You're fine. Unless you try to crank the car up, none of the wires are live when you're changing the plugs. I did mine with the battery hooked up, car didn't explode.

Usually you'd only have to disconnect the battery if you're dealing with fuel or something that is always powered.

 

Great job on the DIY. It was really informative and made everything really simple.

I will say though, be careful when tightening the bolts to the coils. I went too fast and ended up cross threading the last one. It was on the 6 (I believe) cylinder, closet to driver side firewall. Long story short, I couldn't reach the bolt in a manner to apply any real torque so I had to pull the plenum and remove the valve covers. I ended up drilling enough of the bolt out, but couldn't get through the whole thing for some reason. Its like the bottom half of the bolt was titanium or something. Anyway, cut another bolt in half and had enough thread to tighten the last coil. I figure it wasn't a great concern anyway since it just needs to keep the coil from coming loose. Made a 1 hour job into several annoying hours.

Other than that, super easy and great write up!

 

Great post. I recently changed my plugs at the 105k mark on my 05 g35 sedan. I went with the factory NGK dbl platinum. Should I run seafoam through my fuel system on followed by Lucus fuel system treatment or not?

 

Thanks OP!
Did my plugs last night 06 6MT (driven spiritedly ) 88K miles and to my great surprise NO OIL ON PLUGS!!!!! Woot-Woot!!!...plugs where definitely needing replacing after I saw them

It wasn't as PITA as I anticipated (done a few plugs before on other cars), that being said it was not cake either.
Definitely need to be patient when removing coils and plugs. Plugs where tight as fvck and so where the coil bolts. The cables around the coils where a bitch to move around but with some "will" and power knuckles, you'll get them out the way to get the coils.
I threw a SES and it was I forgot to reconnect the Intake air sensor cable to the plenum (dumb ***).

Other than that, she's running great and idling great too. Mind you she was running great before too.


Once again thanks for the DIY!!!

 

Hey guys I just have a quick question. What's the average time for changing the spark plugs on the G35??

Me and my buddy did ours last night and we started at 6:30pm and finished at around 4am....

I'm not too sure why it took us so long because we were going at a good pace with literally no breaks at all. That will be the last time we'll be changing the spark plugs on these cars, next time we're just gonna take it to the shop.

 

In my car's current state, about 15 minutes.

 

I did the install by myself on the G35 and it came out very smooth. I ran into 1 snag which was torquing cylinder 1 too much on the coil pack and snapped the head on the bolt. I was easily able to back it out using a pick tool and my fingers. Including running to the store to get a replacement bolt and couple breaks. I think I was about 3 hours deep into the job. If I had to go back and do it a second time it would take no more than 2 hours with no breaks. It really was not that hard if you have the correct tools and remove the intake / engine cover

 

heh we didn't even buy a torque wrench just because the guy at the auto store said "don't even bother you don't need it" the day I went shopping for a torque wrench. Jeez good thing we didn't break anything or we would've been there all day AND night. Also it's not like we're weak either, me and my buddy go to the gym religiously lol. Oh well it was a really unpleasant and frustrating experience for us I don't think we'll ever want to go through that again.

 

Sorry to hear it took you boys so long man. I did it myself a weeknight after work. Started at around 8pm done by 10pm. No breaks and took my sweet time on each coil pack whether removing them or putting them back on, I did it very very carefully. My back was killing me though!!! Bending over the fender for that long was the most annoying time...my only breaks were standing straight for a few minutes after each plug to give my back a rest.
Regardless I'm having a hard time wrapping my head around what held you guys back so much?
Anyhow, I will definitely do it myself again and I don't expect to take me any more than 1.5hrs max now that I have done it once.

 

hahaha actually YES, our backs were killing us very much too!! 2 days prior to doing spark plugs was back day at the gym and the dead lifts are still hurting my lower back right now lol.

I'm actually still at work right now I woke up Sunday morning at 7am and still haven't slept yet. Although I did take a nap earlier (while at work) and I'm not even joking you I had a nightmare about spark plugs. It was so scary I can't even take another nap and I'm here at my desk dozing off while people are walking by lol.

 

It took me about 2 hrs to do all 6, how did it took you that long? lol

 

I have no idea man, like I'm thinking about it over and over if we took any long breaks but no. What really slowed us down was the lack of extension we had on the ratchet also the damn wires that we had to manouver around.

I even told my buddy that people on G35 driver average between an hour to 2 hour spark plug changes and he finds that hard to believe.

Maybe we're just slightly retarded and work at an extremely slow pace and not even realize it lol

 

Well its 2 hrs for me the second time doing it, the first time it took me 3.5 hrs, but ya if u don't have right extensions or what ever, it can be a PITA.

 

Yea you're right it was a PITA without the right extensions, we actually called up a few friends during the spark plug change to see if they had any extensions and 1 of them came by but was useless.

Here's a pic:



It was 2 cars that took us that long not 1, just in case you guys are wondering haha

 

ahhhhhhhh....i figured out the problem. Your Ontario plates explain it all. You are Canadian and had a bunch of Canadians help you out. I am guessing you are from Mississauga.