New to me '74 Scout II with a 345. I have had 3 episodes of valve train noise. The first was shortly after I rebuilt the carb and started driving it. Took it out on the xway and got valve train noise after a couple miles at 70 mph. I'm familiar with the 'oil starvation' problem and possible remedies. The noise subsided within 10-15 seconds of slowing down.
The second time (probably about 150 miles later) I was starting and stopping the engine in the driveway, checking the trans fluid level. Had an immediate loud tick upon one startup that persisted through several more start and stops. A couple days later removed the valve cover and one rocker (forward rocker of #6) was a bit loose, but when started and stopped a few more times, it became solid again and the tick went away. Oiling of the valve train seemed fine. Oil pressure on the dash gauge (for what its worth) was fine.
The third time (about another 100 miles later) was this morning. Drove about 7 miles on the expressway at 60 mph and the tick/noise showed up again. It didn't resolve with pulling over and idling a few minutes. I pulled off and started to limp home on back roads at 20 mph, and after several miles the noise resolved for the rest of the trip home. Oil pressure was again fine according to the dash gauge.
I think the first episode was just starvation, but not the second two. Seem more like a lifter problem, or intermittent oiling problem causing a lifter problem. Can a lifter fail intermittently like this? What might be the cause of a one-head (sided) intermittent oiling problem (the noises seem isolated to the passenger side)? What other possibilities am I missing?
The second time (probably about 150 miles later) I was starting and stopping the engine in the driveway, checking the trans fluid level. Had an immediate loud tick upon one startup that persisted through several more start and stops. A couple days later removed the valve cover and one rocker (forward rocker of #6) was a bit loose, but when started and stopped a few more times, it became solid again and the tick went away. Oiling of the valve train seemed fine. Oil pressure on the dash gauge (for what its worth) was fine.
The third time (about another 100 miles later) was this morning. Drove about 7 miles on the expressway at 60 mph and the tick/noise showed up again. It didn't resolve with pulling over and idling a few minutes. I pulled off and started to limp home on back roads at 20 mph, and after several miles the noise resolved for the rest of the trip home. Oil pressure was again fine according to the dash gauge.
I think the first episode was just starvation, but not the second two. Seem more like a lifter problem, or intermittent oiling problem causing a lifter problem. Can a lifter fail intermittently like this? What might be the cause of a one-head (sided) intermittent oiling problem (the noises seem isolated to the passenger side)? What other possibilities am I missing?
