revs increase when stopped in gear,auto

[daz7]

Hi i hope someone can help

I have an E320cdi estate automatic. when she's in a stoped position in D and R with the foot brake pressed the revs incrsase and from D to N and R to N it clunks, it has been going on for a few months and nobody seems to know whats
causing it. Is it doing any damage.

 

[Stevie A]

Find a friendly delear who is not going to rip you off and get them to tell you what is wrong. One hour labour max. Anymore then they are overcharging. Get them to tell price upfront then you can't get bumped. If gearbox faulty you can get them from a scrapyard or something cheap but if you can afford a modern Merc you should be able to pay for a new gearbox.

 

[television]

Two things here, One is that the Idle speed could be out of adjustment, normally its the other way around, the revs are normally increased when you put the car into D or R.
If the revs are normal then the clunk could be the prop shaft spiders worn or the pinion bearing in the diff worn.

Malcolm

 

[television]

I am changing my answer here, Almost every car I have had has been an auto, with these cars the Idle speed has been 500/600 RPM, putting them into D or R the speed is increased to 800 RPM.
Out today with my MB, idle speed 600 RPM put it into D and RPM go down to 500.
The clonk part stays as above unless the Idle speed is too high
Perhaps someone with a 320d Auto could tell us what there's does

Malcolm

just found something else, if it gives a double clunk MB say change oil in gear box, Drain 5 liters and refil 5 litres of ATF fluid..DO NOT USE ATF with part number 001 989 07 03/11