UOA and bypass filters?

[JBJ]

I posted the following to the Bypass filter board for those folks to answer. However, the UOA people might know better? Here it is:

How does a bypass (finest filtration bypass, for this question) filter affect oil analysis?

I don't mean to ask if the engine wear will be less, I mean to ask will the bypass filter filter out very fine particles, water, antifreeze, or any other substance that is actually happening in a vehicle which would otherwise be caught in oil analysis?

Or to put it another way:

If I run my '93 Dodge diesel for 5K miles, get the oil all nice and black and contaminated. Then....

One sample of the oil, as is, is bottled for testing.

Then...

The rest of the oil is run a few times through the best and finest bypass filter (TP?) setup. A second sample is then taken of the "super filtered" oil and sent in.

What are the possibilities for different test results?

If I was having high iron or bearing wear, or antifreeze in the oil, could a very efficient bypass filter cover up this problem?

Thoughtful responses will be very much appreciated.

(the great thing about BITOG is the high number of quality responses!)

Thanks

 

[olympic]

This has been debated here a few times and no one really knows for sure. It's concievable that a really good bypass filter could filter out wear particles and absorb water and antifreeze.

As for antifreeze though, it's usually accompanied by a spike in sodium and potassium in the UOA which wont get filtered out. We've had examples posted here before that showed elevalted levels of these elements but the sample tested negative for glycol, even without a bypass filter. So there should be no worries about a bypass filter masking a coolant leak.

 

[Pablo]

I don't think we've seen enough REAL data, from controlled tests, to come to a conclusion.

I mean some of the filters are rather large, add over a qt of oil.....so you would think just by volume alone they would improve a used oil analysis. But it's just not that clear.

It all points to the usual: In typical $20 used oil analysis we can spot a great used oil analysis, we can spot a defective engine in a used oil analysis, but we have difficulties attributing or accounting for system changes.

 

[youngbuck]

I am considering getting a by-pass filter (Amsoil, dual remote setup), but I am wondering if it is really worth it if I plan on changing my oil at regular intervals w/ good synthetic anyway.

 

[Dick in Falls Church]

If your mind is set to change the oil every 3 to 5,000 miles, using a good synthetic, then the Bypass filter is probably overkill.

If you use oil analysis to determine the frequency of change, then the bypass filter probably makes sense. If you own a diesel, then it makes a lot of sense. If you run a fleet, or have commercial usage (lots of hours/miles), then it probably makes a lot of sense.

 

[Jim 5]

I am considering adding a motorguard bypass to my 1/2 ton truck. I don't need it but think it might be a fun project.

If I do that, I'll do so at the end of an OCI and run this test for you with a before and after UOA on the same oil.

 

[Shaman]

I think the only way to truly test this would be with an offline filter setup. Dump 2 qts of oil into a bucket, take a used oil analysis from that fluid, then, run the fluid through the filter with a pump for however long you want to(overnight?), then send in the other used oil analysis, or, send them at the same time, specifying which is which.

 

[oil&coffee]

I have a 2004 cummins - am to use somekind of syn. oil.. and am to use the oilguard bypass and change it out when I change the oil at maybe 2x the interval.. the oilguard filters are only $13..

 

[LACTD]

Thats about what I do. Once a year with full flow at 5,000 miles. It saves 22 quarts per year!

 

[youngbuck]

I am going to bump this thread to see if we can further the discussion. Very interesting topic. I've been wondering the same thing.