E320 CDI noise

[marcos]

Hi everyone, first post so here goes.

I am currently driving a E320 CDI W211 which is now nearly a year old. Since new it has made a horrible noise at low revs that sounds like the ticking noise you get with a blown manifold. I have spoken with the dealers and they have no idea. I spoke with MB in Milton Keynes and they are aware of the problem but have told me the noise will not cause any damage to the engine.
The noise is apparently caused by the crankshaft, and the noise is so prominent because it resonates through cylinder number 1 and the engine block is thinner at this part of the engine due to all the ancillaries so the noise escapes from the block.
Am I bieng taken for a ride by MB's and has anyone heard of this problem before.

Thanks in Advance

Marcos

 

[Brian WH]

Let us face it, the engine should not make the noise. It is still under warranty and you need it rectified. New engine if necessary, so play hell till they respond and /or write to MB.

 

[Dieselman]

Most 320 CDi version 1 engines make this noise. I thought that it was supposed to be under control on version 2 engines but possibly not on yours.

I may be wrong but I believe it's caused by combustion noise at low load conditions.

 

[marcos]

Dieselman,

The first explanation I got about this noise is exactly what you describe but MB have said its not caused by this.
I'm not sure about what to do. The car was a year old yesterday and several people said to wait the first year and see if the noise beds down, it hasn't, so do I demand a new engine or live with it.
You can only hear the noise with the window down driving between walls or parked cars.
Other than that the car is like a rocket and just perfect.

 

[Dieselman]

Ask for a more detailed explanation. Why should a crankshaft knock unless the bearings are worn, which I doubt they are.

The noise you describe does indeed affect most if not all 320 Cdi. Some owners have had new engines only for the noise to return on the new engine.

Try some injector cleaner before making any decisions.

I still think it's more likley to be combustion as I bet it doesn't do it when the engine is on the over-run and no fuel is being injected.

It might be worth having the timing checked to make sure it's not too advanced, also make sure no air is being drawn into the fuel system as that will cause cracking noises.

Probably nothing to worry about!

 

[Brian WH]

Whatever you try, make sure it is on Warranty and done by the Dealer, so as not to invalidate any later claims, for new engine etc.