Are Bad valve seals and piston rings covered under 100,000 warranty

Not likely rings on a Toyota but valve stem seals are very possible. If you have Toyota Extra Care extended warranty of if it was purchased as a certified used car then they are going to need to see receipts that you changed the oil every 5 ,000 miles. That is the biggest reason for this failure is lack of maintenance. You will also have to take it to a Toyota dealer for these warranties to be honored. If you have a warranty other than those then you may be able to go anywhere. Good Luck!!!.

Worn piston rings = Smoking 'any-time' engine is running ... Leaking valve steam seals = Smoking upon first start after extended park - then smoke clears up after engine has been running a bit ..... Extended 'warranty provider' can explain coverage more accurately than anyone else! Important > Approximately how much oil is the engine consuming in say - 1,000 miles? .. Does it require oil to be added between oil changes?