another 350!

bugjuice · Post by **bugjuice** » Tue Sep 10, 2013 10:57 am

Just thought I'd come say a quick hi..
Was searching around the net for information on what's ailing my 350 and hoping not for the worst (blown head gasket), and stumbled across here. I like hanging around people with the same interests and I used to be big on the motorbike scene, but since I don't have a bike at the mo, and that forum pissed me off a bit, I've left and feel a bit out of touch now. So nice to find a place about these pretty cool cars. I love 'em anyways!

Mine is a blue track version which is the exact one I wanted in colour, and manual, and the Brems to stop. Great car! Was all stock until last weekend when I fitted a new Kinetix Plenum, had a bad misfire, so replaced the plugs with decent ones (bout due anyway) and new Yellow Jacket coils. Got on the motorway last night and put the boot down and mmmmmm nice white smoke pouring out the back.. so it's parked for the moment until i pull the plugs out again tonight and see if there's a story there.. Anyone know any good mechanics that won't rape the charges for a head gasket or two..?

B101 · Post by **B101** » Tue Sep 10, 2013 11:24 am

welcome to the forum Bugjuice, youl find that the guys on this forum are more than willing to help out where ever they can.

Im sure one of the guys will listen in and give there 2c and hopefully point you in the right direction

BRONZEE · Post by **BRONZEE** » Tue Sep 10, 2013 12:24 pm

bugjuice wrote:Just thought I'd come say a quick hi..
Was searching around the net for information on what's ailing my 350 and hoping not for the worst (blown head gasket), and stumbled across here. I like hanging around people with the same interests and I used to be big on the motorbike scene, but since I don't have a bike at the mo, and that forum pissed me off a bit, I've left and feel a bit out of touch now. So nice to find a place about these pretty cool cars. I love 'em anyways!

Mine is a blue track version which is the exact one I wanted in colour, and manual, and the Brems to stop. Great car! Was all stock until last weekend when I fitted a new Kinetix Plenum, had a bad misfire, so replaced the plugs with decent ones (bout due anyway) and new Yellow Jacket coils. Got on the motorway last night and put the boot down and mmmmmm nice white smoke pouring out the back.. so it's parked for the moment until i pull the plugs out again tonight and see if there's a story there.. Anyone know any good mechanics that won't rape the charges for a head gasket or two..?

Welcome to the forum. Firstly love the username, lol, bugjuice, definitely what Zeds tend to accumulate.

When I read your second sentence, first thought, might have been fan motors. Has it been running hot at all?
Were the plugs clean when you pulled them out, no oil on them? 4/5 tend to be the worst ones. Valve seats can diminish over time.

BRONZEE · Post by **BRONZEE** » Tue Sep 10, 2013 12:26 pm

ps, you should join us for the tech night tomorrow night.

http://zclub.org.nz/viewtopic.php?t=360 ... 4e90fdac04

bugjuice · Post by **bugjuice** » Tue Sep 10, 2013 1:55 pm

BRONZEE wrote:Welcome to the forum. Firstly love the username, lol, bugjuice, definitely what Zeds tend to accumulate.

When I read your second sentence, first thought, might have been fan motors. Has it been running hot at all?
Were the plugs clean when you pulled them out, no oil on them? 4/5 tend to be the worst ones. Valve seats can diminish over time.

Thanks

Nope, the motor was running stable, always has done until a couple of weeks ago when a misfire happened. The CEL came on, I double checked it was a misfire, then ordered new plugs. The misfire went away but then came back a couple of times after the car restarted when warm. Something told me one of the coils might be bad, so I bought new ones. Finally put them in on Sunday just gone. The old plugs that came out, the front two were fairly normal in wear for their age (unknown really!), but the middle 2 were heavier in soot deposits, one had high heat damage actually, thinking back to it. The back two had a lot of soot and more temp, but were both even. hmmm that's got me thinking about that one plug now. Anyways, new plugs went in, I've done about 30kms on them, so I'll pull them back out and see what the story is. It's bad timing that I changed the plenum at the same time, cos everyone is blaming my shoddy work, when it's got nothing to do with it!!

Thanks about tomorrow night too. It's actually not far at all from me. If I can change things tomorrow, then I'll be the new face out the back

As for the user name, it came from when I was riding around the bikes. i was always the one who'd end up with the most bugs on. I've noticed I seem to collect the same amount with the Z now, so I thought it was equally fitting!!

