Right..i been out ragging the car yesterday ...Took spark plugs out today.....

3 were lovely grey/brown perfect

No 2 (on plug lead) was looking more whitish now i did notice that the gap was a tiny bit bigger than the rest.

So:-

Can gap if open slightly more cause a colour change?

Could that plug be failing at all?

Is that no 2 cylinder prone to run more lean than the rest?I did have a seal leak on that injector in the inlet manifold before...but i put a new seal and that seemed to cure it....(as it caused onboost misfire)..any other reasons????Fooked injector..any tests i can do?

 

red coating- additive in fuel
black fuel fouled- wrong heat range or too rich
oil/ash fouled white ash- oil seal leaking
black carbon fouled- too much low speed driving or heat range wrong

other than that don't worry

 

i was wondering this...

mine come out pretty white electrode, with black base and around the thread area.

 

thought no3 piston was the iffy one

 

Phil,
If this is the cylinder that had the air leak, then it obviously still has one...

If it is nothing to worry about, then it will be the same colour as the others after you have matched the gap. If it isn't, then it is either getting more air or less fuel than the others.

 

Sorted

The std injector next to the leaky grey was er leaking so new seal all sorted..idles properly cold now too ....Hope i didnt do any damage on No 2 But i guess if its now fixed and its still on 4 no probs it survived,plus the fact there was no misfires and that plug aint what i'd call really lean..just leaner than the others..LOL ...i looked at the piston down the plug hole and it looked the same as all the others..fine...although cant see that much..lol.

 

I hope you examined it properly!! and used a torch!!

 

Good job you actually listened to me for once .

 

Red colour - Additive in fuel, sorry if this is a daft question but what would be the additive?

 

Red diesel

 

red paint