G37xMN

So yesterday I replaced my spark plugs. Noticed quite a bit of oil in most the spark plug wells. Also, there was like one drop of green (coolant?) I noticed. Figured my valve gasket is leaking and I plan on replacing it, no big deal. I Finish up the spark plugs and fire it up. Instantly runs way different; it’s shaking, sounds different, and I think there was more smoke coming out of the exhaust than normal. It smelled terrible like fireworks or an electrical fire. Tried doing some google searches, and nothing really came up. I did not mix up the coil packs as I did them one at a time to prevent this. I don’t think the plugs were too loose, as I snugged them down and gave them an extra 1/4 of a turn. Someone suggested it could be the oil leaked into the cylinder but I figure that would smell like burnt oil not fireworks.

G37xMN

Also forgot to mention I replaced them with the ruthenium plugs off rockauto.

ILM-NC G37S

iTrader: (3)

These engines DO NOT like aftermarket or non-OEM spark plugs. This is a well known fact. Any oil that might have entered the cylinder would have burned off relatively quickly. I doubt that is your issue.

How was the engine running before you installed the new plugs? I would suggest putting your old ones back in and see how the engine runs.

I would also return the Rockauto crap (if you can) and get a set of OEM's. Just my 10¢.

G37xMN

I tossed the old ones when I installed the new ones because I did the job at my dads shop and didn’t wanna leave my garbage there. It was running pretty well other than sometimes it dies right after I start it.. a check engine code was thrown for a map sensor once when it was really cold and it died, then almost died again after startup. Figured that was due to my throttle bodies being dirty (upon doing my spark plugs, they are) and maybe a dirty map sensor. One of my buddy’s who went to school for mechanics is coming to look at it at some point today but wanted some extra insight going into it. If he doesn’t see anything wrong I’ll suggest ordering the OEM Denso’s.

ILM-NC G37S

iTrader: (3)

Never throw away old parts until you are sure all is well. Not trying to beat you up about it, it is just part of the learning curve. We've all been there...

99% of the time when these engine stall at startup it is due to dirty throttle bodies. Sometimes dirty MAF's and MAP's as well, but typically it is the throttle bodies to blame.

Did you at least check to make sure the gap was set correctly on the new plugs?

If you have a code reader you can check to see if any codes are being thrown. That might help us narrow down the issue, but I have a feeling that until you are able to get a set of OEM plugs I doubt she will run smooth.

G37xMN

No I didn’t check the gap because they’re pre gapped at .044 and had a little cardboard cylinder to prevent the end of the spark plug to touch anything during shipping. And yeah I know now to not throw **** away. Gotta learn somehow right? They might still be in the trash can lol, do you think I could just take em out, clean em off and throw em back in?

G37xMN

And yeah I figured the throttle bodies were to blame. Maybe the map sensor(s) need cleaned as well though because that’s what threw a code.

ILM-NC G37S

iTrader: (3)

Just because they are "pre-gapped" does not mean that the gap is correct. Technically, OEM plugs are gapped to .043- though I doubt that extra thousandth will make a difference.
As long as the ceramic insulators are intact, yes. Just make sure the electrode end is entirely clean/free from debris before you install them into the cylinders.
We have all been there and made some bad calls of our own. We are all here to help.

JSolo

iTrader: (14)

Another thought... One or more coil packs gone bad after being manipulated/disturbed during plug R&R?

ILM-NC G37S

iTrader: (3)

I thought the same thing except I am not one for coincidences. If OP is able to salvage his old plugs- and the issues persist- then we can troubleshoot further up the line.

stealthee

I hate the "pregapped" crap. It makes people even more lazy. I have bought "pregapped" plugs before and when I checked them they were all over the place. They were supposed to be pregapped to .039. In the 6 I bought they ranged from .034 to .045. Always, always, always check the gap.

JSolo

iTrader: (14)

Agreed. Best to introduce least variables as possible when troubleshooting.

ILM-NC G37S

iTrader: (3)

In the manner and voice of Oswald Laurence at London's Embankment Station: "Mind. The Gap!"

ngolbuff

Even if you return the ones you bought to Rockauto, they do have the correct ones that are very close to OEM. I got my replacement sparks from Rockauto and they have worked great. I also cleaned the throttle bodies at the same time since they were off

G37xMN

Yep I’ve cleaned the throttle bodies, bought OEM plugs from oreilleys and checked gap on the plugs that were in. Most of them were about .024, new ones were mostly at .043 or .033. Adjusted the ones that were far off and she runs better than ever. Thank you all for your responses.