BRONZEE · Post by **BRONZEE** » Tue Sep 10, 2013 2:54 pm

bugjuice wrote:Thanks about tomorrow night too. It's actually not far at all from me. If I can change things tomorrow, then I'll be the new face out the back

As for the user name, it came from when I was riding around the bikes. i was always the one who'd end up with the most bugs on. I've noticed I seem to collect the same amount with the Z now, so I thought it was equally fitting!!

Cool, just flick a post up on the thread, so we can keep track of numbers.

Always good to have newbies along to events.

Fairly flat nose, as you've pointed out certainly attracts bugs, bug mortuary.

OMSIN · Post by **OMSIN** » Tue Sep 10, 2013 5:12 pm

I had replaced my spark plugs when I got my car and also found a bit of a misfire afterwards, turns out I had plugged the airflow meter back in when I did a quick start up test. After putting it all back together It still didn't seem quite right?? Had to do a reset to clear the CEL. Problem with these engines is the wiring looms are all pretty tight around the coils on 4,5,6? Could potentially have pulled a wire out or broken it somewhere under the insulation?? I'm not sure if its my imagination or not but my car hasn't been running as smooth and sharp on the throttle since.

I did a bit of searching when I was looking at an aftermarket plenum, a lot of people are saying bad things about the kinetix saying it actually loses power and just adds noise? how are you finding it? I'm going to get a Motordyne plenum and spacer eventually.

BRONZEE · Post by **BRONZEE** » Tue Sep 10, 2013 6:30 pm

You could try the "pedal dance" that should produce a fault code. You have to get your timing bang on time, to manually produce the cell flash.

http://www.zclub.org.nz/viewtopic.php?t ... edal+dance

bugjuice · Post by **bugjuice** » Tue Sep 10, 2013 10:34 pm

BRONZEE wrote:You could try the "pedal dance" that should produce a fault code. You have to get your timing bang on time, to manually produce the cell flash.

lol pedal dance.. Yeah, I did the dance and got the misfire and knock code out of it which I was expecting. I've tried doing it a second time to reset the light now the plugs have been done, but I can't get it to happen again to clear the code.

I pulled everything apart again tonight and found that the front passenger side plug was kinda oily, the others were fine. One of the plugs on the drivers side wasn't that tight at all either. So cleaned things up a bit, double checked everything and put everything back in. Started it up and ticked over fine. Took it round the block and again, puffs of the white stuff. Smells stupid rich tho, and forgot to mention on the drive yesterday, it drunk a crap load of fuel. So now I'm wondering if it's more the ECU at fault, needs a retune so that it fires right..? and the gasket isn't as bad as I thought (altho still needs to eventually be done!)..

Could a bad tune make things this rough? And yeah, it is tight along the drivers side, but I made a point of not stressing any wires out. Really didn't want to cause another problem!

As for the Kinetix plenum, I've not driven it to know how it goes! Does make a lot more noise tho! Put the pod filter on tonight too, and man, it sounds pretty damn mean now! Can't wait to get the exhaust done! But yeah, kinda makes me wonder about the tune now..

OMSIN · Post by **OMSIN** » Wed Sep 11, 2013 6:25 am

I had a 350 that had oil leaking into the spark plugs, was told by Nissan that the rocker cover seals needed replacing? oil was very noticeable on 2 spark plugs / coils.

Also the moment you start making changes like the plenum the original tune from factory won't necessarily be ideal anymore

BRONZEE · Post by **BRONZEE** » Wed Sep 11, 2013 7:19 am

If I were I would get that car in to be looked at either by City Nissan Takapuna or Scholfields Newmarket.

As OMSIN points out, mods usually effect the efficiency of the car. Backwards step.

bugjuice · Post by **bugjuice** » Wed Sep 11, 2013 4:08 pm

OMSIN wrote:I had a 350 that had oil leaking into the spark plugs, was told by Nissan that the rocker cover seals needed replacing? oil was very noticeable on 2 spark plugs / coils.

Also the moment you start making changes like the plenum the original tune from factory won't necessarily be ideal anymore

Did you have the rocker gaskets done? If you did, how much..?? Guessing it's cheaper than the 4k mark that keeps coming up!!

