Last week after idling for a few minutes I started to get a REALLY rough idle and major loss of power. Took it up to my local shop for a quick scan and got a P0301 code. After restarting the car it ran fine for a few days and then while driving the other day it went from fine to Blinking service engine soon light and same major loss in power, rough running.

Took it to my mechanic last Saturday and when I started it, it was running really rough and I was getting worried about even getting it to the dealer. Thankfully about half way there it started running ok again for the rest of the ride. Interestingly, the service engine soon light would stay on, but it would blink when the misfire was actually taking place.

So my mechanic, who is the GTR mechanic at our local Nissan dealer, diagnosed a few things: 1) clogged and corroded crankcase breather line, 2) coil packs needing replacement, 3) lots of oil on the cylinder 6 plug and some oil on other plugs. He replaced the breather tube and all 6 coilpacks (not sure if all 6 NEEDED replacement, but he knows I do things thoroughly and thought it best to just do all 6--I'll ask him when I pick it up if they were bad or just better to do all at once since others were likely to go. He said the coilpacks going bad are much more common than injectors--injectors in his experience were very, very rare to go bad in the Zs.

I had replaced the valve covers around 100k miles and at that time the cylinder 6 plug did not look like it did yesterday--back then the plugs were actually fairly clean and uniform--back then I burned 1qt of oil every 2500 miles for 125000 miles, but from 125000-150000 miles I was burning 1qt every 1000 miles-my guess is that cylinder 6 is where most of this oil is going.

So, I haven't picked up the car yet but will ask him a few questions and report back when I do. I'll be asking: 1) could the clogged crankcase ventilator tube have anything to do with causing the increased oil consumption and/or cylinder 6 increased oil on the plug, 2)whether all six coils needed replacing, 3)if the PCV valve is part of the crankcase ventilation tube. He didn't do a compression check because he said it wasn't worth it--engine has 150k miles on it, runs well when it is running, burns oil, so no real need to test compression right now.

Let me know if you have any questions you'd like me to run by him when I pick up my car.

Looking forward to getting her back--I recently had all of the dings and scratches etc taken care of, new tint put on etc, so, she looks almost new. Got an oil change and a new battery for winter. So, all in all she should be good to go for awhile. Going to continue to do a few more cosmetic items in the near future for wear and tear items to continue to march towards looking like new. That way if the engine implodes one day I can at least justify putting a new one in since the body and interior are in really good shape.

Some pics to follow.

 

That's crazy!

 

It could be anything (coil, spark plug, ground or really low compression) my 03 sedan with 155k also burns aloy of oil but its fine check yesterday and not much oil was on cly 6 maybe 3 drops, both valve covers are sweating oil and rear main seal is leaking...literally so many issues but like your mechanic said 150k + miles...gonna run it till it blows just watch ur oil levels every other day last thing you want is a spun bearing

 

Yep, it was the coil pack. He replaced all 6 and put on a new breather hose and she drives just as good as new again.

He didn't think the breather hose could have led to the extra oil consumption, but I'm going to keep an eye on this anyways and see if by chance I go back down to 1qt per 2500 miles consumption.

Funny that I had him change my rear Stillen sway bar from mid stiff to full soft (the front is set to full stiff) and it made a huge difference in the grip from the rear end. At mid stiff I felt like the car still had too much oversteer and lost grip around big sweepers etc. Now the back end doesn't react quite as quick but it feels like there is a lot more grip in the rear.

 

Even if bad sensor the car should turn over atleast.. is the starter good?

 

Who said anything about not turning over???

 

Code p0302 (cylinder #2 misfire) with the same symptoms you listed however upon changing the spark plugs and coils.

what caused it was some bad gas how I treated the sluggishness (stupidly I now know) was with octane booster and fuel stabilizer. After I got all of the gas out I than filled up at shell with premium (as usual).

afterwards...
I'm noticing a growling noise and gasoline smell from the exhaust pipes. Am I missing something in this repair? Are my cats bad?