I have a '03 Nissan 350Z 6 speed that consumes a lot of oil.?

[silverz]

Also a number of oil leaks that have been repaired under warranty. The car is so bad now that it is using 1 quart every 265 miles and Nissan says they will not fix the engine because I have aftermarket products on it. They were on it when they did the other work under warranty. I have a tuned exhaust system, air intake & intake plenum, nothing that could hurt the engine. I suspect that the car has bad rings from the factory, found out other Z's had bad rings from google searches. The tail pipes are black inside and have a greasy like build up in them. I have seen a trail of exhaust fumes at times under acceleration. Nissan has replaced engines in other Z's with this problem, they are using my simple mods as an excuse to not fix it, even though Nissan had me do an oil consumption test to check out the problem. Nissan found that the car was using oil as I stated, then they shut it down and say they will not fix it. What do you think I can do to get this resolved? Thanks for your help!

I guess I failed to mention I have had oil issues from the very beginning, long before I put the exhaust and intake on it. I first noticed the car using oil at a rate of 1 quart per 1000 miles when it had around 7,000 miles on it. My car has been to the dealer at least 20 times for oil consumption & leaks. They replaced valve covers, gaskets and several other parts to make it stop leaking & finally figured out it was leaking from the oil pan, so they resealed the oil pan & in the process broke the seal on the timing chain cover which made it far worse than ever. I'm not sure how to know when all this became my fault. I just kept doing what Nissan kept telling me to do, keep going back to my originating dealer, who kept making my car worse. Now they are blaming me for the problem, which I believe is their way out, of really fixing my car, which they should have done over 50,000 miles ago, instead of just piddling with it and now shifting the blame onto me.

[JohnPaul]

It is up to Nissan to prove that the modifications caused the rings to fail. Not hard if your cold air intake is not a NISMO. The 2005 anneversary edition and 2006 350Z with the VQ-35HR Motor had the ring problem. The regular VQ35 did not have ring issues. Once I had a customer not change oil enough and once I had a set of poorly made valve covers restricting the crank case building pressure. I work on almost all the Z cars at my dealership. That  valve cover car also showed many other oil leaks. I have replaced at least  6 VQ-35HR 2005 and 2006 motors this year our dealership has done 10. All those motors were on manual transmission cars.

 So if you have a dirty air intake tract and non NISMO cold air intake your done your motor in with grit and dirt. I haven't seen a 2003 350Z consume oil  that was nissans fault except the one valve cover car it was caught way back in 2003. How many miles do you have? Keeping a good relation with a specific Nissan dealer is a good thing. Cyl Leak down test and compression readings when the engine is fully warmed up would tell nissan they have an engine issue with your car. And ask about if the technician checked the valve covers carefully. 5 years engine wear, this is a good thing you can install better pistons and ballance the engine assembly install headers high flow cats new flywheel larger intake tract 4 new camshafts then dyno tune. An chance to get even more power!

[nissanguy]

john paul is right, but you could try to put back to stock intake system, exhaust is fine then try another dealer just go in and try to start from scratch, if you are still under 5/60 power train warranty