Hi this is my 2011 G37S convertible with just a muffler delete, everytime I cold start it blows out white smoke in this specific picture it was 39 degrees the smoke goes away as the car warms up, im hoping it’s not a head gasket leak doesn’t smell sweet or leak coolant as it seems, coolant temp runs normal any advice or suggestions?

 

Here is an article that describes what you are seeing
Why Do Car Exhausts Smoke in Cold Weather? | Cars.com

 

If its only with cold weather, its most likely condensation.

 

My 2011 G37 coupe did that in cool/cold weather all of the time. Even the first day I took it for a test drive it did it.

It’s just a characteristic of the VQ37 engine

 

All cars do this upon cold startup not just the G/VQ.. Condensation accumulates in the exhaust as the metal cools especially overnight and in cold, damp climates. Upon initial startup, this moisture evaporates and exits as steam. Completely normal.

Now, if after the car has warmed up and driven for a while and you still see white (or black/ blue) "smoke" then there is potential cause for alarm.

 

Is it smoke or water vapor?