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- Plano, Texas, USA
I don’t have a Mazda “Value” oil filter in hand, but it doesn’t have the anti-drainback valve either if I remember it correctly. From the pictures cz5gt posted above, that little something at the bottom of the canister is the by-pass valve. Since it’s a cost-cutting “value” oil filter, I don’t believe Mazda would spend an extra 1¢ to have a unnecessary anti-drainback valve in there.So the "value" type filter with the louvered punched holes appears to have an anti-drainback valve under the base-plate inside the filter.
The premium Mazda Thailand filter has no anti-drainback valve present.
Does this Mazda CX5 oilpump and plumbing is designed such that anti-drainback is un-necessary, and anti-drainback functionality is somewhere else in the lube system?
Before this 2015 CX5, my home fleet included a Toyota 22RE, and depending on the filter I used - Fram was the worst - a hot restart 10 minutes after shutdown would get three or four "knocks" on startup before oil got to whatever was knocking. And when I shut down and did an oil change, the filter was always mostly empty. Wix filters did not knock on a hot-start, and were full when removed for oil change. Cold startups required a few seconds of crank for the fuel injection to initialize and inject, so cold startups never "knocked". So the anti-drainback valve in the filter does something on a 22RE Toyota.
Given the absence of anti-drainback valve on the Mazda-supplied Thailand filter, it appears the anti-drainback valve built into the filter would be extraneous.
The oil filters used on Mazda’s SkyActiv-G engines, the 2.5L and the 2.5T, don’t need any anti-drainback function is because it’s installed vertically with the opening up. The oil inside the canister won’t go anywhere when the oil circulation is stopped. The oil supply will be there from the oil filter once the engine starts.
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