Spark Plugs - Oil Fouled Casuing Misfire?

Spark Plugs - Oil Fouled Casuing Misfire?

Author
Discussion

Teocali

Original Poster:

235 posts

186 months

Tuesday 16th December 2014
quotequote all
Hi all,

Looking for some guidance. Background is misfire (ECU shows cylinder 3) - cyclinder 4 spark plug seems to show oil fouling?

Astra - Oil Fouled? by mongooseteocali, on Flickr

Where the other three show ash deposits:
Astra - Ash Deposits by mongooseteocali, on Flickr

Some light mayo on the filler cap - planning to check compression tomorrow.

Game over or change spark plugs and re run? What could be causing the deposits / oil?

Appreciate any comments, Sam

powerstroke

10,283 posts

159 months

Tuesday 16th December 2014
quotequote all
Would guess the oiled plug is out of the worst cylinder of an engine that's burning a lot of oil! the other plugs are still firing hence the ash deposits , maybe lucky and its just the breather pcv system blocked, otherwise might be valve stem oil seals or ring/bore wear ..

CrutyRammers

13,735 posts

197 months

Tuesday 16th December 2014
quotequote all
Yeah, more likely to be a symptom of the misfire rather than the cause I'd say.

Teocali

Original Poster:

235 posts

186 months

Tuesday 16th December 2014
quotequote all
Thank you both.

Would I be correct to assume that a compression test will tell me whether it's the pcv or seal stems/bore wear?

powerstroke

10,283 posts

159 months

Tuesday 16th December 2014
quotequote all
Teocali said:
Thank you both.

Would I be correct to assume that a compression test will tell me whether it's the pcv or seal stems/bore wear?
If the compression is low then its a good bet its bore and or rings otherwise I would pull the cam cover give it a good clean if there is a build up of gummy sludge blocking the breather ,it also might point to lack of regular oil changes old oil goes acidic which with heat hardens and rots oil seals ..

Edited by powerstroke on Tuesday 16th December 14:59

SuperchargedVR6

3,138 posts

219 months

Friday 19th December 2014
quotequote all
My old Alfa 147 2.0 Twin Spark had plugs like the bottom pic - all 8 of them. That thing drank a litre of 10W/60 a week. It never kicked out any blue smoke though.

The top pic resembled my old Allegro's plugs. That thing drank a litre of Duckhams Hypergrade 20W/50 a day. God I hated the 1275 A series. A hateful little engine.