Recently replaced the head gasket on my son's 89 2.3 quad 4. The car now runs great and doesn't overheat, however I have a somewhat high pitch wine or twittering sound that I'm not able to positively locate its origin. I've gone over every part the engine as well as the transmission with the old screwdriver to ear trick but can't locate its source. The sound appears to be the loudest near the rear of the intake cam box. I thought maybe that oil wasn't getting to the cam box so I took it off and opened it up but didn't see any scoring on the housing, camshaft or lifters that would suggest a oil problem. I check the oil pressure with a manual gauge on the exhaust cam box and have good steady oil pressure there. Might be a main or connecting rod bearing but the engine doesn't knock and have good steady oil pressure approximately 60 psi cold and 40 psi hot. I drained the oil and didn't see any mental particles. When I replaced the head gasket I also had to replace the cylinder head as the old one was warped rather badly. I originally thought that since the cylinder head was so badly warped that maybe the cam box was warped as well, but that wasn't the case. I might add that it's neither the power steering pump nor the serpentine belt tensioner. Nor do I believe it's coming from the timing chain or water pump area. Not sure what to do next either tear down the bottom end and actually check the bearings or try another cam box. Can anybody offer any advice here? The car runs great has good compression, good oil pressure and sounds like a frigging bird - help!!!!!!
Thanks