I've searched but didn't find the answer.
I have a 05' G35 Coupe with 173k miles on the coil packs. The motor is newer but used the old Coil Packs. I have a studder around 4500-5000 rpms and the car is not as strong as it used to be. The only OLD parts with 173k are the Cam position sensor on the passenger side and the coil packs.

I am having issues with my Navigator Coil Packs at 133k, so it made me thing about the G.
My gas mileage has gone down about 2 mpg and it doesn't have the same power it used to. I think it might be time to replace the coil packs. No Codes but neither did my Navigator but the Coil packs made a HUGE difference in the power and mpg. I think the Coil packs are weak.

Who knows what the lifespan is on a coil pack?

WHat's your thoughts on my situation here?

 

You could take one of your coil packs off and have it tested but my advice is to leave it alone. If she's still running with that kinda mileage changing anything might cause something else to fail....if it's not broken, don't fix it!
Gary

 

That's just it. It's got the stumble and the idle is not smooth like it once was. Pretty much, the coils are the only thing that is old on the motor. Everything is new

 

If a coil pack was bad there would be a misfire which would cause a very noticeable vibration. A misfire would pop a code too. Unless your engine is vibrating the car a lot more then it should be, chances are the coil packs are still working.

 

Take it to a qualified Nissan mechanic (not the dealership) and find out where the stumble is coming from. Could be a plug wire, replacing all the coil packs may not fix the problem unless it's tested....Gary

 

Usually I would agree until I had the experience with my Navigator last week where it showed #3 cylinder misfire in the Code. P0303. I replaced the coil pack and took it for a test drive. It acted up again and threw a P0301. I switched the #1 for the #5 and it got better and then got worse again but didn't throw a CEL. I drove it for the day that way and it continued to spudder under acceleration until I changed all the coil packs and now it runs good, idles smooth again and I can now spin the tires on that big ol' Gator.

I have a normal Code scanner, but without the expensive computer scanner that reads all the different algorythms etc, you can't tell if you have a weak, but not failing coil pack.

I just figured I would ask on the board to see if the symptoms have happened before. It seems that The coil packs that Nissan make are long lasting but with 173k miles I am thinking I am pushing them, especially when doing a hard pull from a stop sign and it stumbles accelerating.

 

It popped a code for me when #6 randomly misfired and I'm fairly certain it will always pop a code for that situation. The whole front end vibrated when it happened too. My pack never went bad though, it was just loose. I wouldn't base your diagnosis off an entirely different vehicle either.

 

True.

 

Coming upon 200k miles, is about time for the plugs to be changed again.

 

I have 42k on my motor. I had to change it at 131k cause the hamonic balancer came off for no apparent reason one day during me jumping across the road and spun the crank separate from the valves and ruined EVERY valve.
https://g35driver.com/forums/g35-cou...ain-broke.html

I originally thought the timing chain had broke. I soon found out different when I dug into it.

 

I researched coil pack issues a while back on my g and from what I've read the coil packs either work or don't there's really no in between. If one didn't it would cause a misfire and throw a code. Ian's just remember just because everything else on the motor is new doesn't mean that It was installed correctly or in perfect working order

 

Yes, you are prolly correct. I'll keep looking