Engine consuming oil and white smoke comes out when starting the engine while cold

Question

my car has been consuming oil for a while now but only recently has started to smoke when it is started while the engine is cold. I thought that maybe because I am using a synthetic oil in a high mileage car but after switching to non-synthetic one it still consumed the oil although at a slower late but still a quick one none the less. I thought it was because of my aggressive driving style and how I do late shifts and I stopped that completely and the rate of consumption didn't change much. And only recently my car has started to smoke, when I start the engine and wait a little then press a little bit of gas it smokes not a lot and the smoke stops after a short while. It has been like that for maybe 2 weeks.

I am not sure if it is worn out piston rings or something else, I also did a compression test and the results were very odd I was got 140 150 140 150 on my car which I think is really high? maybe the guy did it incorrectly as he asked me to start the car and didn't use an assistant and I didn't press the throttle wide open while the test was carried. Also he did a wet test on a single cylinder and it gave from 140 (dry) to 153. He also said the "escape" rate of the cylinders is 13 PSI something I didn't really understand, he also said that new cars get 5 PSI while really old ones get 15 PSI

I haven't noticed a difference in the car acceleration or speed, so where is the problem exactly, are the piston rings worn out? is it something else in the valves?

The oil usually lasts me about 3 to 4 weeks before I need to add more.

Answer 1

Your piston rings are worn. This is allowing oil into the combustion chamber so it's being burnt off... Typically accompanied by a sweetish smelling exhaust and heavy gas smell in oil itself.

And the reason you didn't need to step on the gas when the compression was checked is because the spark plugs shouldn't of been working... This it wouldn't have helped to add fuel... It's checking the compression of fuel and air without spark...

The compression is different for all vehicles but as a base line 120-150 psi is acceptable... The 13 psi he was referring to was that the oil coated the cylinder walls thus helping to seal the rings. This is why the boost in psi occurred. If it wouldn't have changed at all or very little it would mean the valves weren't sealing.