cl600 bi turbo performance

[guv]

my car suffered intermittant misfires shortly after buying it, and as I have been driving its gradually got better over the last few months, if I add any fuel cleaner, within around 10 mins the car starts to idle badly and shake.

its now running on esso fuel, and all seem well, apart from when I put my foot down, car pulls strong then around 4-5k gets another kick of power, I am getting no faults on the dash, and MB say its the coil packs, but I cant see both failing at the same time, and £1k as side seems alot for a guesstimate, the car was serviced prior to me getting it it, and I am wondering if incorrect spark plugs would have this effect, the car is pulling 500bhp on a rolling road, and the only think we noticed was a damaged pressure sensor coming from the l/hand charge cooler, I have since replaced this, while this pipe was off the turbos spooled but gave no power,

in the usa, there is a company that rebuilds these coil packs, for around £235 per side with lifetime warranty, I am sure there must be a UK company that can do this? as I said I dont mind changing the packs to see if it cures but not for a grand a side,

I have had the secondary water pump changed / system bleed due to high charge temps, as I was told this was causing the performance problem, now its the coil packs...

 

[television]

Not easy to check the sparks on that set up.

As it runs fine at times,could it be the MAF sensor going down

 

[guv]

Not easy to check the sparks on that set up.

As it runs fine at times,could it be the MAF sensor going down

I thought about the mafs, but to be honest I cant find them, certainly not where you would expect them to be, the only thing I have got is a pressure sensor on each air box

 

[television]

Good reason why you cant see one, it has not got one.

Just been looking and there are extensive test that can be done on STAR and loads of things to give miss firing.

You first move must be to get plugged into STAR

 

[guv]

Good reason why you cant see one, it has not got one.

Just been looking and there are extensive test that can be done on STAR and loads of things to give miss firing.

You first move must be to get plugged into STAR

Yes MB did a short test and confirmed that the coil packs are causing the misfires, but I am not convinced, and I am unwilling to spend 2k + for them to tell me its something else, when the faults is still there, as I have been down this road with dealers many times.

 

[television]

Then a good indie is a better way to go

 

[kontax25]

Then a good indie is a better way to go

just change sparck plugs. NGK http://www.ngk.com/results_app.asp?AAIA=1431946

 

[amwebby]

I had thìs problem. Turned out to be an upstream O2 sensor.

 

[LYNALL]

Surely a 6.0 litre twin turbo v12 must have more than 500bhp?

No insulting you or anything just doesnt sound enough.



Lynall

 

[type49]

Surely a 6.0 litre twin turbo v12 must have more than 500bhp?

No insulting you or anything just doesnt sound enough.



Lynall

This is probably a measurement at the wheels. You could "lose" about 16% through an autobox & diff.

 

[type49]

Do you know for certain that the plugs were changed & if so, were all 24 red surpressors also replaced, as MB state they must be replaced with plugs. Also check oil pressure switch isnt leaking engine oil internally into loom.

 

[Cole@MBS]

Do you know for certain that the plugs were changed & if so, were all 24 red surpressors also replaced, as MB state they must be replaced with plugs. Also check oil pressure switch isnt leaking engine oil internally into loom.

Forgot about that old chestnut!!

Not seen a loom change on one of those for a few years!!

 

[type49]

Not seen a loom change on one of those for a few years!!

Dont ****** want to see another one!!!