Odd LS2 experience Valve rattle ?
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Drifting
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From: Atlanta - - - - - Save the manuals
SWAG === bad anti drain back in the oil filter ?? If seen reports of some of them being quite cheaply made in some oil filters.
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An anti drain back valve keeps the oil from draining out of the filter when the engine is shut off therefore, on startups, there is almost immediate oil pressure. Hence, when putting on a new filter, add oil to the filter. But, getting back to the anti drain back valve why would oil 'drain' from the filter when the engine is shut off? Is there a vacuum that would pull the oil from the filter back into the pan?
Just curious...
Drifting
Joined: Sep 2014
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From: Atlanta - - - - - Save the manuals
Help me out here...
An anti drain back valve keeps the oil from draining out of the filter when the engine is shut off therefore, on startups, there is almost immediate oil pressure. Hence, when putting on a new filter, add oil to the filter. But, getting back to the anti drain back valve why would oil 'drain' from the filter when the engine is shut off? Is there a vacuum that would pull the oil from the filter back into the pan?
Just curious...
An anti drain back valve keeps the oil from draining out of the filter when the engine is shut off therefore, on startups, there is almost immediate oil pressure. Hence, when putting on a new filter, add oil to the filter. But, getting back to the anti drain back valve why would oil 'drain' from the filter when the engine is shut off? Is there a vacuum that would pull the oil from the filter back into the pan?
Just curious...
I'm glad you asked because I didn't know for sure either. All I know is that the rubber flap just inside the screw end of the oil filter is a drain back valve. So I looked it up.
Here's what I found:
The membrane covers the holes where the oil gets through to the filter media and protects against the backflow after the engine is turned off. As the filter ages, the heat and the contaminated oil can cause the anti-drain back valve to harden.
Or explained in exceptional detail: VIDEO: WHY DO OIL FILTERS HAVE ANTI-DRAIN BACK VALVES?
Last edited by Dutch08; Aug 17, 2021 at 02:45 PM.
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Very interesting, I wonder if the Bosch filter I was using had a flaw or something else in the filter ? Same oil, so I kinda have to rule that out ?
