clk 230k cylinder 2 misfire

[robjogs]

hey wondering if anyone can help my clk has just produced a misfire on cylinder 2 but when I turn the car off and on again its fine until I put my foot down and then tho and behold misfire again...

would this be a cause of a coil breaking down????

 

[DSM10000]

Could be a coil, HT lead, spark plug, injector............. Ideally you need to get a Star diagnosis.

You could try moving a coil pack around an see if the misfire moves, I assume it has one per cylinder?

 

[robjogs]

it has a coil on 4 and 2

 

[grober]

It's known as a "lost spark" system. Each coil fires 2 cylinders 1 + 4 and 2 + 3. Usually its one of the coils or the coil extender that goes down below the coil to the plug. If a coil goes bad it sometimes takes out the control transistor/s in the engine ECU.

 

[robjogs]

how is it resolved? ??

 

[grober]

As DSM 10000 says best thing is to get the car on an engine analyser. Swapping the coils+extender over may help but the low tension wiring under that cam cover can degrade with the heat so must be handled with great care. If the problem doesn't move to cylinder 4 then the problem is going to be the coil or extender or low tension wiring or ECU output transistor. The coil extenders aren't too expensive so it might be worth changing them first.

 

[robjogs]

do u know where I can get just the extender part?

 

[DSM10000]

do u know where I can get just the extender part?

A dealer or try ECP etc.

 

[robjogs]

ecp only sell the coils

 

[WG M-B]

I would swap the coils to see if the misfire moves first. It could (less likely but possible) be a fuel injector

 

[robjogs]

problem solved was the coil extender thanks guys £12.50 cheap fix