ZeeOSix

No one mentioned it, but if your differential or tranny is leaky it can cause oil spots to collect on the *** end of the car. Then road dirt will stick to the oil spots.

Threed

Check for oil on the bottom of the side plates.

carnut101

How do you do this?

GeorgeZNJ

Whisling noise aroundwindows is common, it gets real loud well into tripple digits. The'yre designed to do this. Why?, I forgot, something to with pressure I think

z06inVB

Mine has always had black crap on the back of it. After I washed it Saturday I forgot to dry the back of the car and when I got home it looked like it had picked up anything that had been on the road. And my 01 has 83k miles on it has never had any work done to the engine and has no oil burn issues.

As for the door issue what code is showing for the door control module?

Skeld

Not sure what you mean by what code is showing for the door module. I don't have any sort of diagnostic tool to check it unfortunately.

The dots seem to have gone away for the moment - rinsed it off and drove another 20 miles or so and I don't see anything.

Also, I don't see any sign of oil leaking around the differential. Where exactly should I be trying to ram my head under the car to see what you are referring to?

Gary04Z06

Somewhere in the DIC it gives you those options. I don't have my manual handy.

RedLS1GTO

Don't be scared of crap on the back of your car. I just drove mine from VA to OH and back again... There is crap, road grime, dirt, you name it stuck on the back of the car. There is a vacuum back there when you are moving at speed and it sucks up all sorts of stuff that your tires kick up off of the pavement, etc. Long story short, If you don't see any other problems, stop worrying and enjoy your car.

Mello03

Bill Gates rich Get a tune! You will not regret that one.

Skeld

Worth it to get a tune when the car is stock? Previous LS1 experience with my 2000 Camaro told me that it was kind of a waste until you had a fair amount of bolt-ons at least, but that's not the case with the Vette?

BlackZ06

You don't need a "tool" to display the DTC data in a C5 Corvette .... go here ....

https://www.corvetteforum.com/techti...D=26&TopicID=1

When the AUTOMATIC display completes it will enter MANUAL mode. In that mode display and write down what codes you have.

A code looks like this ...... P 1234 C

The first letter will be either a P, B, C, or U ..... indicating which system the code is for.

The following 4 numbers are the code

The last letter will be a C or an H (sometimes both).

Post the ENTIRE code (as in the example ..... P1234C), and list ALL the codes found.

You're correct, there is little benefit in a "tune" if you have a stock engine.

Mello03

Not to start a war but I would have to disagree with you. I would have to say that there are many people out there that would too. AND, there will be many people out there that would disagree with me as well so no hard feelings. I am relatively new to the 02-04 Z but have had modded cars in the past. LT1, LS1 and LS2. All started out with a intake and dyno tune first. Never regret one of them. All were rich from the factory. To me 10-12 RWHP is worth it not to mention limiting torque management and shift points. My GTO gained 12-15 RWHP from an intake and tune. You figure dollar for HP gain I think it is a good value. JMHO. I picked up 15 RHWP on my GTO (now supercharged) going from 91 octane to 93 octane. Yes that is a modded car, but I believe and have seen that there are benefits to a tune on a stock car.

Skeld

Cool. Thanks for that tip. And good to know I'm not a total noob, got one thing right!

When I started this thread I was kind of paniced since I had just bought a car that was spewing black **** on the back of itself -- it seems to be not doing it at this point. I can only conclude that it was just road debris or it was carbon/fuel. I will keep an eye out, and thanks to all those who posted.

BlackZ06

I'm not gonna start a war either .... but let me point out a few places where you're wrong ...

To me 10-12 RWHP is worth it not to mention limiting torque management and shift points.

Since the Z06 does not have Torque Management or Shift Points (it's a manual transmission if you haven't noticed) "tuning" those items has little effect ....

I picked up 15 RHWP on my GTO (now supercharged) going from 91 octane to 93 octane. Yes that is a modded car

Show me anywhere in the state of California where I can buy 93 octane ...... doesn't exist ..... and tuning for a supercharger .... duh .... yeah I'd expect some difference since the PCM is "tuned" for a NA vehicle.

I'll stand by my original statement ......

