Please help! SLK with lack of power

[apollo]

Hi there,
Please could anyone help me with a problem i have at the moment with a 97P slk 230 kompressor auto?
I just picked the car up and to be honest I thought the car was running fine.
Ticking over nicely, pulling away fine also driving sensibly.
But then I had to pull out into a gap of traffic so pushed the pedal to the floor when I discovered there was no power in it at all.It just seems as though its holding back and spluttering.
I took it to my friends garage and he put a diagnostic on it and it showed that no.1 and no.4 plugs had malfunctioned at some period.
As it has 2 coils, one running 1 and 4 and the other running 2 and 3, I jumped to the conclusion that it may be one of the coils breaking down under load, so i bought a new one.This didnt make any difference.
Could anyone please give me any ideas?
To recap, this car drives really well, and idles well, but put your foot down hard and its not going any where.
Im edging towards the throttle body and the ecu but really not sure what to buy.
Has anyone unfortunately had the same problem to give me a little advice?
many thanks
ken

 

[television]

Possibly the MAF filter that needs cleaning or replacement.

malcolm

 

[apollo]

slk lack of power

Thanks for that but i dont think its got one.
its got the siemans vdo throttle body on it and im pretty certain thats all thats there.I cant see a separate air mass meter.
cheers
ken

 

[apollo]

heres a photo of whats on there.
cheers
ken

 

[ProfessorX]

Sounds exactly like the problem I had on my W202 230K (98) and after cleaning the MAF sensor in mine as per the excellent advice of people on this forum it is driving as expected. I still have some other things that need to be tinkered with but the cleaning of the MAF and associated pipework worked like a charm

 

[The Rock]

Apollo, I've just had a quick cruise around the postings on this forum and there are definately people on here who say they have 97 SLK's with MAFs.

I'd certainly start with cleaning it, carefully, as described in other posts.

Rock.

 

[apollo]

Thanks everyone, I ll have a look.
Only thing is when I tried to buy a new one they kept giving me a Bosch unit which you just insert in the plastic housing with 2 screws but mine is not like that.
thanks again
ken

 

[The Rock]

Jeepers, man, don't buy a new one. They're massively expensive and cleaning the old one will give a good indication as to whether that's the problem. And, I cleaned mine months ago and it still works beautifully.
Rock

 

[apollo]

They re not too bad in price thankfully.
Just looked again and mine hasnt got a separate air mass meter, it must be built into the throttle body which ive just cleaned but to no avail.
I really dont mind buying a complete throttle body if i know for sure thats what it is? But im also being told that the ecu plays up so im really not sure.
cheers
ken

 

[television]

They re not too bad in price thankfully.
Just looked again and mine hasnt got a separate air mass meter, it must be built into the throttle body which ive just cleaned but to no avail.
I really dont mind buying a complete throttle body if i know for sure thats what it is? But im also being told that the ecu plays up so im really not sure.
cheers
ken

Ken,put up the first 6 vin numbers WDB------

And I can tell you.

Malcolm

 

[Uncle Benz]

You are looking on the wrong side. The MAF is towards the nearside of the car half way down beside the radiator.

 

[apollo]

Thankyou so much.
Its WDB 170447 2F022501.
Cheers ken

 

[apollo]

OOPS!
Thanks for that, I ll have a look in the morning.
People are very helpful here.
Much appreciated.
ken

 

[Ultymate]

Why is the same question on two threads

 

[Ultymate]

The photo you've posted above is not the throttle valve, It's the bypass valve that dumps the Supercharger pressure back into the aircleaner at idle.Your MAF is in the inlet duct on the opposite side of the engine down behind and towards the bottom of your radiator

 

[jimsinessex]

Just to add a little more info on the valve in the pic.

MB refer to the valve as a "recirculating air flap" on their parts diagrams and it modulates to act as a waste gate (in turbo terms) to control the kompressor outlet pressure.

At idle the kompressor is declutched on the older model (newer models do not have a clutch) and this valve opens to provide a direct path from the air filter to the engine as no air would pass through the kompressor.

Jim

 

[apollo]

WoW!!!!
I really would like to thank everyone for their time and effort on this.
I took the car to my local garage a couple of weeks ago and they told me it didnt have a maf sensor and pointed towards the throttle body itself on the left.They said it must BE BUILT IN TO THAT SO UNFORTUNATELY IVE BEEN ASKING EVERYONE FOR THE WRONG THING.
On your advice, i looked this morning and there it was. I took it off and cleaned it ,put it back but still run rough.
Went and bought a new one, fitted it and hey presto its fantastic!
Problem solved.
THANKS AGAIN EVERYONE FOR YOUR HELP.
cheers
ken

 

[Glenn Smith]

WoW!!!!
I really would like to thank everyone for their time and effort on this.
I took the car to my local garage a couple of weeks ago and they told me it didnt have a maf sensor and pointed towards the throttle body itself on the left.They said it must BE BUILT IN TO THAT SO UNFORTUNATELY IVE BEEN ASKING EVERYONE FOR THE WRONG THING.
On your advice, i looked this morning and there it was. I took it off and cleaned it ,put it back but still run rough.
Went and bought a new one, fitted it and hey presto its fantastic!
Problem solved.
THANKS AGAIN EVERYONE FOR YOUR HELP.
cheers
ken

Excellent result, may be worth cleaning the engine breather sytem to keep the new maf in tip top condition, it's usually oil that messes them up. And that reminds me i must clean mine as it felt a little slower than usual, or may be i got used to it?

 

[The Rock]

WoW!!!!
I really would like to thank everyone for their time and effort on this.
<SNIP>
Went and bought a new one, fitted it and hey presto its fantastic!
Problem solved.
THANKS AGAIN EVERYONE FOR YOUR HELP.
cheers
ken

Well done, Ken. Like the advice from Glenn says, I'd make sure that the pipework around the MAF and the filter in the pipe in front of it is all nice and clean too.
So glad your slk is back to normal.
Rock.