Hey Guys

Here is what I posted on my350z:

Hey Guys

Ok...here is the deal.... Got the manifolds fixed Tuesday (they were cracked ... but that's another story) and put in new test pipes (LaBree, resonated) the next morning (wednesday). BTW, the car got considerably quieter with the resonated test pipes compared to the awful RT cats (which by the way were definitely on their way out if not already there).

Ok, here is the problem. If I do a run (full or even partial boost) or just rev the car while at rest (idling in N), then 3-5 seconds later whitish/greyish/blueish smoke begins to come out of the tailpipe. The harder the run, the more smoke is expelled and for a longer period of time. For example, I did a 100-150 yard 1st gear run to about 50-60mph, and coasted for another 1/4 mile, when, as i come to a red light a HUGE plume of smoke just screens the rear of my car. And NO, it never happens during the run, but a while after! That's what's so peculiar.

This had never happened before, and only came to be after my test pipe install the fixing of the manifold.

Needless to say, the first thing we (Clint, THX723) thought was blow by and worn rings! Well, i did a very meticulous compression check this morning, and here are the results (compared to those done exactly 2.5 months ago):


Cyl: Compression (June 16) Compression (TODAY - Sept 2)
1 205 201
2 200 200
3 212 197
4 200 185
5 210 205
6 200 192

The numbers look good. Each time, a different instrument was used (this last one was done with a new comprssion gauge, the first by a mechanic with my participation and oversight).

What do you guys think. I just don't think it can be the rings. It could be the PCV system... but heck there is only one valve there.

Thanks in advance
Gurgen

 

I honestly dont know if it has to do with your engine, but again im not as experienced with engines or FI like you and other people. When i got my borla on and test pipe's my car was smoking same whitish/greyish/blue smoke you are describing, i have a video of it also when other people noticed it. I seriously think its from the test pipe's being worn in, it has a lot of stuff that needs to be burned off ont he inside of the test pipe's, also since your turbo and there are so many gaseous exhausts coming out it makes an even bigger cloud of smoke then a stock NA car, get it checked out but thats what i think it is. Man sry to hear BTW, hope all is well with it. Martin


Martin
2003.5 BS G35
Nismo Aero/Sport Package
0-60 5.4 - 1/4 Mile 14.16 *GTech* and on 19's!!

 

Hey martin

Thanks for the reply... BUt it see,s to be way too dense to be test pipes related.... I was getting honked at on the fwy, after which they would pull up nest to me and yelll "You car is on fire, your car is on fire". Embarassing. It is really THAT much smoke sometimes.

There is oil being burned, that's the only way you could have that smoke. Now, how does the oil get into the combustion chamber and why does it happen only after (a while after) a high-load run? Thats the question.

 

After having driven a turbocharged car for 25 years, I may have a little insight into your smoke. I believe the seal on one or both of your turbocharger bearings is bad. The bearing between the intake and exhaust "fans" is probably supplied with engine oil. The heat from the exhaust side ruins the seals on this bearing. Engine oils leaks into the exhaust system and sits there until increased rpms makes enough heat to burn it off. Oil may also leak into the intake side which makes smoke as well. The cracked exhaust manifolds suggest there was excess heat which may have toasted the turbo bearing seals at the same time. If you can open the dual exhaust system in front of the muffler you can determine which turbo seal is bad. Follow the exhaust smoke back to the bad seal. Are you turbo bearings water cooled? Good luck.

G_Zoom

2004 Sedan 6MT, pearl white - willow

 

PE KING,
I thought white smoke was water,not oil burning
Maybe a blown head gasket,thats all I can think of but you're not constantly smoking so I dont know.
G_Zoom has a good theory with the turbo bearing being cooked,maybe water cooling IS a good Idea.
Either way,keep us all informed.Hopefully it's nothin big.

Blk G35c AT Stillen SC 7lb pulley Stillen valve body Volk LE37's Tein susp. KAAZ Lsd
"throw it in the gutter and go buy another"

 

That's good advice. Thanks

The turbos CAN be watercooled, but the kit does not supply the necessary plumbing. Also, there is a certain way that the watercooling needs to be hooked up, and since I do not know which way taht is, I held off on until i could assemble further info (and di not htink that that would be such a big deal, given that all the 350z/g35 guys but 1 are not water-cooling).

Let me ask a follow up.... You said "Engine oils leaks into the exhaust system and sits there until increased rpms makes enough heat to burn it off". My question. If this is the scenario that is currently in play, would i not have smoke right at the time of the "high rpm/heat/load" operaton, i.e. while I rev the engine and not, at times, as long as a minute after (usually 5 seconds). If so, do you think the oil into the intake side is more likely?

