I have a loud noise that has been in coming from the motor for years.

It is not a knock, it just sounds like someone turned the volume up on the diesel engine.

I was told (but don't know if it is true) that early model 300D's had cylinder heads that caused this along with motor mounts that contributed to it.

Is it true that later model 300D's had a different cylinder head and liquid filled motor mounts to dampen the noise?

Any help is appreciated,

Dave

I believe the motor mounts are just rubber on later models, but not sure.
Do you have a hood pad?
Is there insulation in the foot well?

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83 SD

84 CD

Replacing all the mounts and the engine shocks helps a lot. An intact hood pad is also a good thing.

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Post a clip (and dont make a mistake that I did and take it in the garage , that distorts the sound). Do it outside and let us hear it

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'82 300D (project)
'46 Willys (project)
"Nothing seems to be the way it should in this garage." -jt20
"Smarter than an engine, dumber than a hoodlatch..." -jt20
"Start jumping up and down to smoosh down those engine mounts" -DeliveryValve
"no" -kerry
"At this rate, you may have it done by winter" -layback40

It sounds like a Sherman coming from 100 yards away. The noise is as much external as it is internal. It just sounds LOUD.....

My 220D is quieter.

????

Exhaust leak??

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'82 300D (project)
'46 Willys (project)
"Nothing seems to be the way it should in this garage." -jt20
"Smarter than an engine, dumber than a hoodlatch..." -jt20
"Start jumping up and down to smoosh down those engine mounts" -DeliveryValve
"no" -kerry
"At this rate, you may have it done by winter" -layback40

WHen was your last valve adjustment? I'd put my money on non-adjusted valves and injectors in need of rebuild.

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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

It isn't exhaust, that much we can tell.

I'll start with valves, then injectors and then motor/transmission mounts.

Does this seem like the logical order?

maybe the vacuum pump. i have a loud knock coming from the front of mine as well and it seems to be from the VP. if you put your hand on it you can feel it resonating

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83 300SD 226k virgin.

05 chevy duramax :bowdown:
air suspension + 500hp = fun for everyone

01 silverado 2wd 1500 5.9 cummins

My 240D was always a lot louder than my 300, except at idle. Later, I noticed I had an exhaust leak at the junction of the exhaust manifold and the pipe. While messing around trying to fix that, I realized I had a crack in the exhaust manifold between the #3 and #4 cylinders. It didn't really sound like an exhaust sound until it got bad. I replaced the manifold with a junkyard unit and all of a sudden the 240D was quiet, or at least quieter than it ever was before.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

Thanks for all of the advice, atleast I have a starting point and path to follow,

PS-I agree with Skippy on the bacon. (Especially Wrights Pepper Bacon!)

Some ideas for the list:
Verify that your air cleaner hold downs are not degraded leaving it flopping/rattling.
Verify that your pullys are not loose and that belts are tight. (do NOT turn pully bolt ccw!)
Do a diesel purge and an italian tuneup.
Clean the banjo bolt on the back of the intake manifold.
Check for air leaks in the fuel system. (I'm working on this problem with mine.)

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Codifex
1981 240D ChinaBlue (Got her running with a donor engine.)
1983 300DTurbo w/sunroof.
1984 300TD manual sunroof. (Electrical Gremlins)