kwhiteside

My 2001 Z06 drew attention at Roebling Road coming off the straight into the first turn because it always blew smoke.

Went to Road Atlanta last Monday and more attention from both drivers and this time the track starter who has a good view of turn 1 off the straight.

It's embarrassing being the talk of the track when the talk is negative. I've been trying to figure it out and take care of it. I put a catch can on between Roebling and Atlanta, didn't help. Well, I found this article and am pretty positive it describes the situation.

http://www.c5registry.com/2k2z06/page5.htm

Ring Flutter on the 2001 Z06's causes the rings to not scrape all the oil off when at high rpm and low load. Well, hitting the brakes after 140mph 6000+ rpms causes high RPM, low load. So you hit the brakes, leave oil in the combustion area, then blow it out when you accelerate thru the turn. Supposedly, this phenomenum does not affect the compression, and does not wear the engine. I'm having a compression check and leak down test done today. I'm hoping they say looks normal and its not new engine time immediately. Maybe I'll get a custom license plate - PUFFDAD.

Jason

Good info to know.

varkwso

I saw you were still smoking at Road Atlanta....

kwhiteside

Compression check came back 195 -200 psi on each cylinder. Extremely consistent and extremely strong.

I'm pretty sure that my car suffers from the problem described in the tech bulletin for the 01 Z's. Ring Flutter doesn't scrape down the oil properly at heavy RPM / low Load. I've read that I can actually still get it taken care if I can prove it uses more than a quart per 1k miles. I've even read of another forum guy taking it to Tom Jumper Chevy within last year and they actually did the procedure for him. I'm sure I can prove it if I really needed to. It will use a quart at a track day, but to prove it I would have to not add any oil and take it back to dealer for them to log it. this might also mean if I was running low I would have to end my day to preserve the proof. Since it doesn't affect performance and isn't leaking any oil at the track, what would I gain for all the effort?

I think I'm going to live with it unless some track black flags me and kicks me off or I start noticing a performance issue. They say even if I get the fix from the dealership, it will not improve performance in any way. Just lessen the oil usage problem.

longdaddy

i have seen couple of ls1 powered cars do exactly this pretty consistently. same deal with black flags, embarrasment etc, neither car had any long-term issues/damage as a result.

SLandstra_Z06

Blowing oil smoke out the exhaust on deceleration is typically caused by one or more bad seals on intake valves. I would replace them all, an inexpensive and easy fix if you have the proper tools.

Ring flutter was only a problem in 2001 LS6 engines. Newer engines don't have this problem.

Frank Gonzalez

Posted by Frank on Steve's computer at the track.

Z06_BluByU

frank, his car is a 01 z06

kwhiteside

Ya, mine is that first year Z06. No harm being aware of all possibilities though. If I had a bad seal or two, wouldn't that have shown up as a lower compression cylinder?

SLandstra_Z06

I had an '01 Z06 and had high oil consumption on the street. I had to have the dealer log every oil addition and the mileage when oil was added. After a month of that, they authorized a replacement of the piston rings. I had them upgrade the cam to an OEM '02 cam and replace the valve springs with 2002 OEM valve springs while they had it apart. It cured my oil consumption issues completely and raised the horse power and torque to an '02 spec. car.

You might want to look into that.

Good luck.

Steve

kwhiteside

From 2002 Press release

This upgrade to the LS6 engine's output is the result of new hollow stem valves, a higher - lift camshaft, a low restriction mass air flow sensor and a new low restriction air cleaner design. Eliminating the PUP converter from teh exhaust system enables better flow of spent gasses and reduces vehicle weight.

I'm already running Vararam for airflow, catless, LS2 TB, so how much of the 20hp will be left for just the camshaft upgrade. If I went that route with my free flowing air (also fast92) I would probably go with a bit more radical cam than stock 02. Would the dealer even do that? would I want the dealership doing that? BTW, can you share what those extras cost you from the dealership. PM if necessary.

tcmc5

Before you start messing with the engine you might want to eliminate the possibilty it's coming through the intake. I don't know what kind of catch can set-up you've got but I tried several and didn't solve the problem until I ran the hoses to a vented catchcan and capped off the intake manifold. My car was pumping about 8-10oz per session into the can. Smoke on decel dropped significantly. One way you can check your intake is to push a large rag, maybe an old tshirt, thru the mouth of the intake then remove it to see how much oil it picks up. I was amazed when I did this.

kwhiteside

Great, I just started learning about catch cans and got a setup from Vengeance. I think it is the elite type can, with a filter cap replacing the oil cap. The valve cover vent is just capped. After a whole day at Road Atlanta there was only about 1.5 inches of oil in the can when I drained it. I'm not sure if it is best, I'm trusting the local speed shop recommendation on this one.

trackboss

On my '99 I get some smoke and also oil in the intake. I have dual cans and a Z06 valley plate pcv. The valve cover breather can gets absolutely no oil. The pcv gets an ounce or so after two days on track. Oil lost is very minimal. I would be I mine gets past the rings. The intake is always wet.

mcar00

I used to get black flagged all the time in my C5 Z06's. As soon as you remove the cats they smoke like crazy. I had a new '01 and a new '02 that both did the same thing after I removed the cats.