and breathes MERCEDES.
I have about 10 years experience on SCCA racecars, but that still does not qualify me to know Merecedes like the back of my hand.
After reading this borad I think we all know which people are seeing the big picture.
A big THANK YOU to everyone who has contributed factual information to this subject.
ARI

elau 03-21-2000 10:52 AM

ARI,
Notice that you are from the Baltimore area. Do you have any recommendations on reputable MB tech I can use? I have been taking my car to Benson in Annapolis, but they charge $69 per hour for labor. What bothers me most is the dealer insists that I should not worry about it since I have double row of chains. But then again my car is still under warrenty, so in case the chains do go, its not $$$ out of my pocket. BTW, I have 64K miles on mine.

95 R129
98 ML320

arosen@troweprice.com 03-21-2000 01:26 PM

I would use Roy Fields Mercedes. They are located in Timonium, directly across the street from the fairgrounds. The number is 410.252.4101, tell them ARI sent you from the internet.
They have been very good to me. I brought my 1991 300D in two weeks ago, before I bought it and they gave me a list of things it needed so I could deduct it from the price. When they started to do the work and pulled things off, there was $600.00 worth of hidden stuff that needed to be done, but I was not charged a penny for the extras, since they failed to find it on the pre-inspection.
I do not mind if a person makes a mistake, but I do mind if they try to hide it or cover it up.
Not so in this case.
ARI

tahodgson 03-21-2000 05:21 PM

Again, thanks everyone for such a complete discussion...I'm dropping my car off tomorrow...as I now reveal my complete ignorance:
What specifically do I ask the shop to do, without openning myself up to an enormous "search and destroy" bill?
Again, the car is an '87 560SL with 101,000 miles...and is there a relatively easy diagnosis for the cruise control? Or should I save that one for when the budget is a little less vulnerable?

A tip of the cap to all you professionals who contribute here....


------------------
Tom

'87 560 SL
'74 MGB


All times are GMT -4. The time now is 04:50 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website