We bought my wife a 3 year old SLK-230 two months ago - she thinks it is wonderful! And it certainly out-performs my Lexus RX300 (but there is less storage room in it!)

Anyway - does anyone have any experience or ideas of this problem:
Occasionally when she tries to pull away, even with the accelerator pressed hard to the floor, the car takes seconds to accelerate ... really sluggish performance. She ends up stranded in the middle of a junction (very worrying).
There are no engine fault lights (and the wheel slip light does not come on) - our local service dept says there is nothing indicated by the engine management unit.

Of course - when we take it for service, it does not do it. And we cannot find any pattern that causes it so far.

Any suggestions would be very much appreciated

Thanks ...

 

Source of your problem could be bad (low grade) gas or water in the tank.

Also make sure you pump the correct grade of gas as specified in your owners manual.

Hope you resolve your problem soon. Good luck.

 

Thanks Benggolf ...
We always put top grade in it.
The service tech said that the check engine light would come on if it was a gas/water problem - do you disagree?

Ian C. Gloucester, MA

 

I have heard of this a couple times and the problem was some electronic part inside of the transmission that had a broken contact, so the transmission wasn't shifting right.

 

My 99 SLK230 developed the same symptoms that you described.
It took MB about five visits before they tracked the problem down and fixed it. The SLK has a fly by wire accelerator system. Basically there is no direct connection between the accelerator cable and the engine. The cable feeds a computer which does realtime engine management diagnostics before telling the engine what to do. The sluggishness you're experiencing is the computer not getting the right signals (air, fuel....) to meet the demands that are required to accelerate the car. MB initially changed the plugs, altered the timing characteristics of the engine, replaced the supercharger air feed check valve without any luck. In the end it turned out to be a ruptured air regulating diaphragm. To make think worse, some of the diaphragm material had embeded itself on a down stream air sensor. Basically the complete engine air regulating control loop was effected.
When the problem was fixed, not only did the car accelerate better, idling and fuel consumption improved as well.
Hope this helps.

 

Thanks everyone for your replies ... especially rghinzel; your description sounds a lot like the problems we had.

Took the car in last week and the dealer reported finding a code which implicated the accelerator, so they replaced it. Now we have to wait and see if the fault is gone. Easy to know if it has not gone ... hard to know if it is fixed.
And the warranty runs out in less than six months.

Anyway, thanks again.
Hoping for the best.

Ian C. Gloucester, MA

 

I had a similar problem, when I would take off it would sometimes almost bog down.

I had taken it in for service before for a passenger window that would not go up correctly, and the Check engine light was on sometimes.

They fixed the window and said that the fluids were alright and that light was now off.

I brought it home and it lasted about three days before the light came back on. SOOOO about 6 months later I took it back in due to the fan making a shreeking noise. I figured since it was in I would again ask about the light.

This time they said that it was a sensor for the CAM. They replaced it and now it goes like a scalded cat! all the time.

Mike