I switched to platinum plugs about a month ago. I have a misfire problem and I was checking the temp with a infared heat gun at the headers and cylinder 2 was 100 degrees less than the rest. I pulled the plug to check it out and it looked clean but had this brown chalk coating with oil or carbon around the ring. I wanted to compare plug 2 and 1, but the #1 looked just the same. Is this normal or do I have a spark or fuel issue?

Heres pics: https://picasaweb.google.com/1121999...46204467750050

 

heres a deal on plugs i found.

 

I just remembered I Seafoamed the car, and have also used octane booster and injector cleaner. That might be the reddish brown colour. As far as the oil or carbon around the ring, I dont know...

 

....Why?

 

read/look at the ash deposit one. the pic is the extream, im thinkin yours is short term.

 

Not all cars can handle platinum plugs. It's one of the most common mistakes made. I have a 98 v6 and I run iridium plugs. If I remember correctly, iridium plugs are stock and recommended for both the v6 and v8 Camaro. They burn hotter that platinum plugs and have a longer life. They are also more expensive. $12 a pop if I remember correctly. The first thing I would do is to make sure they plugs you have are recommend for your car.

 

Does you car still have the orange/brown coolant in it? You know a small leak in the head gasket can cause a Random missfire by shorting the plug.

 

huh?

I'm running them in 7 vehicles and 1 marine engine

I don't know what I have in my weed whacker, chain saw or lawnmower but think they are copper as i haven't changed them in a while

 

There are some cars out there that don't like the platinum plugs, but there are others that work excellent with them. Between copper, platinum, and iridium, platinum is the worst, but not for the reasons you mentioned. Platinum gives low spark energy while maintaining a average life. Copper gives a very strong spark, but it's downfall is life. Iridium has a little less of a spark than coppers, but it's life can go for 100k miles. There is much debate on copper vs iridium as far as cost effectiveness goes, but that is for another time.

 

With the modern high energy ignition systems the problems encountered with low grade spark from the characteristics of Platinum plugs is about nilch. If you really want to see the platinum problem then get an old 50's or 60's vehicle with point type ignition and see how crappy they run with platinum plugs. The 98+ 3.8L and all LS series engines run from the factory with Iridium plugs. The ACD iridiums and NGK both have a center electrode design that improves the burn of the fuel and creates a more round flame kernel.

Your plugs look OK but with a fuel injected engine you should have a more white looking ceramic. The reddish color is usually caused by a fuel additive in modern fuel and back in the day the lead in the fuel would cause it. The last time I did plugs in my Camaro the ceramic was a greyish white and the plugs were in the engine for about 1.5 years.

Massey