Usually a puff of blue at start up means poor valve seals or loose valve guides.
Other symptoms depending on how bad it is are blue smoke under engine braking, like slowing from highway speed and when it gets bad Smoke at idle but not with the engine under load.
White smoke = Blown Head Gasket or cracked head. Black Smoke = Overly rich fuel/air mixture. Blue smoke = Oil burning. Blue smoke at startup usually means worn valve seals.
White smoke when cold - normal condensation burning off Blue smoke when engine is at normal operating temperature - could be bad valve guides or seals.
burning oil
Smoke from a diesel engine on startup can indicate several issues. Blue smoke often suggests oil is being burnt, which could mean worn engine components or seals. White smoke typically indicates unburned fuel, possibly due to cold temperatures or fuel system problems. Black smoke usually points to an excessive fuel-to-air ratio, indicating issues with fuel delivery or air intake.
If it only smokes at startup and the smoke is blue this is normally a sign of worn valve seals or guides. White smoke is a symptom of blown head gasket. Black smoke is a symptom of overly rich fuel/air mixture.
Shagonigei means little blue smoke
Blue smoke at startup, that clears up within a few minutes is normally cause by worn valve seals. Blue smoke that continues is oil burning. Black smoke is fuel burning from an overly rich fuel mixture. White smoke is normal at startup, especially during the winter, but if it does not dissipate rapidly, it can be a sign of coolant entering the combustion chamber. If it is coolant, it will smell sweet, you will be loosing coolant, and this is a sign of serious trouble. Usually a blown head gasket or cracked/warped head. First is what you call smoke BLUE, BLACK, or like FOG or STEAM ??? Black smoke usually fuel Blue smoke usually oil Steam/Fog usually water or coolant Now , the big question is whats the cause? Flooding fuel injector?, Worn piston rings?, Blown head gaskets?
If your RX-7 is smoking at startup, it could be due to a few reasons. Common causes include oil leaking into the combustion chamber, often from worn apex seals or oil control rings, leading to blue smoke. It could also be a sign of coolant entering the engine if there are issues with the water seals, resulting in white smoke. Additionally, a rich fuel mixture can cause black smoke, indicating potential fuel system issues.
Blue smoke means oil is getting into the combustion chamber; usually mean worn out piston rings.
Pcv valve needs changing
Blue smoke means that you are burning oil through the exaust system and can mean anything form a head gasket to bad rings.
White smoke that smells sweet, is coolant in the combustion chamber, normally caused by a cracked head or a blown head gasket Blue smoke, the engine is burning oil. Black smoke, the air/fuel mixture is too rich. A small amount of white smoke at startup, that goes away, in cold tempertures is normal.