pre-filling oil filters

I've done that before myself. I always pre filled the oil filter to prevent the big air bubble in the filter from going through the system. I really don't know if it helps or not but it seems extremely prudent to me to do so.

 

I fill the new oil filter ~3/4 full with oil before installing it. The point of doing this is to allow the engine to quickly build up oil pressure upon startup. If you install an empty oil filter, then the engine will have to run for a few seconds without oil pressure and you will hear a funny sound during this period.

 

i think this is a preference thing, and i don't think it will hurt or help either way...

the important thing is to lube the oil filter gasket

theres enough engine oil in the system after you drain it, that its not a problem

you would have to disassemble everything to remove all the used oil

and doesn't the prius spin the engine up to operating range rpms before the engine starts anyway?

 

I too fill my filters as well. I started doing this with my diesel truck because my oil filter hold about a quart and a half of oil and didn't want the engine to starve. I do it with my Prius now as well. The only time prefilling the oil filter manually can cause a problem is if you drop some junk down the hole... specifically, the aluminum safety seal that most oil containers have. This is a problem because whatever falls in the hole will be sucked into the engine and not be filtered... so make sure crap doesn't fall in the filter. What the shop told you was total BS. If you want to talk about air bubbles having a completely empty filter is more of a air bubble than having a 3/4 full filter.

 

john1701a says to prefill, so go ahead, heh

 

Seems odd advice since an empty filter is one giant air bubble to begin with. All the air in the filter has to be forced through the system so less = better as best I can tell.

The advice is counter to anti-drainback valves and the like.

 

Never heard the air bubble theory before. I usually pre-fill when possible, but some cars (Toyota Avalon) don't permit this. Seems to work either way.

 

I have filled vertical filters for years, both on my cars and on customer cars when I was a pro mechanic. (this doesn't work on the old Studebaker V-8 motors with the top mounted filter ... they mount upside down)

Anything like this which helps your motor get oil sooner is good ... and I would seriously question the ability of any "mechanic" who said not to do so.

"might cause an air bubble in the system..."? What kind of crap is that? Must be one of those signs of the times where some people are getting dumber every day.