cracking noise from a new 320 CDi engine - cracking noise fr

[John Walley]

I'm looking for some advice regarding an unusual cracking noise from a new 320 CDi engine plus consumer rights...

I bought an new E320 CDi estate last September and noticed a peculiar knocking/tapping/craching noise in November. The noise is apparent when then the engine's hot, windows are down and the car is cruising along at around 1000 RPM.

When I took the car back to the garage I bought it from they said they hadn't heard the noise before and would investigate. The car's been back 3 times now and after the last visit (car booked in for 3 days to take the manifolds off and "get to the bottom of it" ), the garage showed me a document from Mercedes which indicated that this is a known problem related to number 1 cylinder.

Under light engine load, with the windows down, between 1000RPM and 1500 RPM there's a cracking noise eminating from the first cylinder. There is currently no solution to the problem and it wasn't clear what caused to problem or whether a solution was being worked on.

I'm concerning about long term damage to the engine and the effect the noise could have on resale value.

Since then the garage have suggested I pursue this further with Mercedes and vica-versa. I'm getting nowhere...

I'm looking for advise on a number of issues please:
1. Has anybody else come across this problem?
2. Does anybody know what's causing it?
3. Is it likely to cause long term damage to the engine?

4. Who should I take the matter up with, the garage or Mercedes.

Any advise would be greatly appreciated...

 

[MikeAllan]

E320 CDI

Hi, I too have had this problem and have to date received no satisfaction from Mercedes other than to say it does not affect engine reliability, but as you are probably aware, driving in multistorey carparks can be extremely embarrassing. If you still have the car and the problem drop a note and I can tell you my full story.
Regards

 

[John Walley]

Mike,

Mine's not a happy story.....

After 6 trips back to the garage Mercedes finally agree to replace the engine. That was back in April.

The replacement engine was fine to begin with but after a few 1000 miles I started to hear the cracking again. It was very faint though and not at all obtrusive, If I hadn't heard the terrible noise from the first engine I doubt whether I'd have noticed the noise in the replacement. It didn't get any louder for the next 10,000 miles then.... disaster.

Major banging noise from the engine, clouds of white diesel smoke and the engine barely ticking over. The dealership dismantled the engine and sent the con rods, crankshaft etc away for investigation. Meanwhile they tried the injectors in another engine and guess what - yep, it made the same banging noise. They rebuild the engine, replaced the injectors and after 5 weeks the car was back on the road. It could have been a simple injector fault all along.

That was 2 weeks ago. The rebuilt engine was running fine and interestingly there were no cracking noises. I would go and try the engine right now but the car's off the road again till the weekend while a fault in the air bag control system (SRS) is being fixed.

I bought the car 14 months ago and its been in the garage 9 times and off the road for over 45 days..... Great car when its running.


Back to your problem..
I've heard a theory that it could be due to the lower temperature of the combustion chamber of number 1 cylinder which is at the front of the engine. Rechipping may be a workaround to the problem, it would be interesting to hear of people's experiences, maybe the tuning companies could advise.

I've heard the cracking sound on several E320 CDI engines in car parks and in high streets, the noise doesn't seem the be that uncommon.

I'd be inclined to ask for another engine, Mercedes acknowledged there was a problem by replacing it the first time. If there was a simpler solution I'd have thought Mercedes would have tried it. These types of problems can be very subjective though.

Good luck.
John

 

[MikeAllan]

Thanks for the reply it sounds as if you have your hands full with your car!
I managed , yesterday, to persuade my dealership to ask the tuners Brabus to send me a chip to try out, and if successful I would then purchase it, still awaiting the response. At least Brabus warrant the engine then and you are not left high and dry should things go bad.
I will post a message on developments.
cheers

 

[piestore]

320 cdi Engine

Yes this is a characteristic of the engine they all do it to some degree, I believe that MB have identified the cause and there is no fix. MB have stated that there is no detriment to the engine in wear or performance. My best advise is put up with it. If you continue full MB service history and you have an engine problem they have always looked on goodwill cliams very favourably.

Warning Brabus will provide a chip kit that does improve performance it does not solve the noise problem and it does invalidate MB engine warrenty and NO Brabus will not replace Blown engine.

Note that MB have now developed a new version of this engine which does not have the noise.