This might be a tad premature, but I think I've reduced my oil consumption problem to a bare minimum (1/2 quart per 1000 miles). In going through what I had though was an unrealated problem, I think I found the solution. Here's a list of the different symptoms I had:

Hesitation during acceleration
reduced gas milage
reduced power
oil consumption (1 quart per 700 miles)
oil in the vent tube mentioned above several hundred times
black smoke during WOT runs at the time of the upshift
got my a$$ handed to me by a Honda
excessive heat coming out from under the car after it warmed up.
LOUD intake (much quieter now for some reason)
weird automatic shifting (wanted to down-shift excessivly)
hard shifts in the auto

Now a lot of these things didn't show up at first. The initial symptom was the timing chain rattle. Then the oil (probably both at the same time, but didn't notice the oil at first). Then loss of power, and all the rest basically at the same time after that. This went on over 40k miles. When I finally said enough and took it to the stealership (this particular one is actually very good), they ran a ton of tests. The bottom line is that all of my problems came from a clogged catalytic converter. It was explained to me that the clog was causing excessive back-pressure in the engine thereby causing the blow-by. There wasn't much more of an explaination from there, but we can surmise that its possible the excessive pressure found it's way past the valve seals into the valve cover and out the PCV system. Anyway, I installed a new high-flow aftermarket cat and now it's running perfectly. All my symptoms are gone, my oil level isn't dropping, no more timing chain rattle due to low oil levels, my gas milage is back up, no more exhaust puff at WOT, and the engine is now smooth as silk.

I can't say this fix will work for everyone, but it's worth looking into.

glad it worked out for you.. what high flow cat did u get and where did u get it ?

Was it covered by warranty?!

Cattman Race Pipe from Redlinemax.com (not the site. call Cory for pricing)

I have 126k miles on mine, so no.

Sounds to me you need a new engine. Man that thing must have been punished to need replacement so early. Usually smoke out the tailpipe is a terrible sign and oil consumption also. Isn't smoke out of the tailpipe a sign of piston ring failure? I think the only solution is to let it die and replace it. These engines are pretty much bulletproof.

The engine is fine. In fact, now that the cat is replaced, all the symptoms are gone. Please read the post before commenting.

Interesting..

I have the SAME TIMING CHAIN RATTLE as you... and these engines are not nearly as BULLETPROOF as the older VQ30's

Numerous posts of VQ35DE burning oil issues in 350z, G35, Pathfinders and maximas.

I am still waiting on approval for a new motor. My engine also exhibits POOR fuel economy, poor performance, loss of oil, etc.

Have the cat checked. Worth a shot if the approval doesn't go through.

smoke out of the tailpipe a sign of piston ring failure?

just because piston ring faillure causes tailpipe smoke, doesnt mean that a car with a smokey tailpipe has failed piston rings.

and seriously, read the damn thread before posting.

damn, that's good news George

Wanna come over and drive it? It'll chirp the tires at 80 now. I bet you can really **** off that redneck woman in her behemouth truck this time!

What kind of tires?

just curious, is the blow-bys (oil in the vent tube) described above that plastic curly host from the engine to the intake?

curious of this as well....is it coming from bank 1 (PCV valve) or bank 2 (closest to the radiator?)....I installed an oil catch can in my 3.5 and its working wonderfully...its trapping alot of oil...I didnt know city driving would make so much blow by....

wow chirping yer tires at 80 huh? thats alot of power....I mean I hear nitrous cars do that, but n/a

any of you guys with oil burning problems ever take a look at all 6 spark plugs? if you did, did you notice any signs of oil on them?

There is a service bullitin out for that, get it fixed under warranty.

Pilot Sport A/S with around 60% tread
That's the tube I was describing, but I'm not convinced that's were the oil was going. I haven't taken off the manifold (nor do I intend to: if it ain't broke...) or checked the plugs.
I think it shifted over a patch of bad pavement, but they deffinitly broke loose! Good times.Agreed. If you still have a warranty, don't screw with it yourself.

