In the course of investigating a dead miss on 4 cylinder I pulled the spark plugs which, after less than 10,000 miles looked pretty fouled. My car has bad valve seals and the first few seconds after it starts up lays out a blue cloud. After that, there's no visible smoke on either acceleration or deceleration. Given the number of different spark plugs out there (Copper, Platinum, iridium), I was wondering if one type would be more resistant to fouling than another. Ditto the heat range. (I would have the valve seals replaced, but the cost I've been quoted, $ 3,000 to $ 3,500, buys a heck of a lot of oil!).

 

Is there any particular type of spark plug (Copper, Platinum, Iridium) less prone to oil fouling than others? My car has bad valve seals and although I haven't had a problem as yet, the spark plugs look pretty bad.

 

Hi. My friend working as the serviceman on Jaguar service station in Germany recomended to use spark plug made from NGK.

 

Conventional wisdom was to use a spark plug 1 to 2 heat ranges higher than the one recommended by the manufacturer.

The premise is that a hotter plug heats up quicker and would be more likely to burn off oil deposits on startup and extended idling, which is where most of the fouling is going to occur.

I'll let someone else speak to any detriments of using a hotter plug.