Because you are neither an auto mechanic nor someone who has knowledge about car engines, your ability to determine the status of your used Toyota engine may be limited. However, there is one practical way in which you are able to determine the possible status of your car engine.
If you own a diesel used Toyota truck, and you observed that there is black smoke spewing continuously from your tailpipe as you cruise around, then something is not good with your engine.
Black smoke could mean there is incomplete combustion of fuel in the cylinder area. The fuel odor is prominent and your used Toyota sedan is spending more fuel than usual are indicators that excess fuel might have leaked through the cylinder. This might not be serious trouble for you but you must bring your car for maintenance as soon as possible.
When some engine oil had dropped into the cylinder, blue smoke would emit from your used Toyota tailpipe when your engine begins running. Don't be amazed seeing blue smoke coming from your tailpipe. You should expect it to be happening with second hand vehicles like the used Toyota that you owned.
Worn out gaskets, seals, and O-rings are the possible causes of engine oil reaching the cylinder, eventually causing your car's tailpipe to breath out blue smoke.
White smoke is usually connoted with something that is good but not in the case of your used Toyota engine. The antifreeze agent or water that had entered the cylinder area would cause white smoke to emit from your exhaust pipe when the motor engine starts.
Gaskets that seal the entry of antifreeze or fluids to your cylinder area would fail once engine temperature is always above the normal level or worst your engine had overheated. Thus, it is always good to check the level of your antifreeze as well as the engine temperature.
In all of the circumstances described above, it is always advisable not to restart your engine as soon as you took notice of the smoke color that is belching from your tailpipe. Check the levels of your fluids, particularly the motor oil, water and antifreeze, and the smell of fuel.