94 E320 - when do u change timing chain?
 

My e320 is coming on 94K miles and I was wondering when do I need to get the timing chain replaced.

Many thanks,
CM

That depends....
 

If it is a metal chain, then it should be changed at 90K to 100K. :D

But if it is a rubber belt.... 60K to 70K. :eek:

That is what my knowledge tells me, I am sure you already know this, but just in case you don't...

If a timing belt/chain were to break, the valves hit the cylinder heads causing servere damage. :pukeface:

Please make sure that you change it, but only by a competent mechanic or yourself if you trust that person in the mirror. :)

Your car has a strong double row chain with a short run from the cam to the crank.

On the M104 I would not say it is necessary to change the chain at 100k miles just for the fun of it. If the engine has been cared for and had regular oil changes, the chain should really last much much longer than 100k miles.

That being said, a check of the chain stretch will determine if the chain needs to be replaced. This is what you should use to determine if the chain needs a replacement if you are worried about it.

The double row chain on the M104 engine is very stout and with frequent oil changes can last a very long time. I have seen M104's and M111's (the four cylinder cousin to the M104) with 300,000km's (190K-miles) or more on the original chain without any noise from the chain.

A mechanic can check the chain for stretch by measuring the change in cam timing.

The only Mercedes engines I would change the chain as early as 100K-miles is some of the V-8 models with very long chains with severe direction changes. Also, some of the V-8's (especially the M116) have plastic guides that age badly.

I just had mine changed on the '94 wagon with 238,000 miles on it because it was 'a little slack'. I drive a lot and pretty much change my oil every month. I didn't know it is a double chain though :o . I know the wife's '99 E300 is double chain.

Drove my 1990 300E to 175K on original chain. I just had the chain replaced on my 1992 300E at 214K. I bought the '92 at 100K and have run it on Mobil 1 with changes at 3 to 5K, 95% long Interstate trips.

There was no noise, but thought it should be done. If you are changing the
oil and filter regularly, why worry about it?

Steve

That's what I thought . . .
 

. . My wife's Honda has 92K and the 'book' says change the timing 'belt' (no chain on a Honda!) and it broke last week when she was about a block from home.

The good news, BION, there was no damage. . . . The tech said to me ". . you go buy a lottery ticket". I did but I already had my luck for a long time.

On the Lexus LS 400, the timing "Belt" change frequency is 120,000 miles.
On a Nissan Maxima the timing "Chain" life is 200,000+ miles.

If Mercedes Benz timing "chain" needs to be changed after 100,000 miles, then it is a poor design, similar to other poorly desgined area's like radiator neck, AC Evaporator, Head Gasket........

Many thanks
 

The information you all provided was very helpful. The car is getting dropped off next week for the regular 3K miles oil change and I will have my "trusted" mechanic take a look at the chain.

Cheers,

CM

For what it's worth, I'm currently in the middle of replacing the head gasket on my '94 E320. Since there's no rush I thought I'd use the time to re-condition the cylinder head. I stripped the head down and left it in the cleaning tank over the weekend. It looks like a new casting now. I machined the valves/seats just for fun ( no visible wear ). I checked the deck mating surface for flatness and found it well within spec. I also checked the guides and found no measurable wear. I thought I'd find at least a few degrees of stretch when I checked the chain but it was fine. I lapped the valves in and re-assembled the head. It's mostly back together now. I'll finish the job this weekend unless something important comes up. Now back to the original question. I wouldn't replace the chain just for the heck of it. If we were talking about M116/117, M103, or the 603 diesel I'd think otherwise. The 104 wasn't known for bad timing chains. Since the 104 came out in the early 90's I've only seen a handful of bad ones.

If you feel you must change 'something' at 100K...do the chain tensioner. Just my 2 cents. :)

Yes.
If you have to change something , then change your mind.
If there is anything a 104 is famous for, it's top end and chain longevity..
200k , no problem.. not even valve guides

I have a '96 E320 and my MB mechanic & dealers told me that the timing chain will last >200K miles

[QUOTE=ILUVMILS] If we were talking about M116/117, M103, or the 603 diesel I'd think otherwise. QUOTE]


The 603 really should not be put in the same catagory as the V8's. On the diesels you change the chains because they stretch and your mileage and performance degrade. However they should last 300k+ miles before I would even think one might break. The newer 606's I would venture to say almost never need the chains done, maybe at 400k.

I have 244k on my original chain but I will do it soon just for the heck of it.