2008 g37s compression test and spark plug question
09-29-2018, 12:35 PM
#1
Registered Member
Thread Starter
2008 g37s compression test and spark plug question
so I have a 2008 g37s coupe
125000 miles
this car I bought used couple years back and has raised questions on what was done previously to the car
I got the car around 60k and now it’s way over due on spark plugs
is it possible for old spark plugs gaps move over time?
i got anywhere from .034 - .056 on the old ones and they were really really old lol wtf
supposed to be at .044 (.043 nismo 370z apparently)
so I did a compression test and got 225 - 230 psi with the motor cold and was wondering if that was too high!?!?
Note i had my throttle bodies out
btw searching for fuel pump relay sucks or I suck at searching so this might help some
it’s the first 15a fuse for fuse pump
and the fuse box is next to the battery
remove pass side windshield cowl
remove battery(just do it)
push two top tabs on the fuse box and lift entire fuse box up(just do it you’ll save time instead of fighting it)
thanks in advance!
then you can reach the bottom tabs to open the box
detach the entire fuse box by pulling the box up and holding tabs,
125000 miles
this car I bought used couple years back and has raised questions on what was done previously to the car
I got the car around 60k and now it’s way over due on spark plugs
is it possible for old spark plugs gaps move over time?
i got anywhere from .034 - .056 on the old ones and they were really really old lol wtf
supposed to be at .044 (.043 nismo 370z apparently)
so I did a compression test and got 225 - 230 psi with the motor cold and was wondering if that was too high!?!?
Note i had my throttle bodies out
btw searching for fuel pump relay sucks or I suck at searching so this might help some
it’s the first 15a fuse for fuse pump
and the fuse box is next to the battery
remove pass side windshield cowl
remove battery(just do it)
push two top tabs on the fuse box and lift entire fuse box up(just do it you’ll save time instead of fighting it)
thanks in advance!
then you can reach the bottom tabs to open the box
detach the entire fuse box by pulling the box up and holding tabs,
07-21-2019, 04:46 PM
#2
It’s not really the gap in the sense of adjusting the ground electrode that increases, the center electrode erodes away overtime as it’s used, causing the space between the ground and center electrode to widen.
And you don’t really do a compression test on a cold engine, I mean you can and if you’re readings are similar then it’s alright but when it’s cold the metal doesn’t expand like it does under operating temperature and therefore less sealing in the combustion chamber. Not sure how you’re getting that high of PSI? I’d question your compression gauge tester.
And you don’t really do a compression test on a cold engine, I mean you can and if you’re readings are similar then it’s alright but when it’s cold the metal doesn’t expand like it does under operating temperature and therefore less sealing in the combustion chamber. Not sure how you’re getting that high of PSI? I’d question your compression gauge tester.
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