[200q20v] Reluctant Spark Plugs

[Phil Rose]

At 11:32 AM -0500 2/8/01, Glen Powell wrote:
>As the seal between the spark-plug and the head is made by the gasket-washer
>way up they-ahh at the top of the threads, the threads themselves are
>exposed to combustion-chamber by-products and some gunk in the threads is
>normal and to be expected.
>

Tom's post also described the gunk extending on to the insulator. 
It's been my experience that the plugs in the 3B head--even after 
cleaning and installation with proper torquing--will often become 
loose within limited amounts of driving (i.e. under 10K miles). There 
was a thread about this a few years ago on the qlist, in which it was 
concluded that the fineness of the threads (and, ultimately some 
"gunk") prevented any significant loss of compression. But it is a 
little disconcerting.

Phil
-- 

Phil Rose
Rochester, NY
mailto:pjrose at frontiernet.net