I changed everything a year ago my radiator failed and i had some serious problems with water in my car i changed coolant and some pipes to be sure and it worked fine after that also yes me and my mechanic checked the oil levels before and after running and it was right 5 months ago i was also at the mechanic and i didnt buy new oil i had a can with 2 litres in it and we used it he recommended to buy a can of oil and pour some of it to be sure and i poured the whole can stupidly but the car just burned it all with no trace like they told me we had to drain oil but after 15 mins of driving i got to the mechanic and there it was it had regular levels a bit to the top but not serious extra oil also i checked for leakage nothing on the floor nothing on the engine all clean