W210 E240 Auto gear change problems

[nixopolis]

Greetings to all - this is the first time I have posted here and I hope you can help.

My 1999 E240 (79000 Miles) has a problem when starting from cold. After about 5 mins driving, sitting at about 40 mph / 2000 revs (but before full operating temp is reached), I have noticed that the revs needle rises and falls noticable around the 2000 revs mark. The car seems to be hunting for a gear as the engine jerks/snatches. There is also a very short-lived low groaning noise from under the car. However, once the normal operating temp is reached, the problem goes.

Also, the Aircon / CC fan speed is disappointing at the supposed max - is it expensive/complicated to replace the fan blower/motor ?

Grateful for any advice you can offer.

 

[jberks]

Hi,
Not sure about the gearbox. It does have a different change point when cold so there may be a fault around this, perhaps temp sensor etc but I don't know it well enough. 2000rpm at 40 indicates you are in 4th - perhaps its thinking about dropping into 5th?
I would recommend getting the gearbox oil changed. MB do not have this on the schedule and some people have suffered failures as a result. It may help but is a good precaution in any case. (I'm having mine done shortly at 62k).

The blower I do know about. Firstly check the pollen filter - if this is blocked then you'll get poor flow. The filter is located in the passenger footwell behind the under dash panel. Slide back 2 plastic clips and remove the rectangular cover - just pull out the filter. If its the original one its probably due for replacement anyway.
If the fan is slow, does it whistle too? Every case I have heard about (including mine) has been down to the regulator. The fans themselves generally last forever. The regulator is about £125 and a quick and easy (10 min) replacement job. Just look up fan regulator on the forum and you'll find more info.

 

[nixopolis]

Re:

Thanks for the info - I am reconciled, I suppose, to changing the transmission oil, god knows how much that will cost.

Mechanic at local indy said the pollen filter was fine, needed a new blower motor. Merc dealer quoted (before VAT) either £275 or £593 (help me Baby Jesus) depending on the month of manufacture (apparently the motor design changed part the way through 1999, the newer one is actually the cheaper!). Dronsfeld quoted £164 inc VAT and delivery for a used one, which seems eminently more reasonable.

...off to hide under some coats until the weekend arrives.