Interesting....I guess you didn't believe my diagnosis of the problem that it was all caused by your engine cover

I'm still losing some oil (1qt/1,500 miles) so the cover may have something to do with it....

I never added oil to my car. And i believe I went as much as 4500 mi once. The level doesnt budge.

You have a different engine.

Your car didn't spin the tires at 80, your tranny prolly slipped..... the maxima won't spin tires at 80, especially the tall *** gears you have

Did you read all of the posts before typing? I think the requirements to be a mod have dropped lately... Here: I'll for ya:
I think it shifted over a patch of bad pavement, but they deffinitly broke loose! Good times.

No issues with having to add oil, but my gas mileage sucks. I think I'll have to have the cat checked. I'm looking to replace the stock exhaust with a Ypipe and cat back exhaust and eventually a bump in the timing.

2.59 for premium is starting to pinch a bit at fillup time.

im paying 2.80ish for premium down here.

$3.15 for super today!!!! WTF!!!
I notice my 03 consumes oil as well....is this considered normal? My car is stock and I rarely beat the s**t out of it (that's what my R1 is for)...seems like those losing oil are pushing more horse than stock...

where would be a good place to take my car to have it check up on? Im not a mechanic or a pro at my car. Does nissan charge an arm and a leg for a check up? Not tune up , i just want someone to check on the parts of my car to see if its running correctly.

yeah drock, i drive to work on route 1, and I saw 3.00 for premium. man, all i gotta say is thank god im not living in europe.....

I had bad luck with IRA in Tewskbury, but good luck with IRA in Woburn. The service guy there was pretty decent considering he works at a stealership. Their facility is huge and have more techs than Tewksbury. I try to stay clear of dealerships but if I had to go I would check out Woburn. Its right at the intersection of 95 and 93

3.00 for premium not to bad around cleveland area I am hearing 3.09 for regular octane

This was about oil? You guys should start a gas $ thread, But anyway ya $2.89 in Seattle

how about noise level w/ your new cat?

I have the timing chain rattle at startup. I'm also considering a high flow cat and a cattman cat back exhaust.

The timing chain rattle was occasional at first, but now it happens all the time at startup

Dipstick read full and in 1.5 weeks which is about 650kms (1.5 tanks of gas) dropped to low.

Called the dealership... still waiting on approval.

This is absurd... Mentioend the cat thing to my service guys, they said its unlikely.. They do conclude the timing chain, poor fuel economy and lost performance is the oil.

I just got a new clutch instaleld 3 weeks ago.. Tried to chirp 2nd... its not there..even with new clutch. I wonder how much power i am losing here.

Actually, believe it or not, the car runs quieter now. Before the intake screammed, now it's much more subtle. I'm getting close to 30, so I kinda think that the reduced noise is good.

GBAUER whats the update on the oil consumption? What kind of oil do u use?

Wow! I'm experiencing the same symptoms. But not sure about the smoke part, but I'm beginning to Hate driving my car because of these symptoms. At this time with Super at $3.29 a gallon over here I cant take the crappy mileage either. I'll take a look at getting a cat. How much and where can I get a good replacement?

oh yeah and I don't appreciate the car digesting the Mobil 1 synthetic I keep having to put in there...

You are deffinately loosing power somewhere. You should be able to bark second no problem, even at 5000rpm's. Mine don't just bark but will actually spin and loose traction sometimes. It's been that way since it was stock also. Tires are new.

and the other guy gets rubber at 80mph LOL

agreed...sometimes I chirp the tires accidently at mid RPMs if I let go of the clutch too quick...if i speed shift 1-2...it will spin there for awhile (even with my 245 wide rubbers and modified suspension)...so usually I granny shift 1-2 cuz of the excessive spin...2-3 is no problem and will chirp nice and smoothly even if i speed shift...