CLK320 Automatic Transmission

[Mini]

Hi, I am new to the forum (2001 w208 CLK320 Coupe). Have seen a few posts relating to transmission issues, but most of them mention 'limp mode', but I don't think the problem I have really causes the 'limp mode' to activate.....yet!

The car has become very sluggish over the past 4-5 months , and initial thoughts were MAF, so replaced this; but no effect. When I realised that the MAF had no effect, I started looking more closely at how the car was revving etc, and noticed that it consistently 'over-revs' slightly before you get the actual acceleration from the car and the problem is getting progressively worse to the point where I have to kick-down a lot of the time just to get some decent power out of the car, which is obviously having a negative effect on the fuel economy. Also the timing of the gear shifts also seems a bit erratic at times.

During a recent 'B' service at a local specialist, I had them do a FULL diagnostic, but no fault codes came up. The mechanic after driving it said he suspected a dodgy 'electronic plate / conductor plate' (whatever the right terminology is!).

Could the leak, which went un-noticed for a couple of weeks, have had an effect on the conductor plate in any way? and has anyone been through this before?

Plus, does anyone know any decent independents around the Bracknell/Sandhurst Area? I had the 'B' service done at Mercs Only in Hanworth cos its close to work.

 

[fnkhan68]

I think you should get a 2nd opinion, I wouldnt personally class Mercs Only as specialists. I can recommend AMC and Merc Services, both are in London SW17 but im sure someone else would be able to recommend a specialist closer to you.

 

[Mini]

Thanks for the response; I am looking to maybe get it into the Ascot dealership, for them to confirm one way or another.

 

[Dieselman]

You mention a leak, presumably ATF. That would account for the sluggish behavior and flared shifts.

Has the fluid been changed or just topped up?

 

[Mini]

ATF was leaking (slow) and the chap fixed this, and while he was at it I asked him to do a gearbox service (fluid and filter change); so the ATF was replaced completely........and since then, I have noticed no further ATF leaks. Speaking to one of the engineers at Ascot MB some time ago, he did mention that mercs are very sensitive to the ATF level being spot on, litlle too less or too much, can cause problems. Is this true? or was he trying to lure me into the stealerships grasp?!

 

[BlackC55]

That is true.

 

[Mini]

Ok. I think its gonna be a fluid check/second opinion from Ascot dealership........then down the conductor plate route if fluid check ok?

The conductor plate just seems to be a recurring theme in alot of these forums when it comes to similar gearbox issues.........

 

[BTB 500]

Conductor plate problem does tend to put the gearbox into limp home mode (locked into 3rd) though. That's certainly what happened with mine, it only happened occasionally and it was OK again after turning off and on again. That doesn't sound like your problem?

Edit: I also had fault codes stored.

 

[BlackC55]

If a speed sensor has gone down it normally loggs a fault code. (speed sensor is on the elec plate)

 

[Mini]

Conductor plate problem does tend to put the gearbox into limp home mode (locked into 3rd) though. That's certainly what happened with mine, it only happened occasionally and it was OK again after turning off and on again. That doesn't sound like your problem?

Edit: I also had fault codes stored.

Bill, As far as I can tell, the car does not go into 'limp mode', I can drive on the motorway quite normally and the revs dont suggest that it is stuck in 3rd gear. And now I mention motorway driving, the problem becomes less apparent at motorway speeds (probably because sticking in one gear rather than shifting around). I reckon its ATF level, maybe too low at first when I had the leak, now possibly too high if the chap just filled it right up. Hopefully get round to checking this out over the weekend at the dealers............unless someone could tell me where I can get hold of a 'special' dipstick from and do it myself?

 

[BTB 500]

Limp mode is pretty obvious - you have no reverse gear, for a start! Also once engaged it doesn't 'go away' without you turning off and on again. So doesn't sound like that's your problem.

Think you can order the dipstick from a dealer, probably cheaper just to get them to check the level though.

 

[Mini]

Had ATF level checked at dealership; all is good according to them, but they did notice something up with the shifting. Booked in for an 'investigation' tomorrow.............will update.

 

[Mini]

Had checked on Saturday. They reckon all is good, but reset the adaptive transmission via the computer. seems to be a lot better now..........but im sure ive done the reset trick before too..............

 

[Glenn Smith]

I changed the atf and filter in my c230k, had the battery disconnected at the time, gear changes afterwards were noticably worse especially 1-2nd when cold and down changes were more noticable with a bit of a clunk after stopping, it took a very long time to re-adapt, and now is as good as it was, 1-2 gives a slight jerk when cold due to the extra revs during warm up, but it always did, this is easily cured by using in W mode, but the box does tend to change up earlier and requires more use of kickdown as you would expect.