In the "old" days, you would diagnose the condition of the engine by observing the nature and color of tail pipe smoke.
At start up, you may get a puff of bluish smoke, probably indicating leaking valve guides/seals. To further check that possibility, we'd do a second test, with the engine at operating temps: Drive at a constant speed, and accelerate hard. You should not see any smoke. If you do, it's probably worn cylinder rings, or a bad bore.
Next, while driving steady, let off on the accelerator, and coast for a couple of seconds, then accelerate hard again; a blue puff confirms leaking valve guides or seals.
White-sh smoke on cool mornings is normal condensation.
Oh yea, black smoke probably means rich mixture.