Hi all,
First drive of the kit this year and the engine (SAAB B204) was good round town but spat and popped if I put my foot down, so went home for a peek.
Couldn't muster the enthusiasm to look at fuelling/map so went for the easy look at spark plugs first. I'm glad I did as 2 of the plugs had next to no ceramic(?) left on the top half, it was all rattling around in the plug hole (hoovered out) and the other two were cracked.
I was wondering what could cause this as they were brand new NGK of the correct type that I put in a week before I laid the car up last october (car lives outside under a canopy).
They were off Ebay so could've been cheap chinese copies I guess? and the car was running warm last year, although I only did about 200 miles and it never actually overheated, just bad airflow into the rad (now sorted I think).
Pretty sure I didn't overtighten them either, done up by hand then 1/4-1/2 a turn.

Cheers for any ideas
Kev

[Edited on 2-4-12 by flibble]

Maybe the plugs are getting too hot? i.e engine running lean? Any undue vibration when driving?

Just my 2p worth

So it's the ceramic on the exterior thats breaking up?

Sounds like you bought fakes to me. Only other thing that would be suspect is your tightening.

Did you use a plug spanner/socket with a rubber insert ---- if so pull the rubber out with pliers and throw it to b+**-%Yy.

Yes, it's the ceramic/white bit on the whole top half of the plug thats broken
I have a wideband and an EGT and they both have been reading fine (hard to look when driving but pretty sure), it was just the water temp hitting 110 on occasion last year.
No rubber bits in my plug spanner!
Hoping they were cheap knock off if there is such a thing! Will buy some more when I find a shop in town that sells NGK and doesn't insist on selling Champion crapola plugs.
It's just something I'd never seen before, had me a little perplexed.
Cheers all!

Edited for crappy pic, can't find the decent camera but you get the idea. Also hard to see the cracks in plugs 2 and 3, plug 4's ceramic is just resting against the plug shaft, it looks the same as plug 1.


[Edited on 2-4-12 by flibble]