w203 c320 Q's

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Nordboy

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Sep 6, 2009
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12
Car
ML320cdi
I have had my c320 estate for a week or so now ( 02 with 84k on the clock). I am having some worries about the gearbox. I've done a search on the site but can't find anything similar to my problem.
When i am rolling up to a junction the car occasionally seems to stay in 4th gear, shuddering slightly when at very slow speed. then when i need to accelerate i have to virtually kick down to get the gears to change and move forward as i have no acceleration due to it still being in 4th. Any ideas? I'm guessing it's still in 4th as when i move the tiptronic across 4 is still on the dash even though i'm stationary or at very slow speed. Apart from that the gearbox seems to change gear as normal as reasonably smoothly.
 
Does the car misfire at all? This could be an MAF problem
 
Has the automatic transmission fluid been replaced?
 
Thanks guy's

Has the automatic transmission fluid been replaced?

It has a full service history, but not all merc so i'm guessing they may have been a little sparing with following the strict service guide ( i can't find when the fluid should be changed in the service guide though ). This may be my first visit to the garage to get it sorted and the start of me spending money. If i go to a specialist will any gearbox prob's show up on the computer diagnostics?

Does the car misfire at all? This could be an MAF problem

No, seems to run really smooth.

Apart from the niggly little things that I need to get sorted out over the coming months, i'm enjoying my first Merc. It's pretty good to drive and very comfortable and effortless when on the go.
 
ATF should have been changed around 40-50K.
Some owners dont know or bother to get this done as its not part of normal servicing (therefore not mentioned in the service book) and its not cheap.
Cost to drain and change the fluid by a good indie should be in the region of £250ish - more by MB.
I would bet that's the problem, but of course I cant be sure.
 
£250 to change the gearbox oil by an indi,is this about right,does it require the box coming out!
 
ATF should have been changed around 40-50K.
Some owners dont know or bother to get this done as its not part of normal servicing (therefore not mentioned in the service book) and its not cheap.

Not only that, my local MB dealer refused to do it for me as it is 'sealed for life'.
 
My service book (2006 car) says ATF should be changed every 40k.

As a general rule, any issue with auto box should be first dealt with by ATF (and filter, if applicable) change, and only if this does not help then you should look further.

And it is a reasonably straightforward DYI job, though a messy one at that...

Also, keep in mind that by draining the ATF you are not really replacing it, but more like refreshing it, because around half of it stays in the torque converter and the oil cooler. Their is a procedure to fully replace the ATF by 'bleeding', very similar to brake fluid replacement, i.e you feed fresh ATF from one oil cooler pipe and drain it from the other, but no one actually does that - the most you will get in a garage is a straight drain and refill which as said will replace around half of the stuff.
 
Earlier 722.6 transmissions were 'sealed for life' with no ATF replacement specified.

MB changed service requirements on later cars to include an ATF change at 40k miles.
 
ATF fluid change on my SL was £147 at a main dealer, 3 years ago.
 
If unsure as to whether it's been done, changing the ATF would be a good move.

It's not cheap though and if there was a bigger problem which changing the ATF doesn't fix then it may be wasted if it's drained as part of a repair. Therefore I'd get an opinion from an MB specialist and/or Auto-transmission specialist first.
 
I charge £165 including a filter, gasket and a full flush out. I bet for £147 they only replaced the 3 litres in the sump!

Going back to the OP. You need to get the fault codes read first.
 
Not only that, my local MB dealer refused to do it for me as it is 'sealed for life'.

What a load of cr*p. And you can print of this page and show it to them if you like.

MB SAID that the boxes are "sealed of life" but of course that's simply not true.

Find a good local indie who will tell you what we have all said.

Better still...................if you live anywhere deep south, along the south coast or within a reasonable drive of Horndean, take it to Ollies at PCS (see post no.14, above).
He is fantastic and a wizard on all MB cars. He will sort out the problem - and at a lower price than most - 101% recommended.
 
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The car arrived at a set of lights yesterday, i could feel the car juddering as it hadn't chnaged out of 4th gear. i put the lever into N but the car didn't disengage 4th gear for about 10-15 secs. Then a malfunction popped up saying battery malfunction and a battery pics came up on the dash ( this malfunction has now gone). Surely a partially discharged battery wouldn't cause this gearbox fault? Is the battery a bi-product of the gearbox fault?
Do all the vehicle's fault's, inc gearbox show up on one of the fault reader's you can buy off Ebay?
 
Cheap code readers just do the engine codes.

Take the given advice and get a gearbox guy to do a diagnostic check, cant cost much as hes probably going to get the work, maybe even check it for free if you give him the job.

Search on here for gearbox oil level checking, low oil means low pressure to shift the valves solenoids etc.

The fact you had the battery light come on could be relevant ie is the battery sound or on its way out? again any half decent garage can check this for you.

Google w203 battery changing/removal problems.



Lynall
 
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