Thread: What are the correct NGK spark plugs for the M62 4.4.V8?

I put in 25 litres and I thought (probably wrongly) it was better. I didn't notice any pinking.

I put Autologic on it again today and read faults - Persistent misfire on #2 but also misfires on every other cylinder.

I'm thinking of refitting the previous spark plugs.

Fixed! But not necessarily solved.

As I said, I cleared the faults and today had more misfiring and check engine light flashing. So I connected Autologic** once more and, yet again, cylinder no. 2 was the source of the persistent misfire.

I pulled the coil off (easy to do as I've left off the plastic covers over the plug area while I'm testing) and replaced it with a spare. All fixed. No more misfire and it was really, really bad prior to that.

Now why am I unsure if the coil is faulty? Well, cylinder 2's (and cyl no.6) coil has a brown (earth) wire coming out of the loom with a terminal on it. It, plug a braided lead to the head both are supposed to go onto one of coil no. 2's mounting bolts.

When fitting the new one today I realised I hadn't put those ont the mounting bolt - and I couldn't remember removing them when I pulled the old coil off. Dunno if it makes a difference but that appeared to be the main earth point for all the injectors on Bank 1. Maybe I'll disconnect them and try it again with out the short earth. There is another earth way back in the loom/engine management ECU.

** I used Autologic because my GAP IID Tool wouldn't connect to the engine management ECU to read/clear faults. I'm not sure why. I'll try it again in a couple of days. I could have used RovaCom or Testbook but I'd have had to extricate Testbook (T4 actually) from the depths of the garage. The Rovacom Faultmate software is on the same computer I use with T4.