This 300zx I'm looking at is smoking out the exhaust, it was sitting for some time and now it is smoking. Smoke is bad on start up but dies down after being driven. Smoked barely after I parked it. It dissipates pretty quick, I don't have a sense of smell so I couldn't smell it for oil. Any suggestions on what it is? Also how bad is replacing motor mounts? Like cost and difficulty

 

could be bad valve seals. oil smoke is blue. coolant leak is white. black is running rich.

motor mounts easy. cost look online.

 

The smoke is white. It's not like a two stroke so I don't think it's burning oil, and the oil isn't cloudy, you think I should buy it? It's listed for 700 but If I decide to get it I'm gonna talk him down