ANother findings: I took the upper plenum off today for inspection. The space under the upper plenum at the top of the intake runners is VERY clean and devoid of almost a drop of oil. So.... It is may be that the oil is not traveling through the intake tube, the compressor side of the turbo, the charge tube, the intercooler, and finally the plenum. Is this a safe assumption? If so... then it must be the oil seals dumping oil onto the exhaust side of the turbo directly. But I would think that you need the oil to be in the combustion chamber to produce such smoke, and not be "merely" heated by the exhaust gases.

Urghh... this is an express ticket to the nuthouse.

Thanks for your input. Do you have a suggestion on the steps that I can take to diagnose the problem?

Gurgen

 

I don't think it's a blown head gasket otherwise his car would be overheating. The bearing theory is a good start to determine the cause of the smoke. White blueish smoke usually indicates burning oil coming from the engine internals. Bad piston ring can cause this Blow By is a bad thing. Maybe a bad valve seal, but this usually happens when you start the engine cold in the morning or if the engine has been off for about 8 hrs. Was your ECU ever tuned by the people who installed the FI on your car. I know one member from Temecula that had and ATI SC on his coupe blew (blow by) his engine within 6 weeks of install. Better start tracing the problem before it's gets any worse. Do some process of elimination to zero in on the problem. Goodluck I hope you find the culprit and fix this problem.



<font color=blue>04 CB COUPE / WILLOW / PREM PACK</font color=blue>

 

Glen

The car was absolutely tuned... and done so very well. In additon, I have the J&S safeguard watching my back the entire time... The a/f has been and is a near ideal 11.8-11.2. Also, in the past 2-3 weeks, I have not run the car over 5-5.5 psi, and literally 99% of the time run with the boost controller OFF (at 4.3-4.7 psi).

This is why it is so perplexing.

Gurgen

 

It suddenly started happening right after you had the manifolds replaced and one of the turbos was taken down, right? Occam's Razor, man.

--Steve

 

Nah, I had a ypipe on my Maxima a while back that wasn't coated. And it smoked so bad that you couldn't even see the tail of the car! It did this for a while, I forget how long. Give it at least 500 miles I would say before it goes away.

2004 Infiniti G35S, 6MT, Premium, Sport, DP
Mods: JDM Clears, 20% tint, Z-tube, Stilen CAI
Track: 14.32 at 98.79 mph 2.2032 60ft
Dyno 07-07-04 - 234.2 hp & 233.8 tq
http://www.g35world.com

 

Like G35_TX thats what i thought it could be also, but if its that much smoke i dont know :/ .. Alot of other people gave you good info, i would take some of each and go have it checked out and basically do a process of elimination. Check the head gaskets, test pipe's and exhuast, turbo bearings and so on. You dont want to wait 500 mile swith your car like that, like i said im not an expert so i cant say anything else lol. Good luck with it though again, sucks to see this happen :/


Martin
2003.5 BS G35
Nismo Aero/Sport Package
0-60 5.4 - 1/4 Mile 14.16 *GTech* and on 19's!!

 

In my past life as an auto mechanic , the symptoms described (at least on an old push rod engine would have indicated a bad intake valve stem seal. The oil gets sucked in mostly upon decel after a hard run. THis si when more oil has been pumped into the valve cover and the stem is "soaked". You would be suprised how little oil it takes to make a huge cloud.

It is possible that the head got hot enough to and cook the vlave seal(s) or the turbo(s) seal a valve seal? Or

Either way it souds as if there is a small oil leak some were in your intake path, hence why it is not noticed during a run , but after.

 

Regarding iLLG35 and G35TX's posts:

If it's the burn off of a new exhaust related part it smells different. That type of smoke has a distinct smell, much different from a burning water or burning oil smell.

Can Grugen relate smells?

04 6MT Sedan - Z Tube, K&N Drop-In, 04 Z Suspension

 

This is exactly what happens when the seals go on the turbo/s. I went through this on both my TT RX7's. I'm not sure what turbos you are running...are they new, or used? Weird since it usually takes time for them to go bad.

 

Zimbo...

Occam's Razor all the way my friend! But I am at a loss at what he can possibly have done by taking the turbo on and off.

Cook..
The turbos are about 4000 miles/2months old. This should NEVER ever have happened this early, even if these were abused big time. THe are PE 1420 turbos have a very good reputation from what I know.

BrianV...
The smell is very much like that of burnign oil...in fact that is what it is. There is no doubt that it is oil burning... the question is how does the oil get in there...

JDove...
If it is valve stem seal, wouldn't the compression check show a low number on that cylinder?

I will be doing some investigating today.... Will check back soon. Keep those suggestions coming.

Gurgen