Oil Filters

[Forspeedrs]

1. Opinions of pre-filling the oil filter during an oil change, (obviously where applicable, such as a vertical mount). I’m from the school of filling the filter before installing it, since I learned that way, and intuitively it makes sense. Recently an engineer friend of mine argued not to do that as you potentially create pressure against the anti-drain back gasket, which would not allow initial oil flow into the filter, causing a momentary starvation. To me, I think it’s bogus, wouldn't any excess "air pressure" diffuse through the filter? Any thoughts?

2. Fram Oil Filters... some big name professional race engine builders SWARE by them, others cringe at their use, claiming horror stories of collapsed filters.. and hence engine failure. Opinions...

 

[SMOKEY44211]

A few years ago I did an evaluation of oil quality at 1,000 mile intervals. The first 1,000 mile check always showed the highest accumulation of particulate matter vs subsequent readings. Also tested prefill vs dry filter instalation. Result was significant reduction in particle count using the prefill method. Regarding Fram filters I use them and they seem up to the task. In the 30+ years that I've used them haven't seen any engine failures that can be attributed to the filter. That being said I think there are superior products available from other manufacturers. Micron sizing, element area, guage of material and overall construction quality (cost being no object) may tip the scales in favor of some of the other offerings.-------Phil

 

[aspearin1]

Prefilling the filter will ensure that oil is in contact with the filter media, (i.e. no air bubbles). Since you are not filtering air, you are making no use of whatever media is in contact with the air. This will cause premature filter plugging. Also, since air is compressible, a back pressure situation will actually pressurize the oil filter. Once the pump is turned off, an obstruction is removed, etc, the there could be a sudded pressure release... of perhaps hot oil.

Aaron A. Spearin
ASQ CSSBB
Engineering Six-S'$

http://www.Engineering6ss.com

"The only constant in life is change." -Bruce Lee

 

[RossABQ]

Aaron, There is no air in the filter once the system is under full pressure. All the media is used for oil filtering. If this were not true, a filter installed dry would still be dry when (maybe five minutes later) the filter was removed during a rebuild of the engine.

There are some vehicles that the mfr. recommends dry installation. Honda or Mitsubishi, I don't remember which. On these vehicles, a full filter somehow prevents the pump picking up prime? Sounds bizarre, but "I read it on the internet". I do know for sure that remote filter setups (aftermarket) for certain engines are adamant about dry installation.

Personally I always pre-fill. And I quit using Fram after I read several extensive tests on the 'net. Wix is the affordable quality filter; NAPA filters are made by Wix and are a buck or two more than Fram.

 

[aspearin1]

I dont' prefill. I have a Saturn SL1, and the assembly intallation is at an downward angle, (with me underneath). I don't see anyway that air can be vented in this design. Hopfully they just build extra room in the filter to make up for it. So long as the media wets slower than the oil can flow I will fill the majority of my upstream filter housing. I'll look into switching away from the FRAM. To improve engine life, there are also some articles out there that suggest new engine oil should be filtered prior to putting it in the car, all-together. There are also some schools of thought that "oil" does not need changing, only "oil filters." The SAE experts in these forums will probably disagree with this, but I hear it's a common practice for large fleet vehicles.

Aaron A. Spearin
ASQ CSSBB
Engineering Six-S'$

http://www.Engineering6ss.com

"The only constant in life is change." -Bruce Lee

 

[RossABQ]

Interesting; I have an SC2 (same engine, DOHC vs SOHC), the filter is horizontal and I can only prefill about halfway without losing some.

I think the fleet practices you are describing are to allow extended intervals, but do not replace regular changes.

 

[Ataloss]

It's only one data point, but I've always used Fram filters in my 1999 Cougar (or the very inexpensive but mechanically identical Honeywell filters when available) and have never had any kind of oil related failure. This car has >300,000kms with 8000-10000km oil changes with the cheapest 5W30 oil I can find.

I figure if Fram oil filters were so horrible, there would huge amounts of engine failures, especially since so many 'quick lube' oil change places use Fram filters.

Bob

 

[MechanicalChef]

I group cheap oil-filters with cheap condoms.

They'll probably work equally as well as higher-priced models. But if it's costing me $2 extra every 3000 or so miles, I'll buy something that doesn't cheap out as much as Fram on construction.

 

[drwebb]

"I hear it's a common practice for large fleet vehicles"

Large fleet vehicles have comparatively large oil sumps. Fit an auxillary 50 gallon oil tank in your car's trunk and it's true you likely won't have to ever change the oil again. Diesels also have to cope with high soot loading- especially with EGR- and the filter changes are adjusted accordingly.

Those 'schools' should be careful about drawing analogies between applications they apparently don't fully understand.

 

[TheBlacksmith]

And oil, while it doesn't wear out, can slowly accumulate contminants too fine to filter out with a full flow oil filter and the anti acid additives, etc. get used up. Those big fleets almost always use oil analysis to determine when to change the oil. For 90% of the people today, every 3000 miles is too often, never is not often enough and whether or not you prefill the filter won't matter an iota in 200,000+ miles. Unless your oil pump is dying, it's going to fill the filter in under 10 seconds of unloaded engine idling. If your filter is larger than your oil sump or you routinely run the engine up to 5000 RPM in gear as you start it after a filter replacement it's all personal preference.

 

[Lou Scannon]

Blacksmith, agree wholeheartedly!