I have a 2006 TL. All stock.

Right after fueling up yesterday the car wouldn't start.
Filled up full tank from empty.
Able to hear clicking from starter, accessories lit up as normal.

I sat and waited 5 min thinking about what to do. Turned the key again, and it started and drove perfect.

Later, stopped at the store, ran in for 10 min, came out and again it wouldn't start. Waited 5 min. Started right up again.

It idles fine, below 1K, steady, smooth.
The battery is less than 2 years old.
No CEL.

If I leave the car long enough for it to cool down - say after a drive I let it sit for 1 hour, it'll start up just fine. So this appears to be a hot start issue.

After some searching, I think it may be the coolant temperature sensor, but I'm not 100% sure.
I'm hoping someone is able to shed some light on this problem.

Also if you think it may be the coolant temp sensor, do you know where it's located?

 

When you say you hear the starter clicking, but it wouldn't start, am I to assume that the motor isn't turning, just solenoid click, is this correct?
If so, make certain cables are clean and tight, then see if the lights dim significantly when starter is engaged. If lights stay bright, start with starter, if they dim considerably, lack of power, start with battery check.

 

Sounds like the starter

 

I should clarify that. The motor does try to turn over. I don't know how to describe that sound in words. It's that sound that you would typically hear when a car starts - the sound like right before it actually starts.

I also want to add this I drove to work this morning. It started fine - I park in an underground garage - heated. I parked for 4 hours outside, it was about 40 degrees. It didn't start on the first try. Second try, I pumped the gas and it started up. So now even on a cold start, on a cold day, it appears to be having issues.

If it is a start problem, what would cause a starter to fail from a hot start? Too hot?
It appears like a fuel problem to me, but I really can't guess much beyond that.

 

nope. not a starter problem then. spark or fuel. turns over at normal speed?

 

Update:

Bad battery. I ruled it out because it was a 1 year old battery - not confirmed but indicated by the sticker on it.
I tested it at 8volts. Super dead. Took it to autozone to get it charged. Came back 3 hours later - bad battery.
Replaced. Car starts perfect.