Julian2

My car won't rev above 3krpm and won't change down on kickdown .After driving a few miles this fault goes away but returns after a short time . The car is prone to stall when maneuvering in a tight place at very low revs and seems to be connected with use of the steering at full lock .There is also hesitancy and jerkiness when driving in traffic and very low revs .
No warnings are showing on the instruments . So far I have cleaned the Maf sensor although this was not a "thin wire " type but the Pierburg type with no difference . Disabling of the MAF sensor makes no difference to the car's performance ..I have also checked the level of the transmission fluid which is OK .
Any help welcomed with thanks .

Carsy

Just wondered how many Kms the car has done & whether you could scan for fault codes. To me it sounds more like an engine problem rather than transmission.



Take a look at these posts to see whether you can diagnose the problem:-

By ausmbtek :-Does it always have low power or is it fine then looses power after driving for a while?

Common issues are jammed turbo vanes, air flow sensors, EGR valve blocked, boost pressure sensor faults or vacuum leak to the turbo control valve or damaged intake manifold flaps.

Only having the fault code for low boost pressure and if there is never full power then I'd suspect the boost pressure sensor, vacuum leak or turbo vanes jammed.

Good power than loosing after extending driving (usually constant speeds) mostly jamming turbo vanes.

Cats usually give low power all the time, sometimes after changing the cats the air mass meter dies (it would already be failing, but the sudden increase in air flow takes it beyond it's useful range and trips a new code).


Cats on CDI2 engines (mostly ML270) regularly blocked up in Australia, CDI3 engines rarely block cats unless the driver is particularly gentle. This is due to fuel being more finely atomised/less soot on the CDI3 and later engines.


https://mbworld.org/forums/c-class-w...convinced.html


https://mbworld.org/forums/c-class-w...uch-power.html

Please Llet us know of the outcome,

John C.

Carsy

Thanks Carsy !!!!!!!!!!!!!!!!!!!!!!!!!!!

Julian2

Yes thanks indeed Carsy and apologies for not posting sooner .As I type the car is in the local garage to see if something can be diagnosed .It also needs a bottom ball joint in the front .It has covered 100k miles and is a 2001 model . Easily the most troublesome car I've had from suspension joints , bushes etc to electronic woes . Yet it's a very nice car to drive when it's running Ok which is why I've hung on to it .
I'll come back when I've got a diagnosis .Again apologies for my oversight . I know how it feels when information is not acknowledged .

Carsy

Julian,

Good luck with it all. Hope you can sort it out.

John C.

Julian2

Thanks John .
Diagnosis apparently showed a MAF sensor fault .Hmmm. not so sure , but they'll fit a new sensor today and we'll see.

Carsy

Great news, if to can get away with that you have done extremely well .

Thanks for the update.

JC

Julian2

Well John I picked up the car yesterday afternoon and since then it's done 50+ miles with no problems .Good outcome for me and cheap at £65 ,just replaced the MAF sensor .

Carsy

Well done . I will keep it in mind with mine. Interesting that you had no codes to point to the problem. Obviously you have a good mechanic.

John C.