Anyone changed the plugs themselves on a CLK 55?

[i_york]

I can detect a very slight misfire at idle... so slight, you have to concentrate to detect it. However, as the car has now done just under 55k miles, it's fair to assume the plugs could be the culprit.

I'd like to change them myself in order to save £100+ labour from the local specialist. However, having had a quick look under the bonnet and seen the extremely limited access, it's a job I wouldn't want to even think about tackling without some tips from someone that has already skinned a few knuckles doing it themselves!

What tools should I have to make the job easier? At the moment, I've got a good 3/8" socket set with short and long extension bars and swivel socket. Are there any 'special' tools that I can buy to make the job easier?

Does anything need to be removed in order to make access with a socket and wrench easier/possible? It looks like the windscreen washer reservoir could get in the way, for example.

Any advice much appreciated.

Cheers,
Ian.

 

[Birdman]

stats007 (2001 SL500 Silver Arrow) may have changed his last year.

http://mbclub.co.uk/forums/showthread.php?t=16682

 

[stats007]

Mine is a 5.0 M113 and being an SL probably has a bit more room so I didn't need any special tools. I removed the air filter housing (just pulls off) and also removed each coil pack before getting at the plugs (numbering the coil packs and noting the position of the A / B leads). A very slight misfire at idle is common on these engines when in P.

 

[i_york]

A very slight misfire at idle is common on these engines when in P.

Is that attributable to the plugs failing? Or is it just a 'characteristic' of the engine?

Cheers,
Ian.

 

[stats007]

It appears to be a characteristic - if excessive it's usually the jumper leads rather than the plugs. It disappears when in D though.

 

[C240Sport97]

I don't get any misfire on mine

 

[stats007]

It's very subtle - though you might be lucky - every SL500 I've been in does it.