What could be causing white or gray smoke not steam to coming from your exhaust it smells burnt sweet compression is fine and no oil in water oil?

1. Coolant leak: Smoke, especially white or gray in color, can indicate that coolant is leaking into your exhaust system. Coolant is a water-based liquid that helps cool down your engine, and if it leaks into the exhaust system, it can vaporize and create smoke. Check coolant levels or look for any coolant leaks around the engine or radiator.

2. Blown head gasket: A blown head gasket can also cause white or gray smoke from the exhaust. When a head gasket is blown, it allows coolant and exhaust gases to escape into the cooling system and exhaust manifold, respectively, mixing and creating smoke. Check for a blown head gasket by inspecting the oil filler cap or coolant reservoir for bubbles, excessive pressure in the cooling system, and any external oil or coolant leaks around the engine.

3. Oil burning: Smoke, specifically bluish or gray in color and having a burnt sweet smell, can indicate oil burning. Worn piston rings, valve guides, or other engine components can allow oil to seep into the combustion chambers, where it burns along with the air-fuel mixture.

4. Incomplete combustion: If the air-fuel mixture is too rich (too much fuel compared to air), it causes incomplete combustion, leading to the formation of black or gray smoke from the exhaust.

5. Vacuum leaks: Vacuum leaks can also contribute to white or gray smoke, especially if the leak allows air to enter the exhaust system. When outside air enters the exhaust system, it can mix with the hot gases and create smoke. Check for vacuum leaks around the engine intake manifold, hoses, and connections.