No Guts

[MrT]

My V6 is different as it has one coil per plug, but even if yours is as you suggested where one coil serves two cylinders and it sparks near the top of every stroke, you can still have one faulty spark on one cylinder.

 

All the doubling up does is make one spark for every revolution rather than every two and one electrical path to the spark plug can be damaged so that one cylinder never gets a sufficient spark but the other paired one does. Of course you could have a double failure from a single coil fault or a single lead fault where one shorted to earth lead takes out the other paired ones spark. If the firing order is ABCDEF, the pairing would normally be AD,BE & CF.

 

Again mine is different, but when I had one coil pack fail out of six, my engine management warning light came on and VAGCOM read the error as "misfire detected on cylinder X".

 

Also when I lost one cylinder due to a coil failure, it was not blindingly obvious, the car still drove well on five cylinders, it just lacked a bit of power and idle was not as smooth as usual. I finished my holiday with bikes on the back, roof and a roofbox.

[dipsomaniac]

car is running rough. black plugs on cylinders 1 & 5, others ok. two faults logged:

1. 00525 - oxygen sensor g39
   
2. 00533 - idle air control regulation
   

would the oxygen sensor cause the problem or is it a casualty? anyone any ideas on the 00533 fault?

[sepulchrave]

Oxygen sensor (lamda probe) is probably sooted up, and the ECU thinks the car is stuck on choke because of the unburnt fuel in the exhaust.

 

May I humbly suggest (finally, and for the last time) that the HT circuit is at fault somewhere, then I will go away and NEVER darken your doorstep again with suggestions that you just don't wanna hear! :blink:

[dipsomaniac]

its not that i don't want to hear supulchrave its because i don't think it is the coilpack. i may be wrong but it makes sense that it is unlikely to be the coilpack with a misfire on 1 & 5 only.

[Guest 3.5bullet]

its not that i don't want to hear supulchrave its because i don't think it is the coilpack. i may be wrong but it makes sense that it is unlikely to be the coilpack with a misfire on 1 & 5 only.

 

 

why? the only link between 1 & 5 is the coil pack!

[dipsomaniac]

i need to try to find out why the 2 sensors are outside of there parameters then i will try to source a s/h coilpack.

[dipsomaniac]

a huge slice of humble pie please supulchrave - it was the coilpack, colonel mustard in the study.

 

for the record

 

Unfortunately, i was thrown off the scent in the first couple of days. firstly, by a local mechanic who guaranteed 100% that it was not the coilpack. Secondly, by another forum who suggested that it could not be the coilpack with a misfire on cylinders 1 & 5 as they are triggered by 6 & 2.

 

If you have the same symptoms and no RELEVANT fault codes are logged you need to first try to establish a really good (must jump at least an inch) spark at the plugs. if no spark or a poor spark you then need to rule out plugs and ht leads before trying to establish a lead (electric pulse) from the ecu to the coilpack with a multimeter. if there is a lead to the coilpack it is 99% certain to be coilpack.

 

dealer wanted

[sepulchrave]

n.p. dipso, glad you got it sorted. In my experience the vast majority of "mechanics" are just bloody fitters, and crap ones at that! ;)