"there is little benefit in a "tune" if you have a stock engine"

SilentFright

I think you have been reading too much into the anti-2001 Z06 bullsh*t threads in this section. Condensation plus the carbon buildup in your exhaust will get deposited on your rear bumper no matter what year your car is. Enjoy your Z and stop taking these internet oil burner accounts as pure fact. I remove 3/4 of a quart from my catch can every 3,000 miles and my car is a 04' not a 01'. Where do you suppose that oil would have gone if I was not using a catch can?

Mello03

Thanks for pointing out that the Z is an M6. I also think there will be plenty of people that will disagree with you on torque management. Are you 100% sure the Z doesn't? If you ARE and can tell me why, then I'm all ears! I obviously wasn't just referring to the Z06 but more to the stock engines I mentioned. Also, I know that 93 octane isn't available in a lot of places on the west coast. I lived there for many years and that statement was just an example of what tuning can do, even if it's just on the AF ratio. Search around this site brother or any site, LS1 tech, or LS1GTO, even tuner boards, and you will find that many people agree that a tune on a stock car is well worth the money. Just because you don't think so doesn't mean "there is little benefit in a tune if you have a stock engine." That statement is very subjective. Peace.

RedLS1GTO

I got my 02Z tuned when it was 99% stock. Only mod was a Corsa Competition Ti exhaust. It now runs smoother, has more throttle response, and even gets a little better gas mileage. Here is the difference on the dyno. Without a doubt worth the $. Look at the a/f ratio and how rich the factory tune was. Peak gain was 17hp and 21ft-lb of torque and a TON of room under the curve. No other mod at the same price will give that.

ZeeOSix

I have to say that I've never seen any black spots all over the rear of my 2002 Zee ... and I don't baby it all the time either.

only59

this is an easy fix..

Soap and water. Don't fret, like mentioned above, The back of these C5's are doomed to dirt !

IF this was a serious OIL BURNING issue your complaint would be way worse than a few black dots...SOOT all over the place , the back of the car would look like someone sprayed it with black powder !

I had a 1970 Silver GTO, I know what OIL burning looks like , and it ain't small black dots !

My black 01 Z06 gets a quick rear wash once a day just from the dust and debris from the road. It's part of life now.

dieseldave56

I have yet to know of a car now days come from factory that is tuned rich. EPA and Carb ( Calif) would now allow it as limits are strict. The auto manufactures have enough problems getting by the mandated specifications now . My experience has show just the opposite is true , that engines run as lean as the manufacturer can get them.

If you're concerned about oil consumption, then monitor the oil useage. I consume less than 1/2 quart per 3000 mile oil change in the '01 Z. The 2000 FRC has about the same consumption , as the wife does not race professionally ( that I know of) But the reports from just this forum of members varies widely. The F bodies as well.

All C5 and C6 Corvettes consume oil one way or another. C5's ( LS1 is worse) have very inadequate PVC systems that can not draw crankcase gase build up as the is little to no vacuum produced at high engine speeds w/ no or low MAP WOT. The baffle does not work as designed on the C5 and the oil/air seperator(s) also does not work on the LS2 design ( read C6 section , as those guys are also consuming oil that is deposited in the intake manifold. They are modifying the PVC system just as we C5 owners are) . The answer is to allow sufficient air flow from the crankcase and thru an air /oil seperation system ( that works) and return the clean air to the manifold/ throttle body. http://www.corvetteactioncenter.com/...5/sequel6.html Run down pg 6 till "New Rings & Revised Oil Control". An 2005 interview by Hal Halverson ( who did the 2002 interviews with Dave Hill and John Juriga about the 2001 and 2002 LSx engine) with GMPT engineers MarkDamico and Jordan Lee , who speak candidly about the C5 LSx engines and the LS2 engines.

What was of keen interest to me was that the LS2 specs out piston ring tension lower than the C5 ( before 2002 revised rings). The rings on the LS2 are thinner ( less contact with clyinder bore) as well. Jordan Lee say that the focous to oil consumption was closer ring to cylinder bore dimensions , rigid bore tolerances and a better PVC system that incorporated not a baffle to seperate oil from foul crankcase air but oil/air seperator(s) , two that are placed on both fresh inlet and fouled outlets. These oil/air seperators were designed using a patiented technology by Dana.

Most interesting is that the LS2 PVC system can be applied to the LS6 and LS1. But LS2 owners have the same oil consumption to various degrees as the C5.