Would be worth doing an oil pressure test as well. I had one a few years back that drove me mad. It would be running perfect until going over 3000 rpm then it would miss on cyl 4. A cylinder leakage test didn't even show this up. I guess the valve was only very slightly held off of its seat and either turning the engine by hand or pressurising the cylinder closed it again. Went for oil pressure next and it was well over spec at higher revs. I ended up changing the oil pump on that one. Had loads of other vehicles with the start of head gasket or valve/seats burning out being picked up by the ecu before the customer had noticed.


Liam