I noticed that two of my spark plugs were whiter than the rest when I replaced them along with coil packs.

Does this look like a leaky fuel injector O ring causing those two cylinders to run lean? Engine doestn have fault codes and car drives fine.

Anything I should look out when replacing these O rings?

Thanks!
J

 

Why do yo jump so quickly to thinking injector o rings.
Are you having driving issues
Are there any misfires
Have you had the ECU read out with VAS or equivalent.
If your cylinders were misbehaving the event would show as a code. The ecu can determine which individual cylinder is not firing correctly.

TBH it doesn't look that bad to me. No signs of glazing or burnt electrode. No heat cracking.
Did you find this on a routine plug change or were you taking them out for another reason?

 

Hi Sunnyside

There was a slight hesitation at WOT but no error codes after a vagcom scan.

As sparks nor coil packs had not been changed I decided to replace them all. The hesitation problem is gone and car pulls strong and smooth.

Checking the sparks I noticed two were whiter than the rest so possibly burning leaner as aged O rings (MY07 car) could let in air.

I'm looking at more preventive maintenance for the GT now as its only a weekend car.

Thanks

J

 

I would replace all the O-Rings if I were, not an unreasonable assumption. Maybe also check you are replacing your spark plugs with the correct model # and are gapped properly-on high performance engines like these it does make a difference. What cylinders were these from?

 

However, what initially is the reason for assuming o rings. Has this happened before? What it just a guess or does the op have experience of this happening before?
2 injectors leaking is a bit of a coincidence unless they have been removed at some point and not put back correctly for eg.
I would also have expected to perhaps had other symptoms such as blow by when on boost. Possibly even a small amount of fuel being blow out the injector seat on boost and perhaps a lean cylinder code. And tbh it doesn't look all that bad from the photo.As you say, gaps on plugs but are all the plugs the same heat range? These might very well have been like this since the last plug change. I suspect if there is no other symptoms and fault codes and it has only been notice on a plug change then the chances are all ik OK
.
I'm quite interested in finding out the results of this though.

 

Hi Peter/sunnyside

Unfortunately I didnt take note of the spark plug order nor which cylinder they were removed from. All spark plugs removed and installed are the NGK R # PZFR6Q11 which cross ref to the Bentley 101905600B plug.

I decided to replace the spark plugs/coils due to the fact they were never replaced since car ownership and the hesitation issue I was experiencing.

DIY replacing fuel injector O rings will be a cheap solution if it resolves issue and good preventive maintenance.

Attached photo shows some spark plugs pulled from a friends flying spur. I dont have the full picture showing all 12 but if these are pulled from bank 1 it seems cylinder 1 and 5 show whiter tips vs others.

Thanks

J

 

Looks like that's what these cars do then. I wouldnt worry and as you say , if changing the o rings is something you can do , might as well do it then just to be safe.

 

I agree, almost exactly with what Sunnyside here has said

 

Nothing wrong with replacing the injector o-rings. Although you would likely be able to tell if you had a leaky o-ring since the injector cups (plastic pieces that house the injector in the intake manifold) would look dirty. If you notice some are clean and others are dirty that would be an indicator you have leaking o-rings.

Hope this helps!

 

Cool...thanks everyone.

J