Mucky Spark Plugs - 2.0 Jts

[Alfa156Melb 9]

Smaky, after MES throwing a PO304 fault, I've replaced my number 4 coil pack and decided to replace all the spark plugs while I was at it just to be sure.

 

To my eye, they look fairly dirty - not too bad but there's certainly carbon there.. The engine is running fine, nothing stands out other than maybe a lack of power over 4000RPM. I suspect that will be carbon build up in the inlets. Anyway, there's no symptoms, I'm just interested in your feedback.

 

Most of my driving is highway or open road: 80 - 100kph.. and a small amount of city driving. I rarely drive the car hard (Fuel prices!) and really never red line it. Have a look at the pic, I'd appreciate your opinion..

 

A possible cause of the carbon, apart from it being a JTS, is my thermostat.. on the gauge I get 70 degrees, on MES it's perfect: 80 - 90 degrees. I'm inclined to believe MES and suspect a lazy temp sensor on the thermo.. Anyway, I thought it worth mentioning..

 

Edited August 14, 2012 by Alfa156Melb

[Smaky 73]

That plug looks OK, it's the right colour and the soot on it is normal, so look closely at the electrode, has it gone into an oval shape? Otherwise I'd still use it.

 

P0304 is normally accompanied by a P0300, in which case the normal suspects are loose coil pack plug or a faulty coil pack itself, it's rare for the plugs to cause it.

[Alfa156Melb 9]

The electrode looks good...

 

I only changed them because having recently replaced the engine, not knowing its full history.. and they werent expensive.. so why not.

 

A P0300 was there, along with a P0304.. so replaced the coil with a new one.

 

Anyway, that's good news.. happy days

[Alfa156Melb 9]

Just took the car for a run and for some reason it feels more lively.... I didn't expect that..

[Smaky 73]