ML 270 G/Box problems

[Michael Greaves]

Hi I have a 2003 ML 270 it has 150K mls.
When the engine is cold (pre stat opening) the gearbox and kickdown work perfectly. Once engine is at running temp I lose K/down and when going up hill either towing a trailer or not the car labours and I have to use the stick to knock down a gear. I also find that the car will not go over 80 mph any help would be appriciated

 

[DSM10000]

It could be a number of things so getting codes or live data read on a Star computer would be the best way forward.

The problem could be caused by a faulty Mass Air Flow meter and not be a gearbox issue. When cold the ECU will use a different set of values, when warm the MAF may not be sending the correct signals, the gearbox ECU and engine ECU work together to generate the information for shift points etc.

It could also be a split or loose hose somewhere, have you checked the intercooler hoses and all other engine pipework?

 

[panason1c]

As above, could also be a problem with the inlet manifold flaps/flap motor.
Codes need to be read to confirm.