Hi all, I've recently bought a 1998 SLK230k, (auto)and it seems to be down on power. With the foot to the floor it is very sluggish. It seems to have developed a bit of a shudder when driving. I'm also in two minds as to whether the gear change is working properly too as it seems to take a while to change up. I canhear a kind of sucking noise when I accelerate too, never heard it before now. No warning lights have come on. All help will be very grateful! Cheers!

 

It could be the Supercharger is going. I have herd of that a couple of times going on those cars. Also it could just need a good tune up.

 

Start with basics, change fuel filter, air filter.. The noise your hearing might not be a sucking but a blowing noise, check all lines, connections for supercharger,intercooler,intake tubes, all boots and clamps...

 

Well comming from a work of turbos if it bucking or shutter could be leak after the supercharger, also check fuel related componants and connections.

 

I had to change the Mass Air Flow Sensor on mine. Sounds like very similar symptoms. Cost me $500 from the dealer. I went through plugs and wires first and that didn't work so i went to the sensor and that solved my problem.

 

Thyere are several threads about MAFs. I havve replaced mine x2 on my 99 SLK 230 but some of the threads suggest a good can of MAF cleaner is the place to start. As I remember, it is important to keep the electronic components free of the cleaner stuff. Look up MAFs in the forum and it should give you a lot of info.