30w is very light oil. Id expect a modern engine in good tune with low km.

As for 'blowing off', short of something flamable, being ignited by an arc...(cracked lead/boot - run it in a dark garage and watch for fireworks)
it would have to be mechanical or blow by gas. Check compression on that cyl. Check lead isnt getting caught by fan/pulley etc.

 

30w light oil??? like seriously..... thats why cars use mainly 5w and 10w... because 5w is really thick right...... wrong..... who ever thinks 30w is light oil should be shot.... point blank

 

bad day at the office honey?

5w oil is basically diesel.

 

Im sorry you didnt do your home work first before you opened your mouth...... Most newer cars call for 5w 30 oil....... It is especially good for colder climates... For warmer climates i would not exceed 10w 30 oil... Ive ran 20w oil in cars before but its much too thick when it gets cold out so i doubt 30w is gonna be nice and light and thin.... Juss sayin... It will be more like honey when cold

 

no i dont believe they make any such thing as 30w-5.... im guessing he is referring to straight up 30w oil... im sorry but thats too thick for todays cars and all the highly tight tolerances etc..... maybe back in the really old days that type of oil would have been acceptable but not now.... i mean who in the right mind would use a non detergent oil in their engine unless you want issues.... now i admit that 30w would be just fine in a 365 day hot climate but never should it be used in colder climates... honestly if car makers thought it was good suitable oil, they would run it in their cars... instead you see multi grade viscosity oils used...there is a reason for this

 

my point exactly. except i use 20w 50. and 5w30 is a diesel oil AFAIC.
but, different strokes for different folks, and climes. i drive from sea level to 200m above, temperature fluctuates from 0 to 25 and i drive a 20 year old large displacement 4 cyl.

the OP is using 30w (single grade) full synthetic.
to me, and as i said, it'd have to be a newer engine in good order.

no need for anyone to get their panties in a twist, which someone obviously has, so sorry for twisting your panties, anonymous complainer.

but this thread wasn't about oil, and no-one else has contributed anything positive to help the OP, so back on track eh chaps?

 

Akzle, thanks for your reply.


It doesn't really "blow off" as much as slowly builds up pressure under the boot cap and then "pops off." Keep in mind, the top of the boot has a collar that seals the tube from any debris. If pressure were to build up in the tube (as mine is), somehow, it would eventually push up, on that collar, eventually leading to it's unseating to release the pressure.
If I reseat the plug boot properly and drive for about 10-15 minutes, when I shut off the engine and then pull the boot off, it does have the feeling and sound of a little pressure releasing.
The thing is, even with the boot unseated and kinda flopping around the tube the spark still makes it to the plug head and the engine runs normally.