My oldy has some issue again. The engine is hard to pass 2000RPM and engine sound loud but not squealing or Knocking.
There was also some smell of burn engine oil...Can it be bad spark plug or something else? Thanks
Most likely you can also smell coolant coming out of the tail pipe when the engine is running. That is assuming you are using coolant and not water, because there is of course always water coming out of the tailpipe.