Last Wednesday I returned from a flight out of town to my 2008 G35 that had been sitting at the airport for 4 days. Get in and hit the button - nothing. Get a jump from the airport security and all is good the entire way home. Next morning - same exercise but I opted to have a friend take me to get a replacement battery. Purchased the Duralast Gold from Autozone.

As an aside, since before Christmas I've been having a "warm stall" issue. Car starts fine cold but after it's warm and started the RPM's jump to about 1100 but fall immediately to about 500 sounding like it's going to stall but never does.

Since the new battery install there have not been any issues with needing a jump (obviousely, right?) but the warm stall issue still exists.

This morning I'm heading into work, slowing down for a red light (my guess is that I was doing 10-15 mph) and the car just quit. Put it in park - tried to start it - and it would not turn over. Lights still working fine, radio fine, everything else seems fine. Except that the car won't even attempt to turnover - not even a little. Call Infiniti 24hr road side and they call a service out to get me and the car. Driver tries to jump it with a jump start box but there was nothing happening as far as the motor turning over. He mentioned that the car smelled as if it had overheated. I never looked at the temp gauge and by the time he arrived the car had been sitting for almost an hour.

Car is at the dealership now so we'll see what they say. I'm guessing alternator but who knows at this point. Needed an oil change anyway so all is good.

Update:

Had a missed call and message from the dealership that the battery was fine and that the tow truck driver may have been correct about the smell. It appears that "we had no luck in jumping the car off and as result believe we may have to change the engine because of something frozen - we haven't identified it as of yet - and will keep you updated"

That was message on my voicemail.

I'm hoping I don't have to go through any issues of having to prove that no fault was mine. Sure I play, but for the most part I'm pretty gentle on the car.

Without the overheating smell, exactly what my wifes nissan did earlier this year. Ended up being the crankshaft position sensor. Tends to be reoccuring problems with nissan products.

which may be true, but today's cars have idiot lights for both low coolant and high temp.

also, this would be an easy blame thing when they called. which is why I am curious what happened.

the usual checks would be to look for coolant, oil, mixing of either, pull plugs and see if anything is hydro locked.
but to call and say looks like the engine is locked up and we don't know what is causing it is plain weird. and makes me curious.

I was a little worried that I may have missed something but it happened pretty quickly so I didn't think it was over heating. Turns out it was a valve wreaking havoc on the motor.

You bring up a good point - I think that some are guilty of doing so much in a car we don't give much attention to the dash board. I for one will be paying more attention; even though there wasn't any warning for what happened it's a good reminder that I should be watching for signs that something may be amiss.

I would think they would be replacing the heads for a dropped valve. Most likely there is damage from it to the head. Plus the valve needs to be replaced.

Was already thinking of getting something different anyway - now may be a good time.

Want something different link

This is what I'm concerned about. How would I go about finding out? I'm waiting until I can be face to face to ask questions. What should I ask?

Some of what I've come up with is:
What was replaced? Was it a short or long block?
Do I get a warranty on the new motor? How long?
Was the motor remanufactured?

if nissan's warranty is like gm's you will only have the remainder of your factory warranty(3k miles) on the new engine

You have a new motor, treat it as such. Most likely, your rings are already seated, which is why they put 50 miles on your car.

This is what I speculated. From what I read, they should have seated the rings in the first few minutes of operation. They didn't give any specific instruction so I'm driving it like I would a new car.