Lumpy idle and a little flat

[Ian Topping]

Hi,

Please help, my CLK55 w208 is sick. I changed the MAF and this improved performance greatly and removed the stalling at lights however the car intermittently runs very lumpy.......if that makes sense??

The car seems to exhibit this misfire when hot, but it is intermittent.

Any suggestions

Thanks
Ian

 

[Howard]

Plugs / leads / coil packs ?

 

[Ian Topping]

thanks Howard,

Should I take the leap and change all at a certain expense or start with the most likely culprit?

 

[Howard]

Errrr ....

I'm no mechanic , so wouldn't like to say .

Thats just what i would be looking at , can you get it on a STAR ?

 

[IanW]

Personally, if the lumpiness when hot is a new arrival, I'd start by checking for air leaks/plumbing not replaced properly.
If that fails, then I'd try reading any error codes.
Ian.

 

[C240Sport97]

have you taken it for a long and fast run recently?

maybe it just needs to clear its lungs

 

[trainer]

Any excuse for a long and fast run!

 

[Ian Topping]

I have taken it for several fast runs, something I will obviously deny should the long arm of the law be enquiring!
My mechanic has done tests but can't say categorically what the problem is, however he has not mentioned anything about air leaks, can you give me more detail on this and I will discuss it with him?
thanks

 

[barneypeter]

similar on my c180 was told to disconect battery to reset ecu but there is a procedure to follow,and clean or change breather pipes,and with the new maf,all is good

 

[IanW]

My mechanic has done tests but can't say categorically what the problem is, however he has not mentioned anything about air leaks, can you give me more detail on this and I will discuss it with him?
thanks

Nothing specific, but I noticed that failing to seat the plastic cover back over the MAF inlet caused my engine to run a little rough at hot idle. Presumably, hot air from the engine compartment is being taken in, rather than cool.
Ian.

 

[Ian Topping]

I am very pleased to report that I took my beloved CLK55 to a Merc specialist and he ran the STAR diagnostics and reset all the faults and since then the car has been running very well.
This was only yesterday, so I hope I am not tempting fate

 

[bongodopey]

Merc Specialist

Hi Ian - David McCoy here - can I ask which merc specialist you went to?

 

[strikemaster]

Fault codes would have been interesting.