Rattle on cold start up.

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My experience of these is:- I have had 4 cars with chains

1. Nissan Primera 2.0eGT awesome car no issue with chains even at 160K miles when I sold it
2. Ford Mondeo st24 v6 - no issue with the timing chains well past 100K
3. Honda accord 2.4 vtech which revved to 8.5Krpm, no issue with chains well past 100K
4. Merc c250 cdi, chain started to fail at 90K with a loud rattle at start up..

I have had at least 10 or more other cars with belts which have never caused a problem. I look after my cars and change all service items well before they are due.

The Merc is the first car I have known to have a chain issue with, but it was sorted easily enough......But it does seem to plague this brand more than some. My thoughts and others may argue otherwise.

Maybe its just luck of the draw??
 
Mercedes do have a poor reputation for timing chain problems but they are not alone. BMW amongst others have had similar issues. Much of the problem may be due to the move from duplex chains to single row chains, so it's not that manufacturers don't know how to make an engine reliable, they trade reliability for headline mpg and emissions figures which is sad. On top of this some manufacturers put a chain at the back of an engine to make things an order of magnitude harder and more expensive which just beggars belief.

My preference for a belt is that it's a much easier DIY proposition, I've done it myself and it's a breeze on a longitudinal engine. FWD is bit harder as there is usually an engine mount in the way.
 
The telling thing is that - in all my years of Mercedes ownership - I’d never heard of any timing chain issues whatsoever until the more “modern” engines came along.

And they call it progress...
 
To be fair i think the old m116/m117 engines had issues when they used single row chains(might have only been the US).
They also had issues with the chain guides failing with age.

I imagine there is a trade off between making the smaller engines light and efficient vs durability
 
It's going in on Mon, 21 Sep. for investigation. No doubt they will say it needs timing chain, gearbox, back Axle, a couple of Ashtrays, Boot lid, radio, Front Carpets, and Fluffy Dice replacing. The bill will of course be a suicidal inducing equivalent to the national debt. Oh well happy days.
 
It's going in on Mon, 21 Sep. for investigation. No doubt they will say it needs timing chain, gearbox, back Axle, a couple of Ashtrays, Boot lid, radio, Front Carpets, and Fluffy Dice replacing. The bill will of course be a suicidal inducing equivalent to the national debt. Oh well happy days.


LOL, sounds like a standard quote for work from a main dealer that.
 
The telling thing is that - in all my years of Mercedes ownership - I’d never heard of any timing chain issues whatsoever until the more “modern” engines came along.

And they call it progress...


Its the sad truth of the modern world, cars are deisgned and built for maximum profit and not customer satisfaction or reliabilty...

Modern cars are sold almost the same way as a mobile phone contact, as long as they last the life of the pcp contract nothing else matters. or at least thats the way it seems to me..
 
I think your right about the move to chains, The complex timing/variable cam timing system is only possible on some of the newer deisgns using a chain...

All I know really is the cost to replace a belt was small, a chain is not cheap.... Happy days..
The part may cost more , but in general a chain can be split and a new one wound in , with a lot less disassembly and labour than a typical belt replacement.
 
The telling thing is that - in all my years of Mercedes ownership - I’d never heard of any timing chain issues whatsoever until the more “modern” engines came along.

And they call it progress...
Depends what you call modern .

Rattly timing chains were not unheard of on the M180 series ( as fitted to my Ponton and in service at least up to W114 , think they may have crossed into early W123s before the M123 came in ) , M130 ( I’ve been in a Pagoda with a rattly chain ) ; M115 - the chain tensioners in my dad’s 220/8 went weak ; M102 ( early ones with single chains , later duplex ones less prone to issues ) .

None of this is at all new , but it is quite a simple job to split a worn chain , join on the new one and wind it in by hand , requiring only removal of the cam cover . Often tensioners can be replaced at the same time from above .
 
As it is only rattling on cold start, are you not sure it may be tappets with a poor oil flow to them when cold? I have owned quite a few Mercs and have never had a timing chain issue, I do remember having to change one though on my 850cc Mini :D
 
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As it is only rattling on cold start, are you not sure it may be tappets with a poor oil flow to them when cold? I have owned quite a few Mercs and have never had a timing chain issue, I do remember having to change one though on my 850cc Mini :D
I’ve had that with hydraulic tappets on a M103 , but a different sound entirely to a rattly timing chain , more of a tick , tick tick which lasted for just a few seconds , and usually only at cold starts .
 
As it is only rattling on cold start, are you not sure it may be tappets with a poor oil flow to them when cold? I have owned quite a few Mercs and have never had a timing chain issue, I do remember having to change one though on my 850cc Mini :D

Chain rattle is quite different to noisy tappets, it's a definite "Rattle"
 
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The telling thing is that - in all my years of Mercedes ownership - I’d never heard of any timing chain issues whatsoever until the more “modern” engines came along.

And they call it progress...

To be fair, in the olden days many car manufacturers used a simple design to ensure reliability and durability.

In the late seventies, a friend had VW Golf (they were the most reliable cars on the market after Volvo and Saab at the time), with a 1.6L engine that produced 75bhp.

The Alfas of the era produced 109bhp from a 1.6L engine.... but with the Alfa engine having a DOHC design with aluminium head and block, guess which engine was more reliable....

So part of the issue is that modern emissions regulations mean that we now have highly-stressed low-displacement engines doing the the same work that 30 years ago was leisurely done by engines double the size.
 
I'd argue that it's not the specific power output per litre that is the direct cause of unreliability with modern engines as we don't hear of problems with the bottom end which are usually good for several hundred thousand miles. It seems to be valve gear whether that be chain and sprocket wear or the complexity of the variable valve timing mechanism. In the search for lower internal frictional losses, manufacturers have deliberately under engineered timing chains which they once knew how to make durable.
 
That’s what I paid at a very good MB specialist.

That seems a good price, for Chain, Sprockets, and Tensioner replacement, how long ago was that and where did you have it done ?
 
Dropped the car off today, bloke says there is a couple of updates due nox sensor is one plus ecu and g/box. But I have heard of people finding fuel consumption not as it was before the updates ie. A fair bit worse. So I have told them not to bother with nox sensor update. Has any one on here had nox sensor updated and realised a drop in fuel consumption ?
 
They say it needs a new chain and tensioner, can anyone recommend a decent indy around Sheffield ?
 

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