I took the car to my Indy and told him about this problem, he says he's going to open up the valve cover and check if the timing chain is loose or not (if there's any slack or not). He said he would like to do this as opposed to just replacing it. Do you guys think this is a good enough way of diagnosing if my chain is stretched or not? Also, the original MB Timing Chain is $300, but I found an IWIS branded one online for $60. Is the IWIS comparable to the MB one? Or is it of cheaper quality? Also, has there been any update to this chain? Or should I just replaced it every 100k miles?
Thanks for the help!

 

The IWIS is probably fine. Pretty sure there are some on here that have gone with it, they can chime in on their experience.
If you aren't hearing the start-up rattle, you may not see any slack in the chain. How many miles on your car?

 

I'm hearing something just like lilbenz230's video.
It's at the shop right now and will be opened tomorrow for inspection. The car has 95k miles, I am just having it looked at because of what I've read here. Other than that noise, the car has no symptoms? Thanks for your time guys!

 

I was told that IWIS is the OE-supplier, so it's the same chain. I miss my 05.

 

change your oil using 0w-40 that noise that startup will go away. your engine is fine your only going to hear the chain hit the case for about 2 to 3 seconds as soon as the engine starts. I have 90k miles and im still going to change the chain and tensioner

u ever use techron fuel cleaner or redline?

 

I used the IWIS replacement chain, and the oem one I took out was also stamped with the IWIS logo.

 

Thanks KillerP - I actually started a thread asking this question, as IWIS is supposed to be the OEM for the chain.

Edit: Must be a lot of folks doing this - the IWIS chain seems to be out of stock pretty much everywhere...

 

So I finally have a break to post back. Over the weekend I had the cover pulled to check the timing chain and guides. I was prepared to change the chain and tensioner and I was quoted about $500 for the job with parts. Upon inspection the chain was not loose and was very tight. I tried to push down on it with my hand and it did not budge. I also looked around for wear on the links and the brain looks brand new. The car has a total of 95k miles on the odometer. Oil changes have been from what I see every 10k miles for the first 85k miles with the previous owner and every 5k miles with me up until now. I took advantage and replaced the valve cover gasket and the o-ring for the vacuum pump that was starting to leak. No visible oil leaks whatsoever. I just sealed it right up and decided it was all fine. Here are some pictures:

 

jpman - are you saying you pushed down on the chain at the top (on top of the brace)? I think you (we) need to be looking at the chain tension or slop on the 'tensioner' side. If the chain gets too stretched that the tensioner can't keep tension in the slack part of the chain you have the situation where it can skip a tooth. I assume this is also where the noise at startup would be coming from - chain is too loose for the tensioner to hold it tight, so the slack chain rubs against the engine.

See Hogger's post #7 in this thread - see how the chain doesn't go straight between the guide and the cam gear? That's the slack - the chain is loose there and the tensioner can't keep everything tight.

I need to go on a business trip in a week, so am going to try to take care of this in the next few days ...

Can you clue me in to the o-ring on the vacuum pump?

 

BTW, I got the iwis chain. I have no problem using OEM parts, so long as they ARE really the OEM part. Not so sure here... All looks good, except there are no holes in the link pins like in jpman's picture. Do all the original timing chains have these holes (I assume for helping lubricate)?

I haven't taken the cover off my car yet to check mine and haven't decided if I'll use it or not. Thought I'd post for posterity. maybe someone can post a pic of a NEW(replacement) genuine Mercedes chain (please)?

 

So I started on this job - probably going to take several weeks because I'll be out of town and just working in between. Biggest pain so far was having to take the intake/MAF out to get enough slack in the coil wires to wiggle the valve cover off. Oh, and there are a bunch of zip ties you'll need to cut to separate wires from the valve cover that aren't mentioned.

Everything seemed tight at first and so I was wondering about letting it go for a while longer. Then after poking around for a bit I found some looseness right where the screwdriver is in the pic below (the part of the chain between the guide and the exhaust cam gear). I'm going to crank the crankshaft a bit to see if the slack gets worse in that spot.

I think I am going to replace with the IWIS chain because I'm this far along. I'm a bit bothered by the fact the replacement IWIS chain doesn't have holes in the main links and the factory chain does. Hogger's pics show both his factory and the replacement without the holes and the IWIS is supposed to be OEM so even if I order a genuine MB I think I may get one with no holes (maybe not... anyone?).

