raylomas26

I'll go out on a limb here... How many miles are on your rings and what temperature thermostat are you using?

slay2k

About 21k miles on the stock engine with the stock thermostat. Why ?

raylomas26

Just a thought.

I had an `88 Shadow ES Turbo about 10 years ago. I rebuilt the engine and it smoked bad right from the start. I couldn't figure out what was wrong and neither could my machinist. After a few weeks of this, I got the bright idea to change my thermostat (160) to a stock one. After about an hour of driving, the smoke was noticeably less. Within days it was gone and never smoked again.

The rings would not seat because the engine wasn't getting to its full operating temperature. My machinist said that he saw that happen before with a V8 boat engine, but what happened to me was rare.

I guess in your case this would not apply...

Fall-Line

Mr Romy.
Sell it while you can, and buy that GSX we've been talkin bout.

slay2k

News update:

Started the car this morning (warmer out) to test for smoke. Turned it on, free-rev'd it to 4k, then to 5k... no smoke. Runs fine.

Weird ?

PS, Fall-Line: Die.

Enron Exec

If the compression test and leak down dont show anything, maybe its the turbo bearings? The PCV should only blow a little oil at high revs.

slay2k

There's no oil anywhere around the turbos, wouldn't there be some if the bearings were faulty ?

Daking350z

Not if its leaking right into the down pipe and burning off...Oil would be BLUSish smoke...White smoke is COOLANT which would be a head gasket..your oild would look frothy on the dip stick with coolant present..Do you have cats??Could be bad cats burning up...

slay2k

Hey J,

No bluish smoke. No frothy oil on the dipstick. I don't think it's got anything to do with coolant. And no, I don't have cats... I have straight-thru pipes w/ resonators, so that can't be the issue either.

BTW, I drove the car yesterday and free-rev'd it, and the smoke is back. Very strange eh ? It's there one day, gone the next. WTF is going on.

BriGuyMax

iTrader: (4)

Maybe you guys are looking way too far into this.

It could just be condensation in the exhaust. If it was something wrong with the motor itself it doesn't seem to me like it would come and go as you say it does.

Has the "smoke" ever appeared after an extended drive? (over 30 minutes) because that's plenty of time of any moisture in the exhaust to evaporate.

Daking350z

I dont think it would be condensation with all the things he has described...It definitely isnt NORMAL to blow smoke from your tailpipe.What about an O2 sensor going bad causing unburnt mixture???Possible??

slay2k

Yeah I don't think it's condensation either.

I *have* driven the car for over 30 min, pulled over... and the car still blew smoke. Then the next day it went away completely, and then the next it comes right back just like before.

I don't really know what I should do. I don't have enough funds available to just start building the motor up on the assumption that it's a piston or something of the sort. I simply want to get the issue found and fixed. I don't want a forged engine right now =(

What would you guys do in my shoes?

Daking350z

If compression and leakdown tests were negative then it must be comming from the turbo seals...I would think it was a valve seal but it would do it when you first started the car and it got warm...Free reving is not the best thing to do for your engine in the first place so dont do that..Kind of like that old doctor joke: Doctor it hurts when I do this...So dont do that..
I would have narve check the turbos check the undercarriage for oil and check the O2 sensors if one is bad it could be excess Carbon Monixide gases you are seeing from an unburnt irratic mixture at idle...Check your idel A/F ratios when it does it..

slay2k

I don't think they did a leakdown test.

They looked at the turbos and saw no oil around them anywhere. I'll talk to him about the O2 sensors. I can't measure the A/F right now since I don't have a gauge and their dyno isn't quite ready just yet.

Any other things I should ask/do ?

Daking350z

not really..can onle be one of three things..oil,coolant,fuel...

slay2k

What's a leakdown test exactly ? And what are the chances of this being like Gurgen thinks he had in his engine... a damaged piston/seal/ring/whatever ?

Juztin

iTrader: (9)

You might wanna do a compression/leakdown test elsewhere, and ask for a record of the numbers. Sounds like your getting shady service which is the last thing you need right now with your symptoms.

Daking350z

Theres no way he is getting Shady service..Narvin is an honest dude..If he can not diagnose it then it must have him really baffled...A leakdown test is when they pump compressed air into the ingine and see if there are any blown seals,gaskets and where its comming from...175 sounds a bit low on the compression 190-210 I thought was norm on our engines..I know mikescylinders were all 190 except for the blown one at 85...
could be a valve seat,or ring not sealing 100% getting occasional blowbye...
Only time will tell if it gets worse..You seem to have FI troubles constantly man!!!Get rid of the Z and get an EVO!!

JCat

iTrader: (4)

Stick your (or get a friend to) nose right into the smoke at the exhaust tip. You'll know from the smell if it is oil or coolant. Aslo, hold your hand in front of the exhaust to see if water will condensate on it.

Also, look for:

• smoke coming out of your dipstick hole or pvc hole.
• Bubbles in your coolant with the car running.
• Oil residue in the intake tube.
• Low oil or coolant level.
• Unusual temperature readings.
• Drain your oil and/or your coolant and examine it closely.

Once I saw an engine that smoked only when the rings on a certain piston lined up a certain way. Since the rings rotate around the piston (I'm not sure how much is normal) the car would smoke only when the rings happend to be in a certain alignment.

After or during a "smoking session", pull the plugs and inspect them. Since something IS BURNING you should be able to identify it.

slay2k

Someone posted (Chebosto I believe) that the norm is 185, and as low as 140 is still within range.

With regards to having FI troubles, no sh*t :] Although I did enjoy the PE kit for a whole 2-3 months without any issues, unlike the Greddy. Your Evo comment is funny because I've actually seriously considered that car. If only it didn't look like a pile of dung.

I love the Z, if only I could fix this issue I'd be perfectly set.