gmcclurg

I finally changed the plugs yesterday. I do not how old they are. Here is a picture. No oil on them but they all had some buildup of crud. #2 - top right was really bad. Sort of a pinkish buildup. Any idea what its from? The car does run much better now.
Thanks

Paul L

I would guess sulphur in the gasoline.

TedH

Lead deposits perhaps? According to Chiltons: "Ash deposits are characterized by light brown or white colored deposits crusted on the side or center electrodes."

More: "Ash deposits are normally derived from oil or fuel additives burned during normal conbustion. Normally they are harmless, though excessive amounts can cause misfiring. If deposits are excessive in short mileage, the valve guides may be worn."

Smokehouse69

Probably additives, specifically MTBE (methyl tertiary-butyl ether) which is used in a great portion of the country during the winter. It is some nasty stuff that is probably more dangerous than the pollution it is supposed to prevent.

JB

:iagree: What Smokehouse said, esp. since you're up there in the great white north.

JB

gmcclurg

Thanks for the input. So, I guess, the answer is - don't buy any gas in the winter.

Fevre

I have the same crude on my plugs, I was sure it was from leaking valve stem seals but now I am not sure. :confused: I also have a slug/goo build up on the intake valve flow side which looks like very thick oil so I am still leaning toward valve stem seals.

wcsinx

:iagree: Yup, turns your plugs a pinkish red. It's not necessarily limited to winter gas either. I've seen it on several Florida cars.


[Modified by wcsinx, 5:11 PM 9/15/2003]

77-C3 & 89-C4

It could also mean your timming is off. Keep the plugs and show them to a good mechanic.