xenorae

So I was going to change my spark plugs after the z’s started misfiring and ran into a slight problem with the front passenger side coil pack. There’s a very very stiff hose directly on top of the coil pack and I can’t grt it out with the hose in the way. I have no idea what the hose is or if it’s safe to take off and i’d appreciate some advice here

CK_32

iTrader: (1)

Pic?

It's probably just a vacume hose.

xenorae

this lil hose right here; it doesn't seem like it wants to be moved

jv350z

iTrader: (6)

it's the hose on the PCV valve (which is right under where you have circled in red). I had the same issue. The hose seemed to be stuck-tight, even after sliding the clam with pliers. you can try removing the other end of the hose (front of plenum), and then rotating (pivot at the PCV) the hose away from the coil.

dkmura

iTrader: (64)

Before you start swapping plugs, did you check for codes that might indicate WHY the misfire occurred? How many miles are on those spark plugs in the first place?

xenorae

Yeah, I just recently got the car about 3 weeks ago and drove around a hundred miles before it started. The old owner said he never replaced the plugs as long as he’s had it and it’s currently at 170k, so I figured it’s about that time. The code given to me was random misfiring and the knock sensor as well.

samsniss350z

As dkmura says, I'd definitely find out what code is being thrown up and the I'd definitely be buying myself a new set of plugs. Iridium or Platinum plugs can last up to 60,000 miles. So it would be fair to say that your plugs are shot. You could remove the PCV valve, plug the plenum end and put a small wire filter on the head.

Atreyu'z 350

That hose is not that hard to remove. Move the clamp up 3 inches with pliers, then get a flat-head screwdriver and wedge it a little bit between the end of the hose and the PCV valve that it's sliding onto and give the screwdriver a twist to help pry it off while at the same time pulling and working the hose upward with your other hand.

tmdz

If you’re at 170k you may as well replace the valve covers. The Z is kind of notorious for leaking oil from the o-ring seals around the coil pack(s) which will then collect around the spark plug(s). The o-rings are not replaceable, or at least are a giant PITA to replace alone. A set of valve covers can be had on EBay for about $70.

Usually the driver side cylinder closest to the firewall is the worst.

dkmura

iTrader: (64)

Clarification: the OEM NGK Iridium plugs last up to 100K miles!

xenorae

Looking back, I probably should’ve done this in the first place, but I made an appointment with Z1 to inspect the entire car since it’s still fairly new to me and i’ll probably just get them to change the boots and plugs while they’re at it. I’d love to work on my own car but I feel like I don’t know nearly enough about it and i’d rather not mess something up yknow

JCat

iTrader: (4)

Z1 is the best.

dboyzalter

iTrader: (3)

Messing things up is the best way to learn.

xenorae

I’m lucky enough to live like an hour away so may as well since they’re so reputable