a little while back i noticed black gunky stuff when checking the coolant level. now i know that's a good sign of having a bad head gasket but I have no money or time to get it fixed right now. Also, there seems to be coolant leaking onto the exhaust because i can hear drips being burned if i pop the hood and also i can smell it in the cabin if i turn the heater on. BUT, i haven't noticed any difference in how the car drives. still seems to accelerate and cruise just fine. Could something else be causing the issues? Im just driving it real easy for now, trying to keep it under 2500 rpm. its a 89 5 speed 2.0si.