I recently had a used motor installed in my 93 300D, the old one was slam wore out. the used motor I had installed worked great BUT I have a clack or knock coming from it at all RPMs. To give you an idea how loud, if I turn the AC on High or crank the radio you can't hear it nor at highway speeds. Acceleration is according to spec, oil pressure pegged at 3 when driving and 1.5 to 2 @ idle when warmed up. Temp is normal. Mileage is as advertised. Starts with a touch of the key. I installed new lifters, no change at all, did a LUBRO MOLY purge of the injectors and pump IAW the instructions, no change, ran on straight Extra Virgin Olive Oil since I had the lines out anyway. No change in the knock noise at all. As I've said I've run this on Dino D, Bio D and VO with no change in performance. I think this motor would run on cat "P" but this noise is bugging the hell outta me.

What else can make this noise? Vacuum pump?

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1993 MB 300D 245K died.

That would be the most obvious place to start looking for your noise, but I would rule that out soon if I were you!

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All Diesel Fleet
1985 R107 300SLD TURBODIESEL
2005 E320 CDI (daily)

LOTS of parts for sale!


EGR block kit
http://www.peachparts.com/shopforum/diesel-discussion/355250-sale-egr-delete-block-off-plate-kit.html

1985 CA emissions 617 owners- You Need This!
Sanden style A/C Compressor Mounting Kit for your 616/ 617 For Sale + Install Inst.

Sanden Instalation Guide (post 11):
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Get a few feet of small diameter hose, put one end up to / into your ear canal, move the other end around the engine until you isolate the source of the noise.

Check the o-rings on the oil filter center tube - there are two small o-rings at the bottom, if left too long they get hard as a rock. If they degrade too much, strange noises can result. I can't explain why, but one poster just about went crazy trying to figure out a weird noise and replacing those o-rings fixed the noise.

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Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

A belt damper with worn end bushings can make a knocking noise. Does prying the upper attachment away from the head quiet the knocking?

Sixto
MB-less

I'll check all of those, thanks

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1993 MB 300D 245K died.

Clacking? Any possibility the injectors are worn? Injectors are only good for so long.

Does the noise get louder if you come to a stop sign and then accelerate?

Use a long screwdriver and listen.

Sorry you can't catch a break with these engines.

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Only diesels in this driveway.
2005 E320 CDI 243k Black/Black
2008 Chevy 3500HD Duramax 340k
2004 Chevy 2500HD Duramax 220k

no change in volume, I'm going to change the injectors just because. I have a new set in my tool box and got practice in with the old motor.

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1993 MB 300D 245K died.

What weight oil are you using?

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

15w40

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1993 MB 300D 245K died.