Is there a benefit to pre-filling oil filters, or am I just adding an extra bit of work? I do, as I figure that it'll put the oil into the engine quicker when the engine is dry after draining.
I always prefill my new filters but it's more a personal preference, and my filters go in straight up instead of at an angle or upside down so not much chance of spilling when I install them. One thing you should absolutely do every time is to add a thin layer of oil on the new gasket to ensure a tight seal. Never forget that step.
Engine isn't "dry" when you do oil change. Every surface that requires a film of oil has it.
A freshly rebuilt engine needs to pre-lubed with assembly lube and oil pressure established without cranking it.
@heyinway
Good point!
I seriously doubt they pre-fill them when you take your car to a shop or mechanic to have the oil changed.
For cars with the small soda can size filters, no.
If I had a big diesel with 1qt size filter, then yeah.
If you really want to get anal about it, disable the ignition and use the starter to spin it up enough to get oil distributed, then re-enable the ignition.
Big industrial engines have pre-oilers that pressurize the oil before engine start up. Never saw it on a car. Hey, if you're smart/lucky you probably don't have a stop/start engine that stops and restarts at every stoplight.
If your filter is placed sideways, I wouldn't do it. Its not worth the mess of the oil spilling everywhere. If you are a real fanatic, you can pull out the fuel pump relay and crank it over a few times. This will allow the filter to fill up without the engine actually starting. But if it is placed vertically, then why not? Pre filling it only takes a few seconds and its only beneficial.
The oil pressure will be low a fraction of a second, just the time to fill the filter. Not a major issue as some cars have the filter upside down or on the side so it can't be filled before installation.
The oil get sucked fromthe filter and for that second it car run dry with no oil in it.
How much harm it does to your engine ..I am unsure .
@klob
insignificant. How long does an oil change take? Maybe an hour at most. There's still oil on the engine parts.
I'm of the fill it type. Here's why although many good points above.
ALL MOTORS are not created equal (including oiling of said motors). So some may have more wear by not filling than others and in theory, filling will reduce oil pressure for x time.... all of which is likely not quantifiable on todays engines... but I bet there are a couplie that it does affect/is measurable ; )
Good practice, so stick with it.
