There seems to be a ticking/clacking type of noise coming from under the hood when accelerating. It does not seem to only happen at any certain RPM but is most noticeable from 2k to 3k. I do not recall it happening when I first bought the car last year and I have always been very strict with the oil changes (5W40 Rotella T every 5k miles).

Now for the condition of the vehicle: I replaced the delivery valve O-rings a few months ago (clean EGR, new intake manifold gasket & O-ring) but I did not change the copper washers/seals. The lower control arm bushings are pretty shot so that is next on my list. I am fairly sure the engine mounts and belt dampener need replacing as well but I figure I'll do the control arms first.

A little bit of searching turned up this post which sounds almost identical. I'm fairly certain that the intake manifold setup on the poster's '85 500SL is not similiar to a 606 so I am wondering how likely I have the same condition.

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Scott C.

2006 E320 CDI (120k miles)
FOR SALE: 1998 E300 Turbo Diesel - Black w/Tan Leather - Euro delivery (236k miles)

Its hard to compare the sound without hearing it but my friends 606 would make a nice ticking noise when the turbo spooled up. Turned out the tubine blades were hitting the housing a bit, bearing failure. He swapped in a rebuilt turbo and all is well. He wasn't to happy about a MB turbo failing at only 160k miles but stuff happens.

Engine lived on various weights of Mobil 1 its whole life, 5k-12k mile changes.

Edit the belt dampener shock will make a ticking noise that almost sounds like a lifter sometimes. Replace it and see if the sound goes away.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

My 96 E300 makes a similar sound any time the engine is under load but not at idle under any circumstance. The link to the intake manifold post is interesting I plan to check that today. I suspect the injectors on mine I just have not had a spare $600 bucks to get the parts lately. I changed the belt dampener on mine it helped but that sound was different than the sound while traveling down the road. I too had changed the delivery valve o-rings and copper seals recently and have been wondering if I could have done something wrong. My engine runs and idles perrfectly which is quite puzzling. Keep us posted as to what you find I will be especially interested.

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Keith Schuster
2006 E350 98K miles
2013 Ford Explorer 15K miles

I've got a clack at idle to 1000 rpm after doing del valves. I did replace the crush washers and torqued to 35nm per the sticky MBDoc posted at Xmas time. The washers do not seem like they would make a tremendous difference to me but, I'm not experienced enough to argue so I replaced them too as the spec sheet stated. I did not replace the springs nor do I believe that most folks have done so.

Have you done a diesel purge? It helped to quiet mine afterwords. I plan to run my last two bottles through next week. I know you're a post collector and probably have CRMONT's how-to post. If not you can find it easily enough.

Do check the motor mounts; lift motor 1/4" max with floor jack and look for cracks on the tops of the mounts. Only takes 5 minutes to rule out.

Also check the fan shroud at different rpm's to make sure the fan isn't touching.

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

I would bet your nozzles, same on mine, get bosios or bosch same price around 200 bucks 1 hrs work and your done if you suspect nozzles!

Just to compare, this is my OM606 while idling (and revving), bonnet open and then closed:

http://homepage.ntlworld.com/tom.jeffs4/om606%20engine%20running.wma

Parrot

She is sounding sweet at idle now, did you give her the purge yet??

McCool300TD (230K)

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1988 190E Sold
1996 C230K Sport Sold
His: 98 E300TD Estate, 7 seater, Avantgarde, Silver, Black cloth, parameter steering, dipping rvm, folding mirrors, rain sensing wipers, pentagon tints, 17" Elegance wheels. 298K
Hers: 93 300TD, 7 seater, Grey MB Tex pearl blue metallic, 15" 8 hole alloys, OTG, Cruise, not much else 220K

Not yet. Doing the brake fluid and coolant this week.

Still very cold here.

The ticking stops if I ease off the throttle a little (wastegate opens) - the turbo is still spooled up pretty good but just dumping the boost, correct?

I've heard that a new belt dampener will wear out very quickly if the engine mounts are shot. I am hoping it is that easy and not something serious so that is going to be part of my new engine mounts job.

I did a purge right after the new delivery valve O-rings and it definitely quieted down the idle clacking. I think it was short lived however and it seems to be back after a few months. I only hear the ticking when the engine is producing torque - revving it neutral sounds just like yours Parrot. I'll see if I can borrow the video camera at my work and document the sound.

I am starting to question the condition of my injector nozzles anyway. I think a half-dozen of those Bosio's that DieselGiant has are in my future. Anyone know of a good source for some Bosch nozzles for a 606 turbo?

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Scott C.

2006 E320 CDI (120k miles)
FOR SALE: 1998 E300 Turbo Diesel - Black w/Tan Leather - Euro delivery (236k miles)

Funny thing this morning: During my usual "run it up to +4k RPM" at the end of my commute to work, I really did not hear the sound. The only difference is that it is 8 degrees Fahrenheit (-13 degrees Celcius)...

Frozen engine mounts? Tighter serpentine belt? Cannot be the nozzles, correct?

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Scott C.

2006 E320 CDI (120k miles)
FOR SALE: 1998 E300 Turbo Diesel - Black w/Tan Leather - Euro delivery (236k miles)