Skippydiesel
Well-Known Member
- Joined
- Nov 29, 2020
- Threads
- 13
- Messages
- 275
Hi Grumpy Cat,
Strikes me that efficacy of non return valve will depend on;
"2000 Toyota Avalon filter is mounted 45° down yet most all oil gets sucked out overnight in spite of the anti-drainback valve."
Interesting observations. How do you know? Have you remover filters at, say ,1 minute intervals, to check for retained oil quantity?
In the days before non return valves - on engine start up, you were supposed to wait (before revving/loading the engine) until oil pressure reached a desired level, indicating system full/circulating. In some engines this could take many seconds (especially those with many kilometers/hours) during which bearings/bushes may be running dry.
In modern engine the oil pressure no longer warrants a gauge, all that you get is a warning light, if pressure lost/not achieved. The only time you might see this light, is before engine start and after an oil change. The latter only showing for a brief moment or two, IF the mechanic has done a good job.
My Ford Ranger has a non return valve in the oil circulation system - not in the oil filter (as did my MB, 300D, W123), however all my other engines have the valve in the filter.
Strikes me that efficacy of non return valve will depend on;
- Quality of filter
- Column of oil above/below filter, providing additional sealing pressure (absent when you remove filter & allow to drain on side)
"2000 Toyota Avalon filter is mounted 45° down yet most all oil gets sucked out overnight in spite of the anti-drainback valve."
Interesting observations. How do you know? Have you remover filters at, say ,1 minute intervals, to check for retained oil quantity?
In the days before non return valves - on engine start up, you were supposed to wait (before revving/loading the engine) until oil pressure reached a desired level, indicating system full/circulating. In some engines this could take many seconds (especially those with many kilometers/hours) during which bearings/bushes may be running dry.
In modern engine the oil pressure no longer warrants a gauge, all that you get is a warning light, if pressure lost/not achieved. The only time you might see this light, is before engine start and after an oil change. The latter only showing for a brief moment or two, IF the mechanic has done a good job.
My Ford Ranger has a non return valve in the oil circulation system - not in the oil filter (as did my MB, 300D, W123), however all my other engines have the valve in the filter.