Too Tall Bob

Last week, I pulled the cats. from my stock '02 Z06 track car and noticed that now there is quite a bit of oil smoke coming from the exhaust under deceleration. The car runs fine, (in fact no better than it did WITH the cats on) but the smoke is the problem. I usually keep the oil level 1 quart above the full mark and normally burn 1-2 quarts during an 8-10 session weekend, and this weekend was no different.

Do the cats usually burn off any oil residue, because this is a new problem and I'll probably just put the cats back on.

Thanks...

tcmc5

I began having the same issue after removing cats on my track car. I believe the main source of oil is thru the intake, though my car may also have a ring issue as well. An effective catch can setup will reduce the intake oil but it's very difficult to eliminate it without eliminating the stock PCV system altogether - a step I'm about to take.

Red Gump

what year/mileage? might be time to freshen her up. how's your pressure?

Too Tall Bob

2002, 35,000 miles. Runs very good and the oil smoke was never an issue until the cats came off last week. Was not put into service as a track car until I purchased it with 32,000 miles on it. Oil pressure is fine...always above 40 psi.

I put 380 miles on it last weekend on the track and it only used 2 quarts of oil for the entire weekend, and it lives most of the day on the rev limiter.

JiminVirginia

Had the same experience in my old Supra when I installed a down pipe and exhaust system with no cats. It was valve guides. Smoke was most apparent on start up after the car was sitting for awhile. Do you have any smoke on start up?

Too Tall Bob

No,.... no smoke at start up....only when it's hot. I spoke with someone who was following me at the track last weekend and they said that the car smoked mostly under hard acceleration and just a little under deceleration into fast right-hand corners.

MitchAlsup

Since oil (blue/black smoke) is hydrocarbon in nature, the cats do end up decomposing and recomposing these substances into less evil molecules.

emf

Bob -- have you pulled the intake & looked at the TB? Interested to see if there's oil in front of / behind the TB blade. Similarly, interested to see if there's any oil residue in the intake.

Too Tall Bob

I'll take it off today and take a peek. If there is indeed oil going into the intake from the crankcase vent, can I just bypass the vent going into the intake and put on an overflow container?

BTW, we missed you at Viper Days last weekend, but completely understand the work situation. I put on ALOT of miles during the 3 days.

emf

That's what I would do for starters. The cats IMO would kill some of the smoke, but just end up masking the problem.


Yeah, still a bit unhappy about missing last weekend . . . although, somehow I have a feeling I'd have spent more time figuring out what Ed broke now, than anything

Too Tall Bob

Ed's day:
Session 1...2 laps, power steering pump goes kaboom. Lots of smoke in my mirror.
Session 2...2 laps, Lots of smoke again. Ed's 3-day weekend ends before lunch on Friday.

0Randy@DRM

The two stroke LS motor is what I call them. 1-2 quarts a weekend isn't that bad at all. You can put a catch can in there and maybe only burn a quart a weekend. I was talking to my sales guy at JE one time, the average Nascar burns about 1-2 quarts a hour. That I thought was pretty funny.

Randy

steve-d

Had the same sit w/my LT4. Oil bypass on hard accelleration as well on decel.

Rings and valve guides & a freshen up will take care of it, get you a bump in hp and reduce the profile of your right rear pocket.

Steve

Olitho

Hey Mr. Wupass:

I just read that the hot ticket for going fast is to bypass the little oil catch container and you just feed two drain tubes to the back of the car and let them vent just in front of your rear tires.

Well, maybe it won't make you faster, but at least I will feel faster as I can hopefully keep up as your are "drifting" through the turns.

fatbillybob

Can you explain how you do this? I think PVC dumps into the intake upstream of the TB. Catchcans are sealed so you would need to vent the catch can too right? Do you just delete the pvc for a one way vent valve and run a line from the one way into a catchcan that breaths to the atmosphere? If you are tracking the car only can you also dump coolant overflow into this catchcan without problems?

Too Tall Bob

Don't worry, you're plenty fast! No need for me to "grease up" those tires for you!

Carl Johansson

Hey Bob,

Lets make sure we eliminate the obvious first. have you tried running it without the extra quart - I put an extra quart in mine - seems like good insurance - but maybe it's worth it to just make sure the oil is at the recomended level - then run a few laps - I'd hate for you to just be slopping out some extra oil - and having it burn off.

Might be worth the time to check it out - at least.