How do these spark plugs look?

How do these spark plugs look?

Author
Discussion

gotoPzero

Original Poster:

18,949 posts

203 months

Tuesday
quotequote all
I have a feeling my spark plugs might be fouled?

What do we think?

The left bank, second from bottom smelled very strong of fuel. The rest were ok smell wise.


E-bmw

10,898 posts

166 months

Tuesday
quotequote all
TBH they don't look in the slightest bit fouled or anything else negative apart from old.

gotoPzero

Original Poster:

18,949 posts

203 months

Tuesday
quotequote all
Hm. Ok.

I have a misfire at idle and low revs. (sub 2500)

Runs fine at higher revs. (over 2500)

Coil packs tested ok.
I cant see any physical issuses.

Only thing I have done is filled up with BP where as I almost always use Shell - but I cant see it being bad fuel as it would run badly at all revs?

Would you replace the plugs anyway - they are c.5-6 years old maybe. Done max 2000 miles.

MK3 Dan

310 posts

159 months

Tuesday
quotequote all
They look fine but for a misfire like that I would be replacing them to see if it resolves the problem.

We use Iridium plugs in some motorbike engines and if you 'foul' one or it goes off no amount of cleaning etc will ever seem to get them back however a new set of plugs sorts the problem.

gotoPzero

Original Poster:

18,949 posts

203 months

Tuesday
quotequote all
OK cheers I was thinking it was about due anyway - so will give them a go.

GreenV8S

30,774 posts

298 months

Tuesday
quotequote all
Why are they all so rusty? That is not at all normal, especially on relatively new and low mileage plugs. Do you have a water ingress problem? Damp ignition components are a recipe for further problems.

gotoPzero

Original Poster:

18,949 posts

203 months

Tuesday
quotequote all
Open engine bay so you get a lot of water in there when it rains.

There is a gasket around the spark plug covers but its paper and the engine runs hot hot, so after a while water can get in as the gaskets are basically useless.

I do try and keep a plastic sheet to cover the engine at car shows etc but there are times it gets wet.


SystemOfAFrown

83 posts

34 months

Tuesday
quotequote all
gotoPzero said:
Coil packs tested ok.
How have you tested the coils?

gotoPzero

Original Poster:

18,949 posts

203 months

Tuesday
quotequote all
SystemOfAFrown said:
gotoPzero said:
Coil packs tested ok.
How have you tested the coils?
I have spares.

LunarOne

6,264 posts

151 months

Tuesday
quotequote all
Is the centre electrode supposed to be that pointy? In every plug I'ver ever seen, they have a flat top giving an even gap between it and the ground electrode.

paul_c123

631 posts

7 months

Tuesday
quotequote all
The tips look fine but I'd replace them due to the corrosion on the hex portion. You don't want to replace a plug then in a year or so, try to undo it and have it snap.........

paul_c123

631 posts

7 months

Tuesday
quotequote all
LunarOne said:
Is the centre electrode supposed to be that pointy? In every plug I'ver ever seen, they have a flat top giving an even gap between it and the ground electrode.
Pointy can be normal.

stevieturbo

17,741 posts

261 months

Tuesday
quotequote all
LunarOne said:
Is the centre electrode supposed to be that pointy? In every plug I'ver ever seen, they have a flat top giving an even gap between it and the ground electrode.
every modern precious metal plug for the last 30 or so years is like that, platinum, iridium etc.

E-bmw

10,898 posts

166 months

Wednesday
quotequote all
LunarOne said:
Is the centre electrode supposed to be that pointy? In every plug I'ver ever seen, they have a flat top giving an even gap between it and the ground electrode.
I am guessing they are Iridium or similar.

Iridium plugs are all "pointy".


keo

2,475 posts

184 months

Wednesday
quotequote all
Open engine bay V8, what car is it out of interest? As others have said plug tips look pretty normal to me but I would replace them because of the rust giving a headache further down the line.

gotoPzero

Original Poster:

18,949 posts

203 months

Wednesday
quotequote all
90s Ferrari. The engine cover is basically mesh. There are water deflectors but they only really make it worse!

Panamax

5,940 posts

48 months

Wednesday
quotequote all
Spark plugs can look fine but be failed internally. Trying a fresh set of plugs definitely wouldn't be wrong. The plugs may be old even if the mileage is modest. Are they the correct spec' for the engine?

There are spark plug testers you can buy. How much use they are I don't know.

LunarOne

6,264 posts

151 months

Wednesday
quotequote all
Panamax said:
Spark plugs can look fine but be failed internally. Trying a fresh set of plugs definitely wouldn't be wrong. The plugs may be old even if the mileage is modest. Are they the correct spec' for the engine?

There are spark plug testers you can buy. How much use they are I don't know.
Yep, just had a 1 year saga of trying to get my motorbike back on the road after a number of years laid up because of this. The plugs looked fine and only had a few thousand miles on them. They tested fine for resistance, but two of the four wouldn't generate a spark when they got warm. Which boggled my mind. I had taken off the airbox, the throttle bodies, cleaned out the injectors, tested all the sensors, rmoved the tank, tried to remove and test the fuel pump inside the tank. Was a nightmare and all it needed were new plugs!

Peanut Gallery

2,575 posts

124 months

Wednesday
quotequote all
I had similar - stutter when below 2k rpm, clear above - one of the plugs had electrical tracking showing in the ceramic, so the arc was going around the outside. Cleaning the ends of the leads and outside of the plugs temporarily sorted it, new set of leads and new plugs properly sorted it.

jollysoutherner

163 posts

237 months

Wednesday
quotequote all
Have you checked they are the correct gap?