Destroyed spark plug???????

Evening all,

Finn thanks for the help and Drew thanks for the part and the advice....appears you were correct with the misfire.....disconnected the leads from the coil pack one by one while running and when disconnected the front nearside one ....no change. So i removed the spark plug and its is destroyed...... the one on the left is the plug from the nearside front bank and the one on the right is from the rear nearside bank...... anyone got any idea how this could get like this? or would it just be a dodgy plug?

www.hodgsonuk.com/david/sparkplugs.jpg



Cheers

Dave H

very old plugs or running very lean or very rich

bloody hell , first time av seen a plug do that

has the tip actually melted?

some hellish gapping on that!

seen it before on a astra gsi when customer was running car with *ucked lambda sensor
only prob u may have is were has the tip gone ? could be stuck to piston top , exeted through turbo blades , happens when cylinder temps exeed limmit . realy suprised it has not cooked a piston or two

yup they do it when running lean, if you check your piston you will probs see aload of detination, lukly the car hasnt locked up

Morning, aye the end has actualy disintigrated....theres nowt left of it! I was thinking the same thing ohhhhh shit where has the end gone i am off for some new plugs this morning as we need the car (snow) so the engine will probably blow up next week

Cheers for the replies lads....

new plugs wont help, if the engines running lean

It may have only been a faulty plug!

Seen it happen with champion plugs in my old RS's and cossies but never seen it with NGK's.

Did it have the correct plugs fitted in the first place?

It should have had NGK PFR6B or PFR7B plugs fitted.

Well worth getting it checked for det/correct Afr's to be sure it's running correctly, also worth putting a scope down to check the piston condition to know for sure.

Andy Kindon has a scope and a wide band for checking AFR's so will be worth giving him a shout to give it a once over.

I will be dropping my det cans off with him on Monday so he will have the full kit for checking your car this week.

Jonny Gav wrote:

It may have only been a faulty plug!

Seen it happen with champion plugs in my old RS's and cossies but never seen it with NGK's.

Did it have the correct plugs fitted in the first place?

It should have had NGK PFR6B or PFR7B plugs fitted.

Well worth getting it checked for det/correct Afr's to be sure it's running correctly, also worth putting a scope down to check the piston condition to know for sure.

Andy Kindon has a scope and a wide band for checking AFR's so will be worth giving him a shout to give it a once over.

I will be dropping my det cans off with him on Monday so he will have the full kit for checking your car this week.

Cheers Jonny,

Aye they were the NGK platinum i got em from Camskill last year off the "impreza" page so i assume they were correct .... i have a scope so im going out now to stick it down for a look.... if the piston is fooked what then! new pistons i presume.....?

Yeah, check all round the edge of the piston for damage and the piston crown for poc marks (sign of det) also a clean carbon free piston is a sign of det.

If all ok then still get it checked for fueling and det though.

From the photo of the spark plug it doesn't look melted, can you see any signs of melting on the ground electrode?

Jonny Gav wrote:

Yeah, check all round the edge of the piston for damage and the piston crown for poc marks (sign of det) also a clean carbon free piston is a sign of det.

If all ok then still get it checked for fueling and det though.

From the photo of the spark plug it doesn't look melted, can you see any signs of melting on the ground electrode?

No melting at all it looks more like the middle has disintegrated nothings melted at all - here a pic i just took of the top of the piston dont look good or does it?

www.hodgsonuk.com/david/piston.jpg

This is what a damaged piston looks like, can't see any damage on the crown of yours from that pic.

Jonny Gav wrote:

This is what a damaged piston looks like, can't see any damage on the crown of yours from that pic.

phew....no it lloks nowt like that thank god....i am just putting the new plugs in now i think the plug may have been dodgy ...do you think the part thats come out will have just burned up or may it have gone through the exhaust valves....i am just worried about the turbo thats all...

The tip of a plug is small so can easy go through the exhaust valve and the turbo without touching it or causing any damage, if it jams in the valve seat it could stop the valve from closing properly but that will become clear when you start it up with the new plugs in, if it has jammed in the valve seat there will be no compression so it will sound like it is running on 3.

Doubt something so small would have any effect on the turbo exhaust wheel to be honest.

Jonny Gav wrote:

The tip of a plug is small so can easy go through the exhaust valve and the turbo without touching it or causing any damage, if it jams in the valve seat it could stop the valve from closing properly but that will become clear when you start it up with the new plugs in, if it has jammed in the valve seat there will be no compression so it will sound like it is running on 3.

Doubt something so small would have any effect on the turbo exhaust wheel to be honest.

Cheers Jonny, thats what i like....positive reassurance i will let you know.

thanks mate

SORTED !!! (for now at least) TBH prob nees Re-map got no cats and blitz induction etc etc ...

cheers for the help lads.

Glad ya sorted, defo sounded like a miss from wot ya discribed yesterday

drew wrote:

Glad ya sorted, defo sounded like a miss from wot ya discribed yesterday

Cheers Drew ...looks like you were spot on mate.

I took her out earlier and pulled on the main road (covered with snow) and put my foot down like i have been doing the last few days (running on 3 cylinders ) but this time she took off like a fooking rocket .....sideways......

Our lass was not impressed i got a torrent of abuse off her saying "you did that on purpose!" i protest my innocence but wellllllllll....maybe i did