All Small Six start up rattle

[comet6]

My daily driver 250 has 85k miles. This week it developed valvetrain rattle upon startup in the morning. Fl1A oil filter. Maybe drainback valve leaking ? Oil is is very clean.

 

[drag-200stang]

Sometimes an exhaust leak can sound like a lifter tick.

 

[comet6]

this goes away in 5 seconds or less

 

[PSIG]

Could be leak-down in any portion of the oil system, from the drainback valve to the lifters, or the pump, or air added at shutdown with low oil level or foaming. Assuming it's a drainback or leak-down issue, or air in the system, a 10-second run with shutdown and restart would verify this (no rattle 2nd start). A filter change would (by probability) confirm if it's there. Disabling fuel/ignition for extended cranking to prime oil before start would confirm if it's in the lifters or pump. Measuring rocker/valve height on shutdown versus after overnight would point at the lifters, or intermittent would indicate specific lifters, and so on. One workaround if air/drainback could be a pre-oiler, pretty cheap with a fire extinguisher or propane body and a valve.

I had a similar one recently in a turbo-Diesel, and it was the filter valve, although it didn't completely solve the issue. I'm running some flush in the oil next week to see if a little cleaning helps the lifters. Yeah, it's pot-shot, but I'm not going inside the engine on this one. I may do a pre-oiler this summer just to ease my irritation LOL.

 

[48 F3 Joe]

Could be leak-down in any portion of the oil system, from the drainback valve to the lifters, or the pump, or air added at shutdown with low oil level or foaming. Assuming it's a drainback or leak-down issue, or air in the system, a 10-second run with shutdown and restart would verify this (no rattle 2nd start). A filter change would (by probability) confirm if it's there. Disabling fuel/ignition for extended cranking to prime oil before start would confirm if it's in the lifters or pump. Measuring rocker/valve height on shutdown versus after overnight would point at the lifters, or intermittent would indicate specific lifters, and so on. One workaround if air/drainback could be a pre-oiler, pretty cheap with a fire extinguisher or propane body and a valve.

I had a similar one recently in a turbo-Diesel, and it was the filter valve, although it didn't completely solve the issue. I'm running some flush in the oil next week to see if a little cleaning helps the lifters. Yeah, it's pot-shot, but I'm not going inside the engine on this one. I may do a pre-oiler this summer just to ease my irritation LOL.

When I worked in the Ford store in the 70's and 80's Ford considered it normal for lifter tick for 5-10 seconds on cold start up. We only saw this issue on cruddy engines. Change the filter first.

Joe