Ok so I purchased my 03 track edition with 65k miles on it and after driving it for a while and driving another 03 z, I realized that for some reason my car felt like it had less power so I decided to change spark plugs and put test pipes on incase catalyc converters were clogged.

The catalyc converters turned out to be new so I still installed some test pipes and then moved on to installing a set of new NGK iridiums. I dont think the original spark plugs were ever replaced but what worried me the most is that #6 spark plug had a lot more oil on it than the rest of the plugs. I even saw it drip some oil as I was taking the plug out. Should I be worried about a situation like this? here is a picture of the plugs and also keep in mind that they had 65k miles on them.



Let me know what you guys think, thanks in advance

 

your valve cover is leaking from the coil pack holes. only way to fix is to get new valve covers. some people have had good luck just putting silicone around the holes.

those spark plugs look bad though.

 

Plenty of oil in the combustion chamber. Hey wait oil isn't supposed to be there!

 

if i were you, while getting this looked at, get a compression check done

 

^ thats would just sadden the guy if it came back low compression. I rather not know.

 

Well I think my compression is good because I just did a dyno a coupel weeks ago and results were fine. I put down 235hp and 225 lbs of torque. I consider that pretty good for an 03 with a pop charger and catback exhaust. I still had the shitty sparkplugs in it and the cats when i dynoed.

 

Dude thats exactly the same thing im going thru. Buddy of mine has same car and same mods but his pulls a lot harder than mine. Mine feels like theres some lag under 3k rpm(when i step on it under 3k rpm, i have to wait before i feel any response from the engine???) and even up top it doesn't pull as hard. I just got my codes read and apparently it's a low input knock sensor? I will also look into changing my spark plugs.

BTW did your car feel any different after the spark plugs have been installed?

 

Yes I felt a huge difference when I replaced my spark plugs but what im worried about is the OIL on my damn #6 spark plug.

 

^ cool, ill change mine tomorrow And you may have to change your valve covers like everyone has already said. Good LUCK!

 

Your compression should be fine. Change your valve cover gaskets

 

I also have this problem, 03' Enthusiast model. Low input knock sensor, replaced the knock sensor, code is still there
i haven't driven anyone elses Z but i do suspect i am losing power.

No ideas on what to do about the knock sensor.... anyone?

 

^ Wait so you replaced your knock sensor and you didn't feel a difference? Mine has a low input knock sensor and im hoping thats the reason for my power loss. Id be pretty pissed if it wasnt (since its a PITA to change). Anyway can u describe this "power loss"? Mine is all throughout the power band, but mostly below 3k rpm. Its really annoying.

 

^ I have code P0327 or low input knock sensor. basically means the engine management computer is receiving a weak signal from the knock sensor. The computer may put the engine in failsafe mode which retards your ignition timing, and that is probably where you would feel the loss of power.

I took it in, they replaced the knock sensor and i still got the code. i got pissed cause it probably wasn't the sensor itself and was probably the wire harnesses that connects it to the engine computer. So if you do take it in have them check the wiring harnesses b/c i have been told that knock sensors rarely go bad.

I didn't feel a difference after it was replaced, but i used Cipher to monitor my ignition timing and so far it says my ignition timing is right (15 degrees BTDC). I bought the car used for a good deal. And the only reason I am saying i feel like i am losing power is because it doesn't feel fast. But i haven't driven anyone else's Z so it could all be in my head

So my power loss thing may not be too much help for you cause it could all be in my head. But if you think it is your knock sensor then what could be happening is that your engine management may be retarding ignition timing to avoid knocking. If so, try having the wire harnesses for the k. sensor checked. Feel free to PM me if you have more questions cause i am probably experiencing the same thing as you.

 

Can someone chime in on that ^. I just ordered my knock sensor and it would REALLY suck if that doesn't get rid of my codes. Does anyone know why his didn't go away? How can i tell if my wire harness for the Knock sensor is bad? HELP!

BTW, i just changed my spark plugs, which pretty much were just ash lol and that alone made a HUGE difference in throttle response and smoothness of my revs. It feels like that alone freed up so much power i was missing before. However my car still doesn't feel nearly as fast as my friends Z (same year,same mods etc). Thats where im hoping this knock sensor is the culprit.

 

way to rob my thread are you guys serious. GTFO

 

^ damn dude, i thought we were just here to help each other out? And wat part of change your valve cover dont u understand? It's not normal and yes u should be worried, thats why we told u to do something about it. Good luck, and have fun with your thread.

 

your question has been answered. do you have a problem? yes, change your valve covers. Should you be worried? no.

 

I have a loss of power as well it sucks car fells like its straining i think its the plugs as well and how much is it to change valve cover? or is it just the gaskets?

 

http://www.courtesyparts.com/350z-pa...5_716_720.html



They are about 200 each..

 

Jay you are awesome thanks. i will start with the plugs first. can you point me in direction for where i can pull plugs on my car? also are nissan plugs the best for this? oh and what is reason that valve cover should be changed what is the problem with it? sorry for the questions but i like to just ask and be educated. I also have a 5/16 spacer i never put in yet maybe ill install it as well.