After hot engine wont start and smells like gas

HOW many miles on the engine (REDUX)?/? 3.5L V6 engine? or 2.5 or the Diesel??????????
I'd have to drive IT to know.
let me guess the mech tested the car and it ran OKAY, so says" I can't find the problem. " ( what else")
you never told what the engine does , when it does fail and is Intermittent.
just that engine is ON. (runs)
and car does not move, sometimes.
what matters first, only when it fails, is does ENGINE RPM RISE fast and high when it fails.
see how that works, if it did the transmission is slipping (CVT are not fun here)
2500 RPM when it fails, right foot in to the throttle pedal this is transmission slip (failure)
if RPM are low failed, that is engine failure. (lean burning) or EGR stuck on or other problems , many.

lost engine power. has lots of causes; but this is gas(petrol) answer.

1: engine failing ,top cause , VVT or that chain loud noise? ?
2: spark plugs bad over 100k miles, (not diesel)
3: fueling bad, even bad fuel, or goes lean due to fuel pressure loss.(low) fuel pump weak?


driveLine choices day1, new not told gen 2, 2007 car.

Gasoline:
2.5 L QR25DE I4
3.5 L VQ35DE V6 <<<, seen in USA is it?
Diesel:
2.5 L YD25DDTi I4 no 2010 first

TransmissionCVT (Gasoline)

6-speed automatic (Diesel) 2010 up/

try new spark plugs and spark cop boots? 100k service point is is. and gaps will be way off ,when old

boots are here.

checkout NGK here. on COP boots x6

https://www.rockauto.com/en/catalog/nissan,2007,murano,3.5l+v6,1434436,ignition,spark+plug+/+ignition+coil+boot,10150

smell gas in the cabin Kenny, Fuel line is probably leaking, would have checked immediately by a qualified tech. This could be extremely dangerous if fuel is spraying/leaking on hot surface such as exhaust.

IT IS LOOKS LIKE A FUEL PRESSURE LEAKING INSIDE THE ENGINE OR DEFECTIVE FUEL INJECTOR LEAKING . TRY DISCONNECTING THE FUEL PUMP RELAY. AND CRANK THE ENGINE IF ALWAYS CRANK WITH OUT OF FUEL (CRANK WITHOUT START) YOU HAVE FUEL LEAK INSIDE THE ENGINE
REMOVE THE INJECTORS RAIL UP EVERYTHING CONNECTED,PUT BACK THE FUEL PUMP RELAY TURN THE SWITCH ON AND FIND WICH ONE IS LEAKING. (GASOLINE IS FLAMMABLE TAKE CARE)

Thermostat Stuck on warm up & or you have
a possible head gasket failure & I would suspect
a loss of coolant.

If that is the case, you have a ruined exhaust converter &
O2 sensors as well & a $5,000 plus repair bill coming

Don't know why you would expect to smell gas

Could be the fuel pump

sounds like a partcially stuck open thermostat on engine cooling system

Have you checked your glow plugs? Sounds like one or more may be faulty.

not sure about gas smell sure its not the smell of overheating vehicle. If it got hot the thermos stat didnt open or antifreeze was froze in the lines and couldnt circulate through engine

hav car scanned for free at a parts place--that fan shud be fixed engine wont start cause a sensor keeps it that way from overheating--also certain modules age and become hot and need to cool to function--u may need a throttle body cleaning

Try having the area that the hose was disconnected from steamed cleaned, or go to a car wash wash and spray the area. It might help, that is if you already haven't done so.