Hi Guys:

I was just reviewing some repair documents that were furnished by the previous owner when I bought my car (back in February 2000). Back in August 1996, one Repair Order (from MBZ West -- Specializing in Mercedes Benz) shows the timing chain AND tensioner being replaced at 67,436 miles.

[1] Timing Chain $30.00
[2] Timing Chain Tensioner $380.00
[3] Install modified tensioner $200.00 (labor)

The Order does not say anything about Chain Rails being replaced, so the questions are:

[a] What was/were the problem(s) associated with the "factory" chain tensioners? I heard it was one of lubrication, and also heard one could modify the existing by drilling a small oil passage hole (?)
[b] Are there inherent problems with factory chain rails, or were they failing because factory tensioners were not being changed?
[c] In your opinions, at 67,000 miles on the factory tensioner, will that have created any problems with the rails? FYI, the new tensioner has been in place 20,000 miles and I have not seen/heard any problems.

Also, what indicator(s) can I look for to see that the tensioner is, in fact, the "upgraded" version?

Thanks!

Brian16V

Benzmac, MB Doc:

Where are you guys

Thanks!

Brian16V

Nowhere near Campbell. I've heard nothing but good things about Patrick Tan at Mercedes Select Service in Milpitas.

Sixto
91 300SE
81 300SD

The rails only failed on engines that were overheated or the oil was never changed in. Aside from that, the rails would hold up past 120k miles with the new tensioner.

The difference was in the way the tensioner behaved on initial start up. The old tensioner relied on a spring to hold tension on the bow rail while the engine was trying to produce oil pressure during cold starts. The spring wasn't strong enough and many of them failed and the engine jumped time.

The new tensioners have a ratchet device that will not allow the piston to go back, therefore the likelihood of chain failure is greatly reduced.

I installed one in my 16v at 118,000 with no ill effects.

__________________
Benzmac:
Donnie Drummonds
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS

Thanks Benzmac! Your reply makes me feel a whole lot better. Judgning from the stack of service records I got with the car, my ride has been well taken care of (I've put on less than 1,000 miles in the past 2 years).

Thanks again.

Brian16V

Well I get a rattle in the morning, and it goes away pretty quick. I was told that its the timing chain. I heard there is an update out there, but I figured my car would already have it being a 93. Its never been replaced yet, so here are my questions:

I am leaking a little oil from the timing cover, and now I have to the chain (should have just done it when I was in there at 90k.) But anyways,

I know Bekker has a Timing Chain Tensioner Update kit for $298, does MercedesShop or anyone else? Does this kit include the tensioner which normally goes for about $30.

Should I replace the guides/rails while I am in there, seeing as they cost less then $4.00 each.

I was deff replacing the timing chain, since its under $35. I mean anything else I am missing here?

__________________
Chirag (Charlie) Patel
--------------------------------------------
- 03 Mercedes S600 Sport TTV12
- 97 Acura NSX-T
- 99 BMW E36 M3 w/500+ HP
- 04 Lexus RX330
- 04 Dodge Dakota Quad 4x4 V8

4 Sale:
- 99 BMW M3 E36 Coup with Dinan SC, Upgraded to an RMS Stage 3 with Aftercooler, 12psi, and 500+hp @ flywheel.