HeroHorse

Hello,

Before I am beaten to death in the comments about 'they all have this issue' or 'shouldn't have bought that model', I got a pretty decent deal on it and have been driving it for a few years now. The car has been great and has taken everything I have thrown at it. Until recently, I didn't notice much oil consumption at all. I am pretty mechanically inclined and can totally rebuild the motor if needed. I just want to discuss this issue, yet again, because researching threads everyone seems to have their own idea. I have just started writing down mileage/oil lost so I am guessing it may burn 1 qt every...lets say 1000 - 1500 miles for now. The car also has higher milage, about 140k.

So to start I have not done any compression tests or leak down tests. I will be starting here just out of curiosity though I do not think this is the issue. When the car is started it does not smell like oil or have any blue smoke at all. I never smell oil or see blue smoke at anytime now that I think of it. The oil also never looks burnt or dirty, it stays fairly clean.

Looking through posts I see many reasons to 'why' and that the problem cannot be fixed. Nissan says it is normal to lose 1 qt every 3000 miles. This seems a bit excessive as is but is easily I can easily deal with that. However, I refuse to believe the issue cannot be fixed because that just doesn't make sense. With a full rebuild of the motor, if the motor is the issue, it should be fixed. I often read about the PCV system being poor and that a catch can will help with the issue. This makes no sense to me, unless it is vented I assume? This would only work if the issue resides in the crankcase pressure being too high and shoving oil through the system to be burnt in the cylinders.

So a big question that I would like to as all of you is what CAUSES the excessive oil consumption in this model of car? A poor PCV system sort of makes sense, bad motor makes sense, but what exactly goes so bad to cause so much oil consumption? I know rings for sure but I really do not feel like this is the issue. Worn valves and valve seals would be an issue as well. The reason I currently believe that this is not an issue (without doing tests) is that it does not have any of the symptoms such as blue smoke, burning smell, black oil, ect.

I hope to hear some helpful replies that could either help with the consumption or eliminate it. I would appreciate not 'smart' responses about how this year car is and I shouldn't of ever gotten it. I would much rather have a 07 or 08, but they are super expensive around here and i'm going to work with what I got.

Thanks in advance!

jellofuel

I have a non-revup, so haven't researched the issue too much in-depth, but I'd wager it's a combination of all these items you've listed here. Keep in mind there's no oil cooler as well, so the revup has hot oil, bad rings, poor pcv, and likely just vaporizes the oil and sucks it through the pcv like a straw. I have a used revup intake plenum, and it was covered in baked on oil, so I figure the pcv system shoulders most of the blame for the issue.

There was a TSB for this, so Nissan dropped the ball on this one. A rebuild is the only conclusive way to fix it, though I saw a revup owner on Facebook fix most of his consumption by adding an oil cooler. I imagine every z is different though, ymmv

Link to TSB info; https://my350z.com/forum/engine-and-...iscussion.html

HeroHorse

Thank you for your input. I never thought about the oil cooler. I may install an oil cooler as well as a vented catch can to see if this can solve the issue. I'm not into rebuilding it in its current state because overall the engine seems very healthy, just burns.

These mods are something to think about. I will start here and see where it goes!

RobPhoboS

At 140k - What oil are you using, and what kind of driving do you typically do ?

Desert Z

iTrader: (1)

I will state my own experience with my 06 rev-up engine (06 track coupe). Car has 110k miles. Daily driven for two years and the last 6 months strictly weekend car as it’s gutted from the seats back (getting caged soon, etc). I have owned it since it had 70k miles and it has had only synthetic oil in it, mainly Mobil 1 5w-30. Recently I installed a 500ml catch can but even before it I have not noticed ANY type of excessive consumption like all the threads extensively point out by owners themselves. The car is autocrossed and have done full track days. I have not had excessive oil consumption even then. I have measured carefully the day AFTER a track day (since the DE dip stick sucks) and the oil was slightly above the full mark since I added .5L before racing. There was very little oil in the catch can.

Date of manufacture in the door jamb reads 07/06 IIRC. I must have gotten lucky I guess.

Ultimately, though, the issue is with the piston rings on these engines. There is no "fix" since it require installing better rings with better design. I have read through all the threads and hundreds of comments.

jimbucks

Every car I've ever owned (and I've owned many) used oil to some extent. My 2006 350Z is no exception and doesn't use any more than I would expect. Common practice on any car is to check your oil occasionally and add if needed -- and not get paranoid if it uses a bit.

Sebastian777

Sorry to revive and old thread but did the catch can and cooler do help at all? Seems like my 05 RevUp with 120k is acting like your's did.

RobPhoboS

It'll be valve stem seals and piston rings to some extent.
A good catch can will always help the engine regardless, and an oil cooler is worth it for added capacity and if you use the car hard. But that won't stop it from burning oil sadly.
Either just live with it and keep it topped up until it becomes unbearable with clouds of smoke, or address the root causes if it's not a leak