Forgive me for asking this, as I'm sure it has been covered before in other threads. I just wanted a thread specifically for this to get a more definitive answer than those I've seen before...

Question: When changing oil and installing a new filter, is it truly necessary to fill the filter with oil before installing it (as opposed to installing it dry)?

My gut feeling/experience says that this is an absolutely necessary step; however, it seems to be often overlooked, and most people I've asked act like it's not that important/optional.

I just recently installed a dry Delco "truck" oil filter on my L98, and I noticed that the oil pressure was at zero for like the first 4 (or so) full seconds after restarting the engine, after which it finally shot up. I know that was directly a result of not filling the filter (and I expected as much), but now I'm starting to wonder if those few seconds do more long-term damage than I had previously thought.

 

Well, of the several engines I have to maintain my Camaro is the only one that you can put the filter on in its upright position, so that's the only one I can fill with oil. All the others (wife's Honda and a couple of F*rds) go on sideways and, well, just try to put one of those on with it full of oil. I've even tried just putting a little bit of oil in them but it always runs out, usually in my eyes so I just stopped doing it. One of the F*rds has 211,000 miles, the other has 183,000, both still going strong and they have always been started with a dry filter after an oil change. My opinion is that it doesn't matter, but hey, I could be wrong.

 

Yeah I didn't think about sideways filters--The V6 f-bodies also have sideways filters.

The bottom line is, though, that all the time spent filling the empty filter with oil is time that the engine is running with no oil pressure. I guess the question, then, is whether that 4 or so seconds (depending on the size of your filter) without oil pressure is enough time to damage the engine.

 

install dry, there is enough lube on the parts still to protect them from any noticable wear. the only filter i ever had to pre fil was a feul filter for deisel engines. it realy does not matter if the oil filter is dry if your conserned about running engine with low pressure disconect the ign wire and crank the engine till prerssure somes up then reinstall the ing wire.

 

are you capable of measuring that amount of wear that is caused by the dry startup? no.


but the lack of oil pressure on EVERY startup is why "startup is when engine wear is at its worse" lol.


if you can, do it. it does help.

if the engine has to startup dry because its sideways, run the engine for a little while before changing the oil. that way a nice coating is on the parts before you start it. if you let it sit for the night, then change it without starting it, it'll cause more wear.


still... its not a measurable amount until you do it 100s of times.



so yea filling the filter is somthing simple and helpful that the home guy can do. but dont expect every tom-dick-harry and mechanic do do it when they change oil.

 

If its one of the big truck filters prefill it. Doesnt take long and minimizes teh time the engine has to go without oil.

 

Go to 99% of shops/quick lubes and see what they do. They just stick the filter on. Why should they care what happens to your car? They dont. Then ask them what they do for their own car (assuming they care about it) - the answer - they try to get as much oil in the filter while installing it, whether its verticle or horizontal. If your good at spinning on the filter, very little is spilled. I always fill the filter first on my cars.

 

Of course you can't always fill every filter with oil before putting it on, but I do believe you can minimize any damage done by putting one on dry by simply cranking the engine over and as soon as it starts, shut it off. Keep cranking and shutting off until you see oil pressure on the gauge. My brother in law taught me this, and I fully believe it works. This will keep the actual running time without oil pressure at a bare minimum. You could even unhook the coil wire or the hot wire on an HEI and just crank the engine over until you see oil pressure. It seems like a small amount of inconvience for peace of mind, especially if you just put a lot of blood, sweat, tears, and Ben Franklins into your new pride and joy. And IMHO, even a lowly Geo Metro doesn't deserve an oil change at Jiffy Lube, etc.

 

OK, but while you are cranking the engine, gasoline is being introduced to the cylinders. If it doesn't ignite, it washes what oil there is off the cylinder walls, accelerating wear in the cylinders. I've racked up 230,000 miles or so on a 3.1 v6, and never even considered trying to fill the filter first. Just spin the filteron, fill the crankcase, start the motor and be on with the rest of your life...
My two cents,
Tim sends

 

Amen to that. Filling the filter may give you that warm and fuzzy feeling, but with that feeling and a couple of quarters you can make a phone call. Thats about all its worth.

 

:werd:

 

I always fill the filter. May not help, but it cant hurt.

 

ok I can add to this topic. I work at a quick lube place and there are only two types of vechiles that need the filter primed (filled prior to being put on) that is diesels and cars with super chargers (i.e. grand prix gtp, bonnevile ssei). its not so much the motor needs the oil right away as it is the trubo/superchager that need oil asap. the motor is turning about 900 rpm at idle, that sould like alot but when you consider a turbo is turning at probabbly 4000 rpm.

 

I had a car that wouldnt do well without prefilling the filter as much as possible. Was a 3300 and dont know what clearence issues it may have had but it would have a hard time iding for the first few seconds untill it filled the new filter with oil and got it circulating.

 

My opinion, fill up the filter. It isn't that hard to do, and while it may not make a huge difference, it does make a difference. Talked to a mechanic on a NASCAR team, they won't start the engine unless the oil pump has been primed for like 20 minutes!!! Only reason for doing it so long is they want the oil at operating temp for initial startup. Not sure why........ Anyways, it is an easy way to make your engine last longer "unmeasureably longer", but still longer.

 

all of the eaton based OEM blower cars have self contained oiling systems. its the turbo cars that need the oil pressure, not the superchared ones.

 

I have seen a turbo or two munched by lack of oil. It's still not that noticeable of a loss of oil.