ML270 Auto not engaging neutral

[rbanwell]

Hi.

I have a 2005 ML270 and have a problem with the automatic gearbox.

When I apply the brakes in order to stop completely, it does not engage itself into neutral. So although I'm stationary with the brake on, the car is still trying to pull forward.

My temporary solution is to slip it into neutral using the gear shift as I approach a junction and back into drive in order to pull away.

My local independant has cleared down all the histroical error codes and none have reappeared although the problem persisits.

It has had the problem for a few weeks now but doesn't appear to be getting any worse.

Any ideas?


Thanks.

 

[Oarsman]

I've never known an automatic gearbox to engage neutral when the vehicle is stationary. The box is constantly engaged, unless in neutral or park.
If the car is pulling forward too much, then maybe the idling speed is too great.

 

[rbanwell]

I've never known an automatic gearbox to engage neutral when the vehicle is stationary. The box is constantly engaged, unless in neutral or park.
If the car is pulling forward too much, then maybe the idling speed is too great.

Graham - thanks for your reply.
Sorry, I'm not too technical. The probelm that I have is that the car is trying to pull away whilst I'm sat at a junction with my foot on the brake. It's straining forwards whereas previously it was like it was in neutral (may not have actually been in neutral).
Richard.

 

[Paul1234]

Sorry to bring up an old thread people but was this problem ever solved? I have just bought one of these and have exactly the same problem, when I engage drive the revs increase too high and it tries to drive off on it's own, I have had it diagnosed and no faults were found, it is there from the moment I start the engine but does get slightly worse when warm, any help would be greatly appreciated, Thanks.

 

[grahamcol]

I don't fully understand the problems here. On all automatics I've ever driven there is always some degree of "creep" which will not stop unless the selector is moved from D to N or P. Maybe the later cars select neutral when the vehicle comes to a complete stop, but I've not driven automatics later than year 2000 so wouldn't know. If the later cars don't select neutral by themselves then I guess there will always be a certain amount of creep. This will, of course, be made worse if the engine idling speed is too high.

 

[star]

If your idle speed is correct then there could be a problem in the gearbox or torque convertor dragging.

 

[Paul1234]

I probably picked the wrong thread, although it doesn't select neutral and there is some creep what I am experiencing is quite harsh, it will jump when drive is selected and try to take off on it's own, it will accelerate to about 20mph and if you hold your foot on the brake at traffic lights with it in drive then it vibrates and jumps around trying to drive off. Thanks for the quick replies.

 

[Paul1234]

I forgot to mention that it idles fine when in neutral.

 

[star]

Then as my post, you can try and take out the torque convertor via a star machine as a test.

 

[Paul1234]

Thanks for the replies, Seems I have to take it to a specialist then, if it is the torque converter what are my options regarding fixing it? Sounds expensive!

 

[television]

I would get the car on STAR to see what is logged

 

[tode]

Just for info, What is the correct idle rpm on these engines ?

 

[Mcercedes]

Hi PAUL123,

I have same problem with ML270 (2003) automatic, did you find any solution for that?

 

[ant225]

Hi there, did anyone find the soloution to this problem? I've spent loads of time and money on this one already, changed the Maf, an injector, no fault codes, cleaned the Maf, and the car still wants to pull forward alot when the car is in drive and I have my foot brake on. the engine speed dips and I get black smoke as the engine is under lots of load, really hope someone here can help

 

[richard neaves]

does anyone know of a solution for this i have same prob thanks

 

[Miffy]

I would get the car on STAR to see what is logged

for everyone asking the same question, please note the above

 

[Steve@Avantgarde]

Yes it did get resolved. I fitted a second hand gearbox and recon TC to it.

The OPs car had one of the strangest faults. You could not hold the car on the brake pedal, it would do 20mph without touching the throttle and would slam itself into reverse.

We changed the gearbox oil and filter and no improvement and no real clues on the adaption data either.

I spoke to my friend who works at another Indie in Bristol who said he had seen it before on a CLK and he went down the route of fitting a TC with no improvement then a replacement box.

I spoke to the customer and agreed the best way forward would be to fit a replacement box as if I fit a TC and it doesnt cure it then he would have to pay the labour etc twice which would be half the cost again of a replacement box.

After I replaced the gearbox and reconned TC all was fine.

 

[oigle]

Yes it did get resolved. I fitted a second hand gearbox and recon TC to it.

The OPs car had one of the strangest faults. You could not hold the car on the brake pedal, it would do 20mph without touching the throttle and would slam itself into reverse.

We changed the gearbox oil and filter and no improvement and no real clues on the adaption data either.

I spoke to my friend who works at another Indie in Bristol who said he had seen it before on a CLK and he went down the route of fitting a TC with no improvement then a replacement box.

I spoke to the customer and agreed the best way forward would be to fit a replacement box as if I fit a TC and it doesnt cure it then he would have to pay the labour etc twice which would be half the cost again of a replacement box.

After I replaced the gearbox and reconned TC all was fine.

Interesting, Steve. Did you make any effort to find out what the actual problem was? Might be useful for future issues.

 

[mya160]

Did anyone look at the air conditioning relay?

Usually when the A/C is selected, the idle revs increase to compensate for the drag of the A/C compressor.

It maybe that the revs are being increase too much.

This would not show up as a fault, because it would register as working correctly if the relay increases the revs.

Just another idea.

KenM