Stuck in winter mode? Extremely poor response from stop

[tesdaburys]

Mercedes SLK230 Kompressor automatic R170 2000 (Spanish LHD, they don't rust in Spain at all )

95% of trips are fine. The performance of this car is fantastic with very satisfying acceleration but sometimes I get this...

Pull up at a junction, pull foot off brake, car rolls as expected, apply throttle, feels like nothing is happening other than the slightest raise in RPM and speed for what feels like 2 seconds, I'll put my foot to the FLOOR then the revs will gradually build and finally will get some good acceleration but nothing like when the car is behaving normally.

Putting the gearbox in manual still causes the same issue when in 1 and pulling off.

It feels a lot like the car is stuck in winter mode or something. I saw a post somewhere saying that they saw a car with the wrong rolling radius tyres causing it but I'm not convinced this is the same problem.

Sometimes stopping and restarting has solved it but not this morning. I'll have to wait to drive home to see.

Related to the MAS? Do I consider replacing it? MAF sensor? Should I replace that? Dodgy W/S switch?

I've seen someone post on another forum very similar symptoms with the same car but this was 7 years ago and there was no response.

THANK YOU - Chris

 

[Howard]

Get the codes read before swapping anything

 

[neilrr]

When was the tranny fluid last changed?

http://www.mbclub.co.uk/forums/engine/124857-98-c250-dt-tranny-acting-up.html

 

[tesdaburys]

Thank you. It's done about 90,000 and I now suspect it's not been done.

 

[neilrr]

Dunno if that'll fix it but it's where I'd start.

 

[Rory]

Sounds similar to going into limp mode - are the revs limited?

Did cars of that age have such a feature?

 

[malphadour]

If you can only get to about half the red line (2500 in diesel and about 3500 in petrol) then it is in limp mode. If it is intermittent then get it on a star diagnostic at a local indy. I had similar intermittent problem and it was the MAF sensor - they seem to be a common problem.

 

[tesdaburys]

Sounds similar to going into limp mode - are the revs limited?

Did cars of that age have such a feature?

I am aware of limp mode but I will check it next time it happens. I didn't get a sense revs were limited (as it would seem to accelerate well eventually). Just that the response from gear 1 was extremely sedate for about 2 seconds and only then did it begin to behave as normal.

I read somewhere there are different kinds of limp mode. One where it will pick the last known good gear but everything else is the same but that didn't seem to be what it was.

Thanks all for the direction.

 

[Rory]

I read somewhere there are different kinds of limp mode. One where it will pick the last known good gear but everything else is the same but that didn't seem to be what it was.

This may be different on your car but on mine there's an emergency mode where it will stay in one gear. In limp mode the gearbox works OK, but the revs are limited to about 3000 and the turbo and kickdown don't work, so the car goes, but feels very sluggish.

 

[Auto-mobile]

Personally id spend the money from a tranny service on diagnostics.

 

[didi w203]

Could it not be the torque converter? Had same problems on b m w's. Once changed...perfect..or fluid could be contaminated? I have a mate who is a gearbox specialist and he checked out old tc and it was fine but had water in the converter. I could be wrong?

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