"John Horner" wrote in message
news:YOX2j.9957$Mr.1352@trnddc04...
B A R R Y wrote:
John Horner wrote:

It is called an anti-drainback valve and most oil filter incorporate
one. Without it your engine would take longer to build oil pressure at
start up, which is a bad thing.


The valve is not present in the correct Toyota oil filter.


Not according to Toyota!

"An anti-drainback valve, which prevents oil from draining out of the
engine and into the oil pan, helping to protect your engine from increased
wear during cold starts."

http://www.toyota.com/html/shop/deal...ilfilters.html


I think that feature is a general one that does not apply to all filters on
all vehicles. Not all same brand filters operate the same. If genuine
Toyota top located filters empty out there would be no check valve
preventing this.
Besides that, the statement is probably worded wrong. I do not know of a
common automotive engine that oil does not naturally flow from the engine
into the oil pan during operation. The oil goes into the filter before
returning to the engine. They probably meant to say that some filters check
valves prevent oil from draining from the filter back into the oil pan. The
filter does take some time to refill if empty.