how does this spark plug look?

[DavidT]

It is Motorcraft.
It is one year old (10K miles).
Is the blak build up normal?
Does the tip indicate any rich or lean a/f?
TIA.

 

[Machspeed]

Looks ok in that pic.

 

[masho95]

Looks pretty good to me from that picture. The electrode seems good without any major discoloration.

 

[AutoSHO]

Looks a little lean if anything. The electrode and tip looks pretty bright white.

 

[shobikes]

DavidT:
Is the blak build up normal?
Does the tip indicate any rich or lean a/f?
TIA.

The black (carbon) buildup is normal for an engine that burns a little oil. What's your oil consumption like? You either have slight blowby or marginal valve stem seals. Neither is a criticl condition.

The tip looks a tad lean, but on these cars, so long as the O2 sensors are operating correctly, it's hard to judge mixture by plugs. The engine will tend to run as lean as it can to reduce emissions w/o knock or loss of power.

 

[sdpatt]

The oxygen sensors are much better at reading the instantaneous fuel mixture than by looking at the conditions on the plug - if they are working properly. Here is one site for reading plugs, but as long as the engine control system is working, the mixture is controlled to oscillate around 14.7:1 by the EEC.

Emissions controlled engines are not allowed to run lean due to the generation of large NOx components. Here is a good discussion of the workings of modern engine control systems.

 

[shobikes]

Interesting! Learn something new every day...

The spark plug site looks like it was cut & pasted out of the front of a Haynes manual.

The emissions site will become bookmarked on my browser! Thank you, Mr. Patterson.