tracked01z06

I've just recently started tracking my Z and this past weekend I consumed about 3 quarts of 5W30 mobil 1. So, approximately half a quart per session. The only thing that's been changed on the car are the brake pads. Everything else is stock.

I did some quick searching on this site and I found a thread that said that if I were loosing that much oil on an 01 or up, I should be concerned. Is this true? Any advice would be appreciated.

Thanks for reading.

kwhiteside

The 01's have a problem called ring flutter. At high rpm, quick decelleration (like the end of a straight, then slow down) some oil gets past the scraper ring into the combustion chamber. The experts say it is cosmetic and wont affect performance. Well, oil in your mixture does affect performance.

For my 01 ring flutter problem, the Mobile1 15w50 was by far the best. Two days at road atlanta in hot sun would use about a quart, even the Amsoil was using over two quarts.

If you do a compression check and leak down check and they show strong and consistent, you'll be ok if you keep on it.

Change you plugs each year too and look at them. My #7 plug (drivers side closest to firewall) was always a little oil fouled.

Even after suffering with the problem and telling myself not to get an 01 again, I might just end up getting another and living with it due to the price point.

tracked01z06

Kwhiteside, thank you very much for the quick reply! Very informative. I do believe I remember reading about the ring flutter when I first started looking into picking up a Z. I will put in 15w50 my next weekend out. So far, it's worked out I change my oil a week or so before I go to the track anyway.

Also, on cold start up, there's some clacking from the motor that makes me a little weary. It goes away completely as it warms up. After getting home from work, I had someone rev the motor up to about 4,000 rpm's and I heard nothing, it sounds healthy. Just at cold start up I hear the clacking. If it was an overhead cam motor, I would say it sounded like lifters...please forgive my ignorance.

davidfarmer

are you finding oil in your intake, or are you burning the excess? I've posted about the oil/air separator which is mounted on the bottom of the valley cover losing it's seal (you can remove and re-silicon it) if you are pumping oil into the intake.

imp zog

I thought (assumed) I had flutter with my 01 Z, but it turned out that almost all of that oil was getting eaten thru the intake from the PCV and valve cover breathers. I T'ed the PCV and valve cover breathers together into a catch can and T'ed the outlet of the can back into the two vacuum lines into the throttlebody to maintain the suction that pulls the nasty gases out and relieves pressure in the motor. That changed my oil burning to zero, and instead I catch almost 1/2 a quart each session. Your back bumper is probably well sooted/greased from the oil burning, as mine was, but after the catch can it stayed clean.

tracked01z06

davidfarmer, the thread you posted in was the one I was referring to in my original post. I have not checked my intake yet to see if it's there or being burned off. I would have to imagine that 3 quarts of oil is having to be burned off. But, who knows, I could be totally wrong. I have a lot to learn with these cars. Thank you for the reply!

tracked01z06

Actually, imp_zog, you're right. The back bumper is pretty sooty and dirty. It makes complete sense it's from burning off that oil. I'll have to look into a catch can. Thank you for the idea!

imp zog

After coming off the track, gently pull the hoses off the PCV and valve cover vent where they enter the intake, and you should be able to see if there is oil going thru them (for me it seems to be the valve cover vent that spews the most oil). Another check is to remove the intake plenum from the throttlebody and look for oil there.

I dropped an LS6 crate motor in last season and it pumped just as much oil into the can as the 01 did, so it seems to be independent of the 01's ring flutter. I didn't get fancy enough to try and drain the oil back into the crankcase, but once you see how nasty that caught oil is (black! smelly! ick!) you will likely do as I did and treat it as a circulating oil change.

longdaddy

i would second the suggestion to get compression and leak down test done. just to be sure.

ipuig

I had the same problem when I first started autocrossing my 01 coupe. Run a compression check or cylinder leak-down test to check the health of the engine. If it checks out here are some of the things I did to solve the smoking issue under hard acceleration while at the track.
- I no longer added the extra quart as stated in the owners manual, I just make sure it is at the full mark prior to starting the event and check it in between sessions.
- Added an oil cooler, getting the oil temp under control (< 250 F) appears to have helped.
- Switch to an oil with lower volatility rating. I'm using MOBIL 1's 10W-30 high milage, it has a little higher viscosity than the standard 5W or 10w-30 and significantly lower volatility.
My car no longer smokes under acceleration on track days and the high oil consumption in between oil changes has disappeared.
The noise you are hearing upon cold start-up is typically reffered to as "piston slap", there is a TSB out on it, it's common and it does not appear to adversely affect the engine. Mine has had it since I purchased it 4 years ago and it does not appear to be getting worse even though I autocross the car regularly.
I would not run the 15W-50 unless your car is strictly a track car, the viscosity is too high unless you are consistently above 250 def F oil temp.

95jersey

I had an 01Z that I got with 20k and it burned oil like crazy at first (like a quart in a few hundred miles). After only a couple months of ownership, I took it to the dealer to start the oil burn test. Before the test could be completed, I did a few HPDE's with it. After the 3rd HPDE, it completely stopped burning any oil and has done so to this day.

Not sure what happened...if the pistons finally seated properly after some high RPM usage, but after the third HPDE, the problem completely went away.

C66 Racing

Although high rpm ring flutter was most common on the 01s and there were several TSBs on the 01s, it is still pretty common to lose oil at sustained high rpm. I just got back from an SCCA double national weekend at VIR and as a comparison for you, I used a quart over the weekend which included a 30 minute qual, two 15 minute quals and two 30 minute races. Not as much as in your case, but not zero either. And my engine is essentially brand new as this was only the third race weekend on the oil. FYI, I was running the AMSOIL Dominator Synthetic 10w30 Racing Motor Oil (note - does not meet GM Standard 4718M) with an oil cooler and my oil temps ranged from 248-257 over the weekend.

As a note on ipuig's comment below about not running a quart over: keep in mind that GM recommends a quart over not for oil consumption but to help prevent uncovering the oil pump pickup point in sustained high G turns, particularly left turns. I always very mine is a quart over before going on the track.

ipuig

I know why GM recommended the additional quart subdriver. In my opnion I don't thinks it's necessary for autocross. At least in my case, running the oil no higher than the full mark along with the other modifications has all but eliminated my excessive oil consumption.

rustyguns

my money is on this one!

rustyguns

definitely do this!

fatbillybob

I'm 04 Z16 and racing I'm using no oil in an entire weekend. My bumper is clean and I don't seem to be sucking oil into the intake either. I'm racing with no catchcan. My car is the last of the breed. It seems to be better sorted than my race brethren. I also do not use the gas pedal as a light switch. I even right foot brake as I lift the throttle after heel/toe attempting gentle transitions. Maybe driving style has something to do with oil use? Throttle Lift off is when vacuum comes back in the intake right? Maybe when one dumps the throttle a big suck happens?

rustyguns

o4 has the best pcv system

ssdeuce

Can I ask a dumb question? Where is the PCV valve on the 04 LS6? I've looked online under the hood for the life of me I can't find it. :o

TS Motorsport

You guys can try Krank Vents, search for it on google.

C66 Racing

Understand your thoughts and use, but the OP was talking about tracking and I didn't want him to draw the wrong conclusion.