L322 4.4 M62 Sudden lumpyness Misfire in Cyl 7

awkwardbob · Wednesday at 18:56

Hi,

So having waxed lyrical only yesterday as to how smoothly my L322 was driving, it decided to bite me on the ar*e today.

I jumped in to run an errand and it didn’t feel at all well, a bit ‘bouncy’ and rough. Going to full lock on steering made rather worrying ‘chirping’ noises and then the amber engine light started to flash.

Gap IID reports:
0x43E P0000 multiple Misfire fault
0x438 P0000 -Misfire detected cylinder 7

I’ve decided not to drive it any distance and will ask the AA to bring her home so I can have a look at her.

I’m guessing the most likely candidates might be the plug and / or the coil pack ?

What else should I check or is that a sensible place to start ?

Also…. I did have an issue the other day where I was running on fumes (the range dropped drastically from 14 miles to 1 in a mile or two) so I was a little worried that I may have dredged some fuel tank gunk through the system. Garage suggested changing the fuel filter but would t that affect all cylinders.

Thanks again for your help

Bob

biketeacherdave · Wednesday at 19:55

As you say...plug or coil pack the m62 is a pretty simple engine and your fault code is telling you no7.
Coil pack failure is common so is oil down inside flooding the coil pack causing misfire issues usually caused by failed gaskets on valve covers also very common.
Pull the coil pack and inspect

awkwardbob · Wednesday at 20:32

There are the inevitable oil leaks (and a smell of burning oil) so I’ll have a look at the rocker cover gaskets too.

Mark Piercy · Thursday at 07:56

In addition, you can remove the suspect coil pack and swap its position once any oil is cleaned if found. Clear the codes and see if the problem moves to another cylinder. The oil in the plug holes is a good cause of miss fires

awkwardbob · Saturday at 13:15

Ok,

So I changed the coil and plug in cylinder 7.

Access wasn’t fantastic but it was reasonably straightforwards. The plug that came out was a bit rusty but not sooty and no significant oil in the spark plug well.

Replaced with a Bosch coil and NKG Platinum plug.

After the change the engine is as smooth as a hot knife through butter.

Thanks for all the help

Mark Piercy · Saturday at 13:23

No significant oil?
So there's oil?
Rusty spark plug !!
I don't think your done there matey.

Dippypud · Saturday at 13:39

Mark Piercy said:
No significant oil?
So there's oil?
Rusty spark plug !!
I don't think your done there matey.

Swap out a few more plugs, check what you pull out and keep for 'emergency' spares ...

biketeacherdave · Saturday at 14:46

Oil is oil is shouldn't be in there as said maybe do a service all new plugs gaskets to prevent oil ingress etc

awkwardbob · 2025-03-02T18:41:09+0000

There was a slight ‘misting’ of oil on the underside of the cover but no evidence of a leak from the rocker cover on that side.

Haven’t looked at the other bank yet.

Will look into the rocker cover gaskets -I worry they may be pushing my spanner skills

awkwardbob · 2025-03-02T19:51:31+0000

Here’s the plug I took out… AC Delco R7602
Replaced it with an NGK Laser Platinum BKR6EQUP3199

Mark Piercy · 2025-03-02T20:07:53+0000

awkwardbob said:
Here’s the plug I took out… AC Delco R7602
Replaced it with an NGK Laser Platinum BKR6EQUP3199

View attachment 336298 View attachment 336299 View attachment 336300 View attachment 336301

Your cat certainly ain't impressed either

awkwardbob · 2025-03-02T22:07:37+0000

Nothing impresses her -except treats !

L322 4.4 M62 Sudden lumpyness Misfire in Cyl 7

awkwardbob

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biketeacherdave

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awkwardbob

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Mark Piercy

Well fumbled member....

awkwardbob

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Mark Piercy

Well fumbled member....

Dippypud

Never Knowingly Understood

biketeacherdave

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awkwardbob

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awkwardbob

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Mark Piercy

Well fumbled member....

awkwardbob

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