i have a 1994 325is. im not sure if i need a head gasket or something else. heres the info i can give. 1) car does not overheat 2) exhaust does have a sweet smel 3) i do have a coolant leak not sure if its coming from water pump or hose. 4) thermostat isnt good ( im changing that tmrw) could that be the problem? the car doesnt really run great and at dead stop it misfires very little. can anyone help me. do i need a head gasket job? something completely different? anyone have similar problem they solved before? thanks in advance.