2010 Sport Seized motor

1yakini

Hey guys i joined the forums a while back to read and get ideas when i bought my 370 a year ago. it was a 2010 sport 6mt with 44k on the clock. I got a good deal before it was even prepped for the lot and jumped on it. When i picked it up the dealer replaced the rear subframe because the bushings were shot and dealer records showed it had a new clutch about a year prior, from the write up it looked like a CSC failure. SOOOO this was supposed to be a weekend car that i could work on and take my time with. I did not get an extended warranty because i felt with the miles and all dealer service records i would take a chance. OOPS.

I have had it a year and the only mechanical upgrades have been intake and cat back. i haven't done a lot with it because most of my money has been invested in my q50 since i DD it. Last week i was driving to the gym and when shifting and accelerating in 2nd i heard some rattling which sounded like some **** the tires were kicking up under the car... not metallic. The car is loud so i started paying attention and it would rattle then go away once i got moving. I figured i had something caught on the driveshaft or something so i drove slow the 3 miles to the gym.

After i lifted i came out and looked the car over and didn't see anything hanging or loose underneath or in the engine compartment so i started her up and slowly eased out the parking lot. as soon as i went from 1 to 2 the rattle came back so i turned around and decided to investigate further. I looked as best i could and saw nothing loose so i drove it again and instead of shifting over into second i kept it out of gear, stopped, and heard the rattle consistent so i cut the motor. Now i know its not the drivetrain and i looked over everything again. Nothing. I got back in and >>> engine is seized. it wouldn't crank. i said oh **** and at first thought the clutch went bad and it was stuck engaged but i could roll the car with the clutch pushed and not when released. i tried pushing it and popping the clutch but the car stopped rolling instead of turning the motor. Oil had been changed a few weeks prior and was still full and clear. i had to call a tow.

Took it to a local shop and paid for them to tell me what i told them already. so now i have a 9 year old Z with 47k on it with a bad motor. I talked to the dealer and Corporate and am being told Nissan might cover the motor but i have to have their tech tear it down and assess what happened. The tech and service manager were telling me they have never done an engine swap at that dealer in the 15 years they worked there and the only ones they had heard of were oil starved for various reasons. i tried to tell them the oil wasn't it, i had good pressure and recent change.

Without a tear down i think (maybe?) the tensioner went bad and when rpms dropped between shifts it loosened enough to jump timing and i dropped a valve that (maybe?) wedged in the cylinder. I really cant think of what would have caused this without some indication or smoke or knocking etc. the damn thing just rattled a few seconds then shut off. And the dealer is saying the valve trains don't fail. I honestly don't know and I'm going to have to pay for the tear down and hope they cover a new motor.

Any ideas or suggestions from those of you experienced enough with the VQ i would love to hear. If they don't cover it I'm going to throw it in the garage and save for a built long block.