The only thing I can think of that is that loud is bad motor mounts, but you say you changed them. Are you using the stock motor mounts from the new motor? I'd suspect a slight binding there or at the tranny mount with metal to metal contact.

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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.

Does it make that noise at higher speeds in the higher gears? That video is around 35mph....

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http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

Im using w124 engine mounts and gearbox mount, all new and no metal to metal contact anywhere and the engine fits like a glove, no bending anywhere.
I had the same noise with the standard engine.

As stated it's from 30-50mph and the noise never comes back over 50mph, i've driven 90mph and it's perfect to that speed.

I suspect that the cause is either an exhaust leak or some other exhaust problem, or a differential problem.

If you can, raise the car on a garage lift and reproduce the noise (start the engine, engage drive, and bring the speedometer speed up carefully to make the noise again). DANGER: do NOT exceed 100kph on the speedometer - you may over-speed a tire and cause it to come apart at high speed, which can produce deadly flying tire debris. While inspecting the car from underneath, the cause of the problem may become very obvious.

__________________
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

ok, methodology...

noise present with original engine... ignore new changes.

noise is torque sensitive... so think about what torque is doing at low speeds, it's trying to twist the car to the right. get a jack, and push the motor away from the left side, and inspect what is touching.

I bet you find that the turbo is hitting something on the right side of the vehicle. turbo would be there, and if you are right hand drive the steering box would be there...

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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 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

From what you describe, it sounds like something is vibrating at the fundamental frequency of the body shell. That will make it hard to locate, because the vibration source can be small, and need not be in contact with the shell.

One thing to check is driveline alignment. Mercedes shafts will only work without vibration if the transmission output and the diff are exactly in line. It's not sufficient for the crank flange to be in the same plane as the diff flange, it has to be directly opposed. Otherwise, the u-joint creates a wobble which can be felt as a vibration. Unlike a two u-joint system, you can't depend on the driveshaft to absorb any misalignment.

My other thought is that this is related to the turbo or exhaust. You might try blocking the wastegate open as a test, and see if that makes a difference.

@Maxbumpo: It's not an exhaust leak and the problem is torque related so i cant get the sound to appear while the car is lifted, trust me i tried.

@vstech: The engine is miles away from even beeing able to touch anything so it's not that, same with the gearbox.
It's a non turbo engine aswell.

@Mxfrank: Yes that is pretty much my issue.
Driveline alignment is perfect so it's not that.
And again it's not a turbo engine, it's a NA om602.

I get that nothing is touching, but if you set a jack to pushing the engine towards the right side of the vehicle, then re-examine the entire driveline, you may find something that is touching.

it could be as simple as the bracket that holds the exhaust downpipe to the flex connector is misaligned... I would start by taking the exhaust off of the vehicle, and see if the vibration remains.

__________________
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 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

I have driven it without exhaust aswell, no difference and i pushed the engine all over the place trust me nothing is touching it's miles away.
Just to say it one more time aswell, i had the same noise with the standard engine aswell.
There is so much room everywhere around the engine, transmission and exhaust that it's literary impossible for it to move enough to touch anywhere

Okay I have another theory. How is driveshaft length? It wasn't a tight fit was it? Reason I ask is off the driveshaft needed to be compressed a little bit to install, you wouldn't notice it at certain speeds/rpm's, but at others torque could cause the driveshaft to become slightly twisted and take a spiral shape. Much like when the rubber isolator goes bad on the driveshaft center bearing, it isn't noticeable at certain sites, but others it bangs around in the housing and causes vibration.

__________________
1982 300D Turbodiesel, daily driver. Mods so far: Fram 8038 paper filter, 4 brake light mod, Gen II w126 (front) rotors/calipers, boost turned up to 12lbs, non-egr manifolds, water/methanol injection, 4-speed manual
1980 300SD Turbodiesel, project car, nearly ready to hit the street

1974 240D, New paint

Right now i have a shortended 240d prop-shaft on it so the length is perfect, i started of with a standard 300d prop-shaft and had no issues with it twisting.
I measured the play with a dial indicator and got 0.2mm (0.0078inc) of play on the worst place.

Jeezus it sounds like you're trying to talk to submarines and whales, that is some serious VLF you got going on. And that is what my truck sounded like at or near highway speeds

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1993 MB 300D 245K died.

CV Joint or wheel out of balance.

Perhaps then you need a lift which has the load drums built in, so the rear wheels are forced to push against them. This places an artificial load on the drivetrain, and should allow you to reproduce the noise while have the advantage of looking at it and hearing it from underneath.

A small-diameter rubber hose can be used to isolate the source of the noise. The hose needs to be meter or more long. Hold one end into your best ear (gently!) and then move the other end around close to all the possible noise sources. When you have the free end of the hose close to and pointed at the source, you will know it!

__________________
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

Yes, could be cv joints. Acceleration squats the rear a bit and takes the balls out of their well worn grooves making a racket. I had some once that were fine until I loaded the car for a trip squishing them down from their comfort zone.

__________________
[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.