Hmm... the sounds sure sounds like it is coming from the back of the engine compartment.

I heard nailing dscribed as usually a lower pitched sound, this is definitly a higher pitched loud, random (but very loud and often). I tried getting a sound clip of it, but it's hard to hear in the video.

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1981 300D 205,000 mi.

one guy on here found a rock or a nut in the bellhousing that would ping around off the tc and make a pinging click...

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

I am having the very same noise from my 78 300D - 157,600 mi. this sound occurs at acceleration up to higher rpm's. It sounds just like floating valves or lifters in a gasoline engine when the hydraulic tappets are worn out.

I am a Bio Diesel Process Designer and 30 yr. veteran of electrical and mechanical machinery troubleshooting. As well as an ex-Jet mechanic, i am fixing this car for my wifes everyday driver.

This car has absolutely no vacuum leaks and all devices are working properly at this time, this should rule out vacuum as a problem, even the door, trunk, and gas tank vacuum system is working fine.

I suspect the problem to be fuel injectors, as this car was ran on WVO for quite sometime and probably has coking issues within the fuel systems.

My plan of attack is : All filters first, then timing chain stretch check, then rebuild all 5 fuel injectors, etc. I will be posting as i cure out this issue.

KLG - I hope this helps you with your issue.

Did anyone ever come up with a solution to this noise? Mine is starting to do it too. Pings under load and more when cold. At operating temp it all but goes away. Very seldom makes a knock but when cold it does it quite a bit.

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http://img212.imageshack.us/img212/5...andbenzqj3.jpg1979 W123 300D Silver with Blue interior

Dead Thread? I've got the exact same problem on my unknown, but high mileage 240D...at 65mph+ it pings at a real high frequency at any throttle position. I figured the values may need a fresh adjust after my italian tune up, but I was also wondering if I was starving it of fuel from a bad injector.

No other recent changes on the engine/fuel front... It did just make a 500 mile trip just fine though!

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05 E320 CDI
99 SL500
02 530i

82 240D SOLD
83 240D Euro 4spd SOLD
86 300D Euro Auto SOLD

Sounds like a bad injector to me but it certainly wouldn't hurt to do the valves and check the timing stretch when you have the VC off. After I adjusted mine I noticed it was significantly quieter and smoother. Your problem sounds a lot different than the OP's...same goes to the guy who posted above you (textbook injector nailing).

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TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth

Sorry for the all too quick post. It certainly doesn't seem like nailing, it is entirely load independent, and happens cold or hot! Even slight throttle creates the clicking/pinging, full throttle makes the same sound.

I'll check the stretch, although the answer will probably not be a good one. But it also seems odd that the problem started relatively out of the blue. Of course it still runs like a champ!

Anyone else experience this? Does the leaking pre-chamber/injector that was mentioned have any merit? I'll pour water over the injectors, no problems there!

Would a bad lift pump do this? Not enough fuel to some cylinders?

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05 E320 CDI
99 SL500
02 530i

82 240D SOLD
83 240D Euro 4spd SOLD
86 300D Euro Auto SOLD

I changed my injector nozzles and it went away completely.

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1981 300D 205,000 mi.