Hello Guys.
I am working on this Astra-H Z16XEP. There is a issue at idle where the car surges/hunts. There are no fault codes stored.
The fuel trim is at -18. I assumed that there is an air leak so I did a smoke test. I did not spot any leaks on the intake side. The only thing that I suspect is the tappet/rocker cover. When I removed the oil filler cap the smoke came out freely as though the vent valve in the tappet cover was stuck open. I am not sure as to how the vent valve works so out of interest I just blocked it off and the fuel trim came down to -1.
Am I masking the fault by doing this or is the tappet cover really faulty?
Regards.
I am working on this Astra-H Z16XEP. There is a issue at idle where the car surges/hunts. There are no fault codes stored.
The fuel trim is at -18. I assumed that there is an air leak so I did a smoke test. I did not spot any leaks on the intake side. The only thing that I suspect is the tappet/rocker cover. When I removed the oil filler cap the smoke came out freely as though the vent valve in the tappet cover was stuck open. I am not sure as to how the vent valve works so out of interest I just blocked it off and the fuel trim came down to -1.
Am I masking the fault by doing this or is the tappet cover really faulty?
Regards.