I'm at the point now where I need to take the serpentine belt and alternator off. I'm going to replace the serpentine belt (still need to order) and also will be ordering the assembly link to help pull the chain thru per the instructions (wish I had read them more thoroughly). I'll try to take more pics as I progress.

EDIT: A bit confused - in the first few of Hogger's timing chain pics it shows a chain with holes in the main links. In the latter chain pics (comparing the new/old showing chain stretch, and new chain installed) there are no holes in the links. I believe Hogger used a genuine MB replacement chain - Hogger?

 

Killerpancake - did the new/old chains have the holes in the main links?

 

mtnman82,

Sorry for the delayed response. I checked both the side and the top part of it. I believe very little slack on the tensioner side is normal. It cannot be completely tight all the time. That is why there is a hydraulic tensioner in place. The slack it had on the side (where the tensioner is) was maybe an eight of an inch in movement. But the engine was cold when I tested this. With the tensioner completely filled with oil once started I can imagine its duty is to tighten the remaining slack.

I believe that as long as you do not have any slack at the top part, it is not necessary to replace this at the moment.

We keep reading that these cars are horrible with the chains and that it is their weak point. However, we have to consider that the cases that we see are all here... out of the thousands that were produced I can only think there are some isolated cases (in these forums the majority of what is posted is regarding problems).

My indy was going to charge me $500 to replace the chain including parts. He advised me against it once he uncovered the valve cover and checked for tension.

Regarding the vacuum pump seal, my indy replaced the valve cover gasket because some oil was present by the spark plugs, and on inspection he noticed a little oil by the vacuum pump that sits in the back of the engine. He took the pump out cleaned it, replaced the o-ring that is sold by mb and put it back together.

 

IWIS is the manufacturer of the MB chains. I have seen both personally and they are made by the same company. They also make high performance timing chains and make them for bmw M variants and Mercedes AMG's as well. Very good stuff.

I would put my money on it being a refreshed model chain. That is the original stuff you have there.

I wish they offered something like this for our cars.

http://www.ecstuning.com/BMW-E46-325...ing/ES2592851/

 

Hogger,

The noise I hear sometimes is only when the car has been sitting for a couple of hours. Sometimes it does it, other times it does not. The noise mine does is similar to yours when you started the car after you swapped your timing chain.

In your own video it is from 1:06 to 1:11 its also the one that seems to have a spike in noise at around minute 1:09. Weird thing is yours does it with a fresh timing chain.


Which also happens to be the same noise present here.


Hogger can you verify if the noise you had before swapping the chain similar to the ones I show above?

 

I'm not 100% certain, but I would think mine did it because everything was re-built, re-done, and new. The new tensioner never had oil pressure to it since it was a first start, so it rattled a bit.

I'm just guessing that's the similarity.

 

Hogger, could you record a cold start with the new chain/tensioner just for the record?

 

Even better, can people just start posting cold start videos of there cars with mileage and oil interval change. I have a strong feeling that oil change history has a big effect on chain stretch.

 

I'll get one in a day or two. I think we might get over freezing tomorrow.

 

It's about 15 degrees out, it's a real cold start. My battery is a bit weak.

 

Here's my startup video. This was done at 84 degree weather. The noise I am referring to is between the 12 second mark and the 15 second mark. I am beginning to think the noise comes from the cam adjusters.

 

Here is mine....temps in mid 40s, car sat for 10+ hours, overnight temps low 30s...about the 35 second mark begins what I suspect to be the belt tensioner rattling. Noise goes away when warm. I have removed the VC and inspected the chain, it's taut with very little play, pics on this thread.... https://mbworld.org/forums/c-class-w...hain-pics.html
Pardon the leaves!!! Can't keep up!!
https://www.youtube.com/watch?v=qWdq...ature=youtu.be

 

The noise you hear around the 35 second mark is a lifter noise. I get the same noise depending on temperature, sometimes it does it, sometimes it doesn't. It goes away after a couple of minutes.

 

Everyone please change out your chain tensioner first before you go do a big job on a chain swap. Most likely that chain tensioner is really weak. It's located behind the alternator. When mine jumped my chain wasn't even stretched compared to the new one.

 

RWDlifer, I kinda have the same noise as yours at 0:11 - I thought that's the chain rattle everyone is talking about...