A blown piston ring is a major mechanical problem. The easiest way to determine this is by checking on a bluish tint of the exhaust smoke.
It sounds like a blown piston ring, you should get it serviced soon.
Do a compression test.
Could be a blown head gasket or the piston rings Could be a blown head gasket or the piston rings
If there is oil getting to the top of the piston and burning then you have a blown head gasket or the piston rings are worn or broken. Engine must be disassembled.
There are a couple of things that can cause oil to get into your coolant reservoir. A blown head gasket or a broken piston ring are the most common causes.
A blown head gasket can allow coolant to see into the manifold, and out the exhaust. A broken piston ring can also cause this problem.
Bad plug Bad coil Bad plug wire Bad valve Blown piston
Blown head gasket, burnt or bent valve, spark plug loose, busted piston, worn or broken rings,
blown piston
Increasing the pressure inside the piston cylinder would cause the piston to lower since the higher pressure pushes down on the piston.
Defective spark plug or plug wire, burnt valve, blown head gasket, fuel injector problem, or broken piston ring.