i have 2 questions.
question1
i replaced the thermostat 2 weeks ago on my car after i noticed the hose was not hot after driving all day and the car was running very sluggish. That seemed to solved the problem for about a week. I notice yesterday it was driving sluggish again. i checked the hose and it wasn't hot. Could the thermostat be bad this soon? Or is something else going on?
question2
smoke coming out tail exhaust and burning alot of oil so i had the valve stems replaced. still smoking and burning oil! is there something else going on?

 

How about plugged tubes in the radiator? How clean was the antifreeze? How clean was the inside of the T-stat housing?

 

antifreeze was very clean and the thermostat housing. what do you mean plug tubes in the radiator?
i added 4qts of oil yesterday and changed the thermostat again. i had to add 3 more qts of oil but the thermostat is working as of now.

 

Hang on, if I'm reading this correct. Seven qts of oil in two days? I'd do a compression test. Sluggish, I'd bet the plugs fowled with oil. You are sure it is not leaking, but burning the oil.

 

The internal water passageways inside the radiator can get obstructed with scale & crud. Since the inside of the thermostat housing was very clean, this is less likely to be a problem.

Maybe something is visible in the radiator cap? Whenever I drain the antifreeze or open the T-stat, I try to look around as best I can inside the hoses & inside the radiator.

SEVEN QUARTS IN TWO DAYS? That's an outragous amount of oil. Keep looking to figure this out.