Had more of a revelation; from the amount of fuel being dumped, and the oddness that it could be something to do with a vacuum line (or pressure) that might be playing up, plus, also like you say, the tune might be so far out of whack now, that the stock ECU map can't compensate any more. So it's booked in with Torque Performance on Monday morning to get a pressure test on the mota and see what's being put out. Fingers crossed it's just a crook pipe line!! Then I can talk to them about a tune up (or if anyone has a highly recommended place)..

OMSIN · Post by **OMSIN** » Wed Sep 11, 2013 5:41 pm

I can't remember exactly what it cost as I got the quote from Nissan and passed it on to the car dealer to fix as it was under warranty, the seal itself is cheap, its the labour to replace them that adds up, would have been in the $100 - 300 range I think. Both driver and passenger side should be done, car dealer only did one side and then a few days later the other one starting leaking as well. Long story short I no longer have that car

Knock sensors tend to fail if the car isn't run on 98 octane I'm told, especially if your using 91 as opposed to the next best option of 95?? not sure how true this claim this.

Oxygen sensors fail when too much carbon builds up on them, My skyline killed many of them when the car started misfiring from bad coils. Should be able to scope them and see if they are reading correctly, they influence how rich the air/fuel ratio is.

How is your pod filter attached? still using factory piping with vacuum lines etc?

My guess is your ecu is reading a high volume of oxygen and is compensating with too much fuel... Cars also tend to run rich to protect the engine in the even it thinks something is wrong. higher fuel ratio = colder combustion (not all of it will burn) = rich smell out exhaust

BRONZEE · Post by **BRONZEE** » Wed Sep 11, 2013 8:34 pm

OMSIN wrote:Knock sensors tend to fail if the car isn't run on 98 octane I'm told, especially if your using 91 as opposed to the next best option of 95?? not sure how true this claim this.

Few 350 DE owners on here, that have purchased pre-loved 350's and had to replace the knock sensors. Well documented in the UK and US.

bugjuice · Post by **bugjuice** » Fri Sep 13, 2013 3:47 pm

OMSIN wrote:I can't remember exactly what it cost as I got the quote from Nissan and passed it on to the car dealer to fix as it was under warranty, the seal itself is cheap, its the labour to replace them that adds up, would have been in the $100 - 300 range I think. Both driver and passenger side should be done, car dealer only did one side and then a few days later the other one starting leaking as well. Long story short I no longer have that car

Knock sensors tend to fail if the car isn't run on 98 octane I'm told, especially if your using 91 as opposed to the next best option of 95?? not sure how true this claim this.

Oxygen sensors fail when too much carbon builds up on them, My skyline killed many of them when the car started misfiring from bad coils. Should be able to scope them and see if they are reading correctly, they influence how rich the air/fuel ratio is.

How is your pod filter attached? still using factory piping with vacuum lines etc?

My guess is your ecu is reading a high volume of oxygen and is compensating with too much fuel... Cars also tend to run rich to protect the engine in the even it thinks something is wrong. higher fuel ratio = colder combustion (not all of it will burn) = rich smell out exhaust

Yeah, well another reason I wanted to replace the coils. Also found a few people imply that they just replace the faulty one.. errrrrr... they all wear the same, they'll all go..?? Anyways, done, and happy with that and the choice..

And regards to the fuel, I've always chucked 95 minimum in there. If it's a good day, then 98, but never ever 91. Just wouldn't. I did run Gull's 98 bio fuel, did a tank and a bit on that down to Taupo n back (computer estimated about 950kms in the tank for that run!!!). Ran fine on the way down, and the way back, then a couple of days later the misfire and knocks came around. I don't know if that's just coincidence, but I feel that the bio stuff is the cause of my issues, so don't think I'll be using that again!

The pod filter is attached to the AFM via adapter mount, the stock tube up to the stock throttle body, then the Kinetix plenum. I just think there's a crap load of air that it doesn't know what to do with. I drove it again last night (faaark it sounds good now!), and it's 'pinking' and jumping around like a kid with ADD, just restless. Then light to medium pressure stutters, then gets about 2,500rpm and runs smooth as. Med+ throttle just bogs it down a bit, and the white steam/fuel/ghost thing comes out again. I think it's a mixture/tune thing and possibly a damaged/not happy vacuum/pressure line somewhere. Once those two bits are done, then I think that should be good to go. Just preying the gaskets aren't as bad as I'm thinking! 4k for a head job..?? I saw an adapter plate on Trademe for the V8 to 350z gearbox for sale.. that got me thinking!