Originally Posted by charlie264
I doubt its the pressure release, pull the cir clip and measure the spring. Make sure you have a replacement cir-clip first...my broke, wasn't an issue as I replaced the whole thing. I'd check/replace the cam chain tensioners and springs. Measure the oil pump within spec.
I hope it helps. The oil pump was well within spec, however the old spring was considerably shorter than the new one.
So what to do about the crank bearings