I'm so surprised......... not
 

After the new short block was installed and after the oil leak they gave me was fixed, I started watching the oil level like a hawk. With about 500 miles so far, it has dropped almost 1/2 a quart so far, so it's on course to loose about 1 quart at 1,000 miles.

One quart every 1,000 miles was what my average was when they installed the new short block.

I'm just going to continue to monitor it because I'm not going to deal with all this dealer BS all over again because I just got my car back about 1 month ago, after being in and out of the shop for weeks. I'm not going to be putting that many miles on it till Spring anyway cuz I'm too busy working.

If it's averaging a quart every 1,000 like before, Guess I will have to at the least threaten to sue them for a WHOLE new engine this time.

Whatever.

Man that sucks!!! Im getting my consumption test done, and Im afraid of getting a new motor that still burns oil. I dont think nissan has found/fixed the problem. If I were you Id call NNA and your dealer, and complain. Its sad for a car like the Z to have oil consumption. Good luck dude.

Wow, thats pretty crappy. Better luck with this motor and the dealer. In Ma. they have lawyers that will go after the dealer for you and dont charge you a dime. My friend bought an 06 Miata that was a lemon and he got a lawyer and made out really well. It took a little while for everything to go through, but he got reimbursed for everything he spent on the car. Car payments, insurance, even some mods he had in the car.

Oh sure you bet I'm gonna complain to the dealer but not until way after the holidays. I'm not even going to think about it until Spring and just drive and enjoy the car for now.

I just don't understand WTF happend with some of the '06 models. It's the same freakin' motor as in the Anniversay model.

I'm starting to wonder if there is one bonehead worker in Japan who assembled all of these bad '06 motors.

Where was it leaking on the other short block? Its not like it is hard to figure out with some simple testing, like a leakdown test for the cyclinders. I have heard of other motors (non nissan) that had a run of bad block castings that were pourous in a section that caused leaks.

I'm going through the same sh!t... but haven't gotten a new motor yet. My svc director claims to have spoken to tech at NNA and the have a new theory about it being caused my downshifting on 6MT (and from what I can tell rev-up motors). Anyway they think it may be the PCV valve holding open too long when downshifting and that it's sucking oil up which is being burnt.

This sound plausible to anyone?

If that was the case, it would smoke badly every time you let off the throttle. Simply test the pcv valve and rule it out or not. They should be able to figure it out for sure, and not just guess. But the pcv burning that much oil by sucking it up, I doubt that. Sounds like their "theories" are their way of saying they don't know what they are doing. If your car was at my shop, I could find the problem. Oil does leave an obvious trace when you loose that much that quickly.

of course it's plausible, it's called BLOW BY, and that's the primary cause of this issue

blow-by happens more when the engine is in zero-load condition and you rev it up, such as downshifting or revving in neutral.

during low load circumstances,

oil system = high pressure
combustion chamber = low pressure ... this pressure differential causes oil to blow by

under high load conditions,
oil system = high pressure
combustion chamber = high pressure ... less pressure differential, less oil blow by.

Thanks Wired.. I don't know much about this stuff.. so you think it is the primary cause? 4 qts in 1500 miles? I would think this issue would be more widespread it that's the case unless it's a design flaw with the VQ.

They tell me they're thinking of installing a secondary valve to prevent this. Think it'll work?

4 quarts in 1500 miles???!!!?!?! I think thats the most I have ever heard of. Have you told your dealer about this?? The blow by and pcv theory might be the problem, but I dont know it would cause 4 qts to be burned in only 1500 miles. My bet would be that its going through the piston rings and into the combustion chamber. Either because the ring design isnt correct, or they havent seated properly. Just curious, how did you break in your engine? I know I was going WOT since day 1, now it consumes about 1 quart every 1k miles.

I broke it in properly for the first 1200.. since then, I drive aggressively on open roads since I'm still learning the car.