I have a brand new 2003 Z06 in September 03. Has 400 miles on it now. Have already had catalytic converter replaced due to engine breaking up, poppin noise in rear, and black soot on bumper - {car is Millenium yellow} very disheartening ! Same symptoms have restarted again. Anyone experience similiar problems with their Z06's? Thanks for any help.

 

what did the dealer say is the problem?

 

what does that mean?

My exhaust pops while shifting when the engine and exhaust pipes are cold for about the first couple of minutes. Thats due to the hot and cold air in the pipes and is normal.

Never had that problem. Maybe the engine needs to break in a little more to let the rings seat. Maybe its running very rich. Maybe bad valve seals and oil is getting by.

 

Dealer says it's the cat again. I can't believe that these can't are defective...maybe they are missing something???

 

The black soot on the rearend may be coming from the rear diff leaking. The exhaust noise is normal.

 

ZPerb... I also have a new 2003 Z06 that I picked up at the dealership on 10/29/03. It now has about 1,200 miles on it and the exhaust on mine does "pop" a little bit too. As far as the soot on the rear bumper, well I have not had that problem, but I agree with AV8ter that perhaps you need to put a few more miles on it before letting the dealer work on something that might not be broken. It's sickening to think you've spent that much money and problems are already beginning to develop. I hope everything works out OK!

 

if you are getting black soot on the bumper, the differential must be burning the fluid...

 

has the dealer done all the engine checks to see it is not dump raw fuel into the cats which would cause them to fail?

is the car exhaust smoking blue or black smoke? does the car seem to run right?

what made you take it in the first time?

 

Haven't experienced this problem but if the cats are burning out from raw fuel then I would suggest they check the ignition system. You may have a plug that is not firing and dumping the fuel to the cats. This would also explain the soot.

 

are rear diff leaks common?

 

Yes, rear diff leaks are somewhat common.

 

Did you install an alarm system on the 03? If so, read this:
Subject: Misfire DTCs and Catalytic Converter Damage Due to Installation of Alarm Systems
Source: Chevrolet Dealer Technical Service Bulletin
Number: 02-06-05-004

Models: 2003 and Prior GM Passenger Cars and Light Duty Trucks, 2003 HUMMER H2, 2003 and Prior Isuzu Light Duty Trucks

General Motors Engineering, in an effort to determine the root cause of catalytic converter damage, has determined that aftermarket alarm systems incorrectly installed in vehicles have the potential to cause misfire codes and damage to the converter. These alarm systems use a circuit interrupt which utilizes the ignition circuit on the vehicles.

These alarm systems utilize mechanical relays and normal vehicle movement can trigger these relays to engage and disengage the ignition circuit while the vehicle is in motion. These disruptions of the ignition circuit, which occur in milliseconds, may cause more fuel to be commanded. Over time, this dumping of fuel on and off again can cause misfire codes and ultimately damage the converter assembly.

Engineering could not identify any alarms that utilize solid state circuitry that would eliminate this concern. Because of this, it has been determined that all alarm systems must be routed through the starter circuit in order to avoid this condition.

Dealers must be aware of this issue and take note of the wiring on vehicles with alarm systems that come in for repair, particularly for catalytic converter damage that seem to have no known root cause.

 

[Yes, rear diff leaks are somewhat common./]

Must be a cold weather thing. I know quite a few Vette owners from Florida and California and to date none of them have had rear end leaks. It seems that when I see it on the forum it is normally from up north where it is too cold for me or my vette. Use to live there and I am SOOOOO glad I live where I DO!! Sunny SoCal!!

 

Are you getting a code or something to tell you the car is so rich that it is blowing soot. My MY car is always "sooty" but it is IMHO the brake dust curling and sitting on the ledges in the rear. Honestly, I can't drive 10 miles without black dust everywhere.

 

Anything, including road contaminants, can be picked up. ZPerb, if you haven't checked the inside of your exhausts yet, do so. Run your finger inside them, and if it isn't coated with the same material, something else may be at work.

 

I'm in Toronto. Cold here.

No problems. New 2003 Z06! Sounds great... looks great!

Runs even better in the cold. PUrrrrrrrrs!

Going to do the 04 shocks too. On order! hehehee. Santa is coming...

Bill.

Take your car back to the dealer and let them figure this out. Your mileage is way to low. It could also be that your car is buring oil ????
:D

 

Looks like ZROCK might be on to something!

 

I would see if there is a fellow experienced Z owner in your area to give you a second oppinion of what you are experiencing. I have break dust all over the rear of my Z. When mine was new it was worse.

 

Like others have said the popping is totally normal esp. on deceleration. The stingers I have make it even more pronounced, but I like it. People who ride in my car sometimes ask what's wrong w/ it (they're not car people).

As for the "soot" on the bumper... milleium yellow is very bright and will show lots of dirt when up close. B/C of the aerodynamics of the cars the rear bumper gets very dirty very fast.

You could have a differential seal leak causing gear oil to be blown out onto the bumper. I lived in Virginia and it's hot most of the year and my seal leaked. The problem is because the driver's side half-shaft cover is improperly maufactured. The groove cut for the ring gasket is too deep. Thus, there isn't enough pressure put on the seal. The replacement half-shaft cover is supposed to be machined correctly and will fix this problem. I had mine done and it hasn't leaked since. If you run you finger on the back side of the plastic tub under the trunk it'll be oily if you're leaking fluid.

Lastly check your car for oil consumption... that causes black "soot" all over the bumper. Some '02 plus cars can have valley cover seal problems causing them the suck oil. Just keep tabls on that. Good luck :cheers: