E320cdi Tapping noise from top of engine

[MACHBUFFET]

Hi everyone
I was hoping someone could help peel me down from the ceiling here.
I have just bought a 2006 E320cdi Sport - facelift V6 model.
85,000 miles with full, proper and verified MB service history.
I have had the car delivered to my home and on start up, I'm hearing a noise I certainly don't recall hearing on the test drive.
It's a tapping noise coming from the top of the engine, toward the rear of the drivers side. It's a constant noise, almost sounding like a very loose tappet.
These engines if taken care of properly, surely shouldn't be into cam issues?
Having searched internet and this forum, another possibility seems to be injector related.
I have taken the engine cover off and been around with a mechanics stethiscope and had a good listen and the tapping appears to be from the area of the rearmost drivers side injector. Other people describe a chuffing noise but this seems to be more metallic tapping. I can't see all the way down to the injector due to some rubber moulding around the injector rail.
It's my first V6 so I'm not used to its sound. You can't hear it from the front of the engine, you have to be standing to the side and it isn't noticable above 2000rpm or from inside the car.
Happens from cold and stays same when warmed up.
The engine runs fine and idles well.
Any help or advice would be very much appreciated
Thanks
Barry

 

[sinewave]

If it's just been delivered then you'll have at least a 3 month warranty so have you informed the supplying dealer?

 

[panason1c]

Can you post an audio file of the noise?

 

[MACHBUFFET]

Hi fellas
No, warranty - private sale, so not an option I'm afraid.
Not the best on computers but I'll have a go with the audio file.
Thanks for the replies. Any more feedback greatly appreciated.

 

[GordonTarling]

Could well be an injector - take it to an indy or a diesel specialist and ask their opinion.

 

[mbenz1]

Try Liqui-Moly Diesel Purge, my fathers E280 CDI has tapping sounds when idling and accelerating, and most-likely its clogged up injectors so i'm considering using this product. many people have been impressed with the results. its inputted directly through the fuel pipe lines, which is why it does a much better job than fuel additives. it says on the bottle that it can be used for any diesel engine, so i assume it can be used in cdi engines aswell..

 

[prm]

Run some V-Power through it

 

[jumperjohn]

Run some V-Power through it

I second this advice!

 

[developer]

They aren't the quietest of engines (though accepting the noise seems new to you) and they do tick.

I wondered when I first bought mine, but it's been in the main dealer for warranty work etc a few times and I've had tech's stood over the engine with the bonnet up and not one has mentioned a thing.

As above, seek advice, but I suspect all is ok.

 

[camerafodder]

They aren't the quietest of engines (though accepting the noise seems new to you) and they do tick.

They are indeed 'ticky' engines. Best advice would be to take along to an indy even if just to set your mind at rest. Whereabouts are you? There are some good indys on this very forum that are scattered around the UK.

 

[MACHBUFFET]

Firstly, thank you to everyone who took the time to reply - very much appreciated and very helpful.
I've spent the last couple of days seeking some professional opinion and they've pretty much agreed with you guys.
Took to MB and tech had a look and listen and thought nothing out of the ordinary at all. Said that maybe one of the injectors was 'singing' a bit louder than the others but nothing to worry about and fairly normal for these engines. He did look a little bit like he was late for school though!! (perhaps I'm just getting older)
Today I went to an indy for a second opinion and he did the "smooth running" check. Hooked the car up to the computer and all injector readings, as well as all others, were completely normal and standard with no fault stored. He could appreciate the noise but again, said that this was fairly normal for these engines and they're all a bit chatty. He also suggested running some conditioner through as well but overall was very happy with the engine and saw no cause for concern.
Having just come from an E270cdi, it was a completely different experience and the E320cdi sounds a world apart from it and idles so smoothly and quietly by comparison. I think I just need to get used to its sounds and chat. Thing is, you have to stand at a certain angle / position to pick it out, so I think that perhaps I'm just being new car paranoid and my usual fussy self.
I'll give the V-Power a try though
Thanks again
:bannana:

 

[mobeyone]

The v6 cdi does sound totally different to the il6.

A friend has just bought a v6 c320 who also owns an il6 e320 and he cannot believe how different the two cars are.

Mine also sounds tappy and I've heard a few now who have a similar sound.

 

[bonez59]

I had the same problem on my e300td and it was the timing chain had jumped one tooth on the cam, pump and bottom pulley was spot on. Mercedes them selfs missed this, even when they put a new chain on. ( looking through the paper work)
Set the cam timing right and she stopped the tapping.

 

[MACHBUFFET]

Back again.
The noise is still there - really bugging me now. It seems to be coming from the area of the cylinder head on drivers side, closest to the bulkhead.
As an experiment I packed the area around the injector closest to the bulkhead temporarily and the noise quitened considerably, leading me to suspect injector noise.
As mentioned earlier, the smooth running test was fine but I'm guessing it wont point to physical deposits on the injectors.
I've tried a couple of tank additives but no difference. I saw a mention of a baring issue on the bottom end - what's this? This noise definitely seems to come from the drivers side, top of the engine. If I stand in front of, or to the passenger side of the car, I can't really hear it. Also, when the plastic cover is removed from the engine, the noise is lost mostly in the engine general diesel chatter - leading me to think the underside of the cover acts like an amplifier for the noise.
I've noticed also an occasional slight stutter at about 1100 - 1200 rpm when in low gear, low speed. Would this be injector related as well.
No fault codes found on STAR.
PS - anyone know where I can get a workshop manual?

 

[MACHBUFFET]

Hi Guys - tapping now much improved.
It's a long story but here's a link to another post where I've done a write up.

http://www.mbclub.co.uk/forums/engi...problem-please-help-anyone-2.html#post1434984

Thanks to all for taking the time to reply, I hope it's of some help.

Barry