The problem started when the check engine light turned on. It was burning oil for the whole time but not much I think maybe lees than now. At first I thought that catalytic system is blocked and I started adding some fluids to gas. But now the coolant started disappearing and the fumes started to smell chemical. When I hit the gas it’s going much slower than before. When I take my foot of the gas slowly it starts to gain speed. So on full gas it’s going slower than on half. When the car has less than 3k revs and I hit gas it’s going like nothing. But when it’s 4k or more it gains speed faster. The car shakes jerks every time on 4 gear 2k revs and full gas. My mechanic said after checking that the head gasket is okey but I asked what’s he problem and there is oil in new coolant. And he said it’s micro crack in the gasket so sell it fast. But I really like these car and it has check engine light so selling will be hard. Is my mechanic right or it can be something different. Pls help and if he is right what should I do or how to sell it without the check engine