s320cdi rumbling noise from rear

[bernardfowler]

when the car is in top gear and you let the revs drop to say 1000 when you gentley accelerate there is a vibration from the rear of the car.we changed the gear box oil and cleaned the maff sensor car fine for two days then noise returned. had it plugged in diao showed no faults. any ideas please.

 

[jibcl500]

Torque convertor, what oil did you use?

jib

 

[bernardfowler]

we used mercedes gearbox oil but only managed to get 3 & half litres out

 

[television]

It could be worth having a glycol check,just in case there is a leak.The glycol contamination is described as a humming or droning when pulling in top gear at between 1200 to 2300 rpm

 

[television]

we used mercedes gearbox oil but only managed to get 3 & half litres out

The rest of the fluid was in the torque converter

 

[bernardfowler]

glycol?
/

 

[television]

This can happen if the rad leaks into the oil cooler

 

[jibcl500]

Glycol doesnt affect the W220, you need to remove all the all 8.5 litres from a guess and change the gearbox filter at the same time, 3.5 litres is the gearbox only the rest is in the torque verter.

jib

 

[bernardfowler]

is it worth changing the oil again if it is the torque convertor thats gone?

 

[television]

Glycol doesnt affect the W220, you need to remove all the all 8.5 litres from a guess and change the gearbox filter at the same time, 3.5 litres is the gearbox only the rest is in the torque verter.

jib

No I agree it is not a listed fault,,but we have had 220 cars with this fault

 

[jibcl500]

You need to remove all the oil and filter and see if that helps, it should fix it but all the fluids have to be drained.
jib

 

[bernardfowler]

can you remove the oil from the torque converter as we couldnt find a drain plug?

 

[television]

You spin the engine for a few seconds to drain the converter

 

[bernardfowler]

hi do you mean that if we start the engine it will empty the torque converter ? or do we need to disconnect the pipes to the radiator? cheers mark

 

[television]

Ideally you need to spin the engine with out it starting, and you can remove the engine ECU fuse to do that.

Just undoing a pipe and spinning the engine will empty it