Joined: Sep 2018

Posts: 66

Likes: 24

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!?!? Possible oil or coolant?
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)
then you can reach the bottom tabs to open the box
detach the entire fuse box by pulling the box up and holding tabs,

Thanks in advance

Joined: Oct 2014

Posts: 6,105

Likes: 842

From: Houston, Tx

Your compression numbers are good.

Spark gaps change over time as the electrodes slowly erode in the hellfire that is combustion. Unless you measured them new, you have no idea what the original gaps were.

Joined: Sep 2018

Posts: 66

Likes: 24

thanks for the help!! But gaps that bad?!?

Joined: Oct 2014

Posts: 6,105

Likes: 842

From: Houston, Tx

As I wrote, you have no idea what the original gaps were. They could have started that badly.