ZJoe

iTrader: (8)

Yes, I used the search feature and found nothing. This means that either no one really documented this issue properly hence the difficulty in finding the information or I am the only one that has messed up like this, making me a goofy bastard f**ktard that doesn't know what he's doing. The truth of which will be revealed shortly.

I did the valve cover replacement dealio due to my #6 spark plug cylinder being filled with oil (about 50%). I don't care what anyone says, this is a royal PIA. Anyway, I went ahead and replaced all my plugs with the NGK replacements (NGK 6240's). One (#6) was covered in oil obviously, the others were dark and old as expected for a car with 83K miles.

I also cleaned and recharged my JTW intake filter (cone style) and applied a new coat of filter oil over it.

So after putting it all back together I fired her up and the car started easily. BUT it idled a bit rough and I gave it about 30 seconds to settle down then I noticed copious amounts of white smoke billowing from the tail pipes. Umm, right. So I shut her down and reinspected everything.

So it turns out I forgot to hook up three hoses. The passenger side valve cover vacuum hose, and two hoses behind the upper plenum. I hooked them all up and fired her up again. VERY smooth idle and the throttle was nice and responsive. Waited a minute and a small amount of white smoke started creeping out of the exhaust then it picked up and got worse, not however as bad as the first time I started it. The smoke does not smell like motor oil (and it's not blue), hangs in the air quite like a fog and is thick, and has a smell that is not quite sweet and smells a bit like the filter oil (kinda).

So, here is my theory.

A.) Some of the oil from my JWT air filter got sucked in and is burning off. Continuing to let the engine run will eventually burn off the remaining residual oil. Seems like a lot of smoke for something like this though.

B.) Because of the hoses being unplugged some coolant was sucked into the engine. Continuing to let the engine run will eventually burn off the remaining residual coolant.

C.) The space time continuum allowed for a coincidence of my heads falling apart at the exact moment that I finished the VC replacement and my engine is now fubar. If so, it idles remarkably smooth however.

Any other suggestions of what could be going on, and more importantly, how to remedy this mess, would be GREATLY appreciated.

JERZ350

iTrader: (2)

Although when i did my popcharger and kinetix manifold, I did not get any smoke at all. But on previous cars, whenever i put new aftermarket intakes on, or whenever i did a tune-up, the car did spew white smoke for a few minutes. I even read that it was normal and to expect it.

I could not know wtf im talking about but, yea maybe you over-oiled the filter, or maybe when taking off your hoses is it possible any antifreeze got in somewhere and is burning out?

ZJoe

iTrader: (8)

Thanks for your time responding. I should also add that I've got the Motordyne 1/2" spacer and the Exoticspeed R1 exhaust. Point being, it's not stock and I've opened up the plenum area for the spacer before and I never had this issue.

Yeah, I'm thinking this too. I'm hoping someone that knows can lead me in the right direction on what to do if either of these are the case. It's my daily driver so for the past two days I've been using public transit. To say I need help is an understatement!

winchman

I don't think you need to remove cooling system hoses for changing the valve covers and spark plugs, so you shouldn't have any coolant in the intake.

You would have to remove some hoses for the crankcase ventilation system, though. The engine would run rough if those hoses weren't connected.

I'd blame the white smoke on having put too much oil on the air filter. That'll go away after a while. Maybe you could blot the filter with paper towels to soak up some of the excess oil.

bmccann101

iTrader: (16)

OP, coolant flows to your throttle body i believe.
Many plenums either bypass this or run coolant into themselves.. the thermal plenums etc..

You may be fully running coolant into your engine if you misrouted a hose on the plenum... my guess is that youd surely notice the hose that had antifreeze comming out of it tho.
Just throwing it out there and trying to help because you type crazy sh#t just like me., and i duely approve of this behavior.

Z1 Performance

iTrader: (564)

he probably removed the coolant hoses that connect to the throttle body

ZJoe

iTrader: (8)

This ^ Yeah, I disconnected all hoses running to the upper plenum and of course the air intake tube. There are two others in the back, one that runs down into the block and a third one that I don't know what the hell it does. I'm not an expert engine man but when sh*t makes sense you don't need to be, just like a puzzle. My problem was that I didn't label or take photos of what I needed to label and take photos of. That's me being a f**ktard because I was impatient.

Haha, I've noticed that about you in some of your posts. You provide an entertaining read While I am running the plenum spacer I'm not using the coolant bypass valve that was an option. Didn't see the need and it's run fine for over a year, till now of course.

Last night when I fired her up for the first time I was punch drunk tired from leaning over the car for about 7 hours, after an 8 hour work day. When I saw the smoke I said "f**k it" and went to bed. Being more awake today I'll just go over all the connections again, unplug and replug, look for coolant etc., put it all back together again, and go from there. I'm also going to clean up the air filter and re-oil it but with less oil. I'll update as I learn more.

bmccann101

iTrader: (16)

I do try.

its easy due to the fact im a Fawking incredible charmer in real life.. mom says I'm her special snowflake. bahahah.

good luck on your white smoke tho.. hope it doesnt end up blowing into your cowl vents and you wind up having to drive around like this guy:

ZJoe

iTrader: (8)

Ok, all is well now, mostly. I went back in under the hood and rechecked all my connections and hoses. There is one bolt hole on the driver's side VC that I didn't plug. Oddly, I don't remember that from when I removed the original. I put a bolt in. Anyway, I fired her up and went on a short drive. Nothing. After about five minutes I pulled over and noticed *some* white smoke but extremely light, almost like vapor as there was some condensation on the exhaust tip. I drove around for another short while without incident.

However, it still feels like maybe the #6 plug is fouled out or the coil is bad. I may have to replace that but in the end, the smoking issue is gone. Problelm solved.

ZJoe

iTrader: (8)

Update...

To recap, I changed out the valve covers and put in new spark plugs. #6 spark cylinder was about 50% full of oil. I drained it, cleaned it, and the car seems to be soft below 4000 rpm but strong as normal at 4K and above. I decided to take her in for a leak down test and this is the result.

#1-#5 were at 2.5% loss. #6 was at 4% loss on the piston ring.

The shop that did the test does more work on Hondas but I know they've done work on a lot of Z's. Most of the work they've done on Z's however I think is superficial, limited to maybe some bolt-ons (suspension, plenums, at least one Greddy TT that I know of). They were saying that 4% loss on #6 is pretty bad and that while it doesn't mean the engine will go anytime soon it would be a good idea to shave my backside for when it comes time to bend over and rebuild or swap.

Oddly, the car is running a bit better on the low end now. It started running a bit better right before the leak down test, almost a week after new plugs and the VC was replaced. Anyway, what say you, my 350Z brethren? Is 4% loss on #6 bad when 1-5 is at 2.5%? Car has 83K miles btw.

ZJoe

iTrader: (8)

Anyone? How "bad" is this leak down result with 4% leak on #6 or is it fine? I'd like to put a Vortec on, at 83K miles. Would it be safe to do this?