Engine/Transmission Sounds
#1
04-24-2012, 10:07 AM
Engine/Transmission Sounds
1984 300 Diesel Turbo
Recently purchased, was shifting hard and local MB mechanic took 3 weeks to clamp the EGR after fiddling with the vacuum system. I was told there was a "small" leak from the seal on the transmission pump, and the engine mounts and trans mounts would need replacing.
Driving on the highway (60mph), accelerating, large bad metallic/ mechanical chaos began coming from the motor/trans. The engine became significantly louder at idle, almost like there is a crack in the ehaust manifold, but significantly quieter under mild/moderate power. The trans began making a sound like I am dragging chains under the car, but the sound lessens as speed increases, to the point that it disappears around 40mph. At this speed with a mild/moderate throttle, the car is humming along, better than ever. If I let off the throttle, the loud idle engine sound begins, and the trans begins making a sound like a coffee can filled with metal lids and bolts. If throttle is reapplied, both sounds resolve. Then the trans began slipping a bit, which it had not done before...
This was all occuring on my way to work on a single drive.
With all the dramatic sounds, I drove the car in a friend's driveway near work and left it for a few days. I drove the car a little again (5 miles), but with all the sounds and mild trans slippage, so I left it in the driveway overnight. When I started the car in the am, it started fine, albeit loud at idle, but when put in gear, there was no significant activity from the transmission. I got out to discover the car swimming in transmission fluid. This fluid was not under the car when I got in to start it.
Last ongoing issue: The car only starts intermittently with the key. Key turns easily, glow plug indicator lights and goes out as expected. The previous owner said that the NSS may be the issue, so I replaced it. It still frequently requires that I "jump" it at the terminals on the passenger side of the engine compartment. (The mechanic said the starter was failing, but since it starts reliably every time I "jump" the terminals, I disagree.) Any ideas where else there may be a disruption in the ignition?
I have all sorts of ideas about these issues that I will spare you from. I am currently in the process of removing the trans to check the pump and replace the seal as well as the engine and trans mounts.
Your thoughts and insight is greatly appreciated!
Recently purchased, was shifting hard and local MB mechanic took 3 weeks to clamp the EGR after fiddling with the vacuum system. I was told there was a "small" leak from the seal on the transmission pump, and the engine mounts and trans mounts would need replacing.
Driving on the highway (60mph), accelerating, large bad metallic/ mechanical chaos began coming from the motor/trans. The engine became significantly louder at idle, almost like there is a crack in the ehaust manifold, but significantly quieter under mild/moderate power. The trans began making a sound like I am dragging chains under the car, but the sound lessens as speed increases, to the point that it disappears around 40mph. At this speed with a mild/moderate throttle, the car is humming along, better than ever. If I let off the throttle, the loud idle engine sound begins, and the trans begins making a sound like a coffee can filled with metal lids and bolts. If throttle is reapplied, both sounds resolve. Then the trans began slipping a bit, which it had not done before...
This was all occuring on my way to work on a single drive.
With all the dramatic sounds, I drove the car in a friend's driveway near work and left it for a few days. I drove the car a little again (5 miles), but with all the sounds and mild trans slippage, so I left it in the driveway overnight. When I started the car in the am, it started fine, albeit loud at idle, but when put in gear, there was no significant activity from the transmission. I got out to discover the car swimming in transmission fluid. This fluid was not under the car when I got in to start it.
Last ongoing issue: The car only starts intermittently with the key. Key turns easily, glow plug indicator lights and goes out as expected. The previous owner said that the NSS may be the issue, so I replaced it. It still frequently requires that I "jump" it at the terminals on the passenger side of the engine compartment. (The mechanic said the starter was failing, but since it starts reliably every time I "jump" the terminals, I disagree.) Any ideas where else there may be a disruption in the ignition?
I have all sorts of ideas about these issues that I will spare you from. I am currently in the process of removing the trans to check the pump and replace the seal as well as the engine and trans mounts.
Your thoughts and insight is greatly appreciated!
Last edited by mbzfan7007; 04-24-2012 at 10:16 AM.
#2
04-24-2012, 10:51 PM
When Cars start making awful noises it is time to get them off the road as soon as possible or you just increase the damage.
Drop the Pan on the Transmission and see if there are pieces in the bottom.
Inspect your whole drive train.
It is rather too late for the below article but I will include it anyway.
TRANSMISSION VACUUM ADJUSTMENT
Mercedes-Benz Transmission, Steve Brotherton, ImportCar, February 2002
Drop the Pan on the Transmission and see if there are pieces in the bottom.
Inspect your whole drive train.
It is rather too late for the below article but I will include it anyway.
TRANSMISSION VACUUM ADJUSTMENT
Mercedes-Benz Transmission, Steve Brotherton, ImportCar, February 2002
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