cavity where the sparkplug sits is brown?

Jagger · Post by **Jagger** » 24 Nov 2009, 03:40

I changed the sparkplugs and I saw that the second cavity had a brown colour compared to the clean aluminium shade of the other 4 cavities.
By checking the old sparkplugs I couldn't make out any difference in appearance. All of them looked the same, dry, a light brownish deposit but just a thin layer. To me they looked ok. I was just wondering where the brown deposit in the cavity comes from. Any clue?

Regards, Jagger

Checksix · Post by **Checksix** » 24 Nov 2009, 22:48

What else but a leak?

Jerry

Jagger · Post by **Jagger** » 25 Nov 2009, 02:36

Hi Jerry,
thanks, you are right, my concern was more if that indicates a problem?
Most probably the sparkplug on that cylinder was not tightened properly or the seating was not properly clean and the smoke came into the cavity.
Could that have damaged anything? Must I check on something particular? I am just concerned as I only bought the car 4 months ago.

Jagger

Checksix · Post by **Checksix** » 25 Nov 2009, 11:37

I concur, the most likely suspect is the plug torque. Add an oil leak via spills while refilling and a few other possabilities. I doubt it would be of any concern that may cause damage. Possibly put a bit more stress on the coil pack, but I doubt it. I wouldn't worry, keep on driving and stay current on maintenance items. You didn't mention the model and year and mileage. Just out of curiosity it's nice to know. It could be a model that doesn't have coil packs!

Jerry