So what tests can be done to the filter to see if it is defective. I kept mine when I changed the oil two days ago.

 

Dang good question. There should be a certain amount of flow capability, but how do we rig it up to test it? I could see a piece of pipe (1/2"? - have to check) with a container overhead filled with used motor oil, and time the drainage. But then there is bypass pressure, and backflow prevention. I'm thinking you could tell a lot with low pressure air with the filter still wet from use.

 

I don't think you can judge the Amsoil based on one event. Any oil, if the temp got up over where is should for example, will lose its protection. I have used Amsoil and Mobil 1. Frankly, I think both work fine in my motor. I find that the Amsoil gear oil really makes my tranny shift more "snick-snick" than "clunk-clunk" once it warms. I use Formula + in the primary. I actually may try Shockproof but agree that Amsoil is one of the quality oils. Given that you buy 3 or 4 quarts separate, I can't see them being bad - likely a temperature spike that would hvae killed any oil...

S

 

I have been reading all your responses, while trying to do some research on my own. I have looked at oil comparison tests and oil filter comparison tests. All say the oil and filter I was running should not have been the problem as both are noted as good products.

The one thing I have been looking at is how oil filter manufacturers build in a back flow valve to prevent impurities from going back into the oil after they have passed filtering. They all use a rubber valve for this. Some are black rubber and some are of a different color. For instance K&N (what I use) uses a black rubber for their motorcycles but, uses an orange color rubber for automobile filters. We also know the many different synthetic oil manufactures use different additives in their oil or they would all be made by the same manufacture. Of course they all claim they are the best.

The K&N oil filter I run uses a black rubber back flow valve preventer as do many others.

Questions:

1. Was it a possible breakdown of this black rubber valve due to the oil additives in AMSOIL, along with the high heat that caused my oil to turn black?

2. Was this oil filter with the black rubber valve built with an old or defective rubber part?

3. If the rubber backflow preventer valve was defective, how do we explain no rubber particles were in the engine oil or filter at teardown inspection?

I have used K&N oil filters for years with no problems and Amsoil for 2 years with also no problems. While I have moved on to a different oil, I am reluctant to switch to a different oil filter. I am going to monitor my new oil change (Redline) and look for any abnormal changes in color as I put on the miles. I have no answers at this time and by all the responses, all any of us can do is theorize at this point.

 

In my case I am looking at the tempurature drop of almost 40 degrees. That would have nothing to do with the filter. Thanks for starting this thread Dave it has been very helpful to me.
Gary

 

WHAT dropped your temp 40 degrees?

 

There are at most two valves on an oil filter; and anti drain back valve and a bypass valve. Depending on the orientation and location of the filter it may not have an anti drain back valve. Failure of the bypass valve would cause a majority of the oil to bypass the filter. These are usually made of nitrile or silicon of varying colors, nitrile tends to be black and silicon usually not black. I can understand the oil being a little black if the bypass valve fails and is not filtering out the particulate. But I cannot understand this causing a total breakdown of the viscosity. The additive package/oil will usually only breakdown from extreme heat greater than 300-350 degrees F for a while or excessive dilution usually from fuel on a harley since there is no water cooling or the excessive buildup of moisture from condensation. This moisture mixes with certain blowby components to form acids that cause the Total Base Number to go down. TBN usually starts in the range of 12-14 and the oil is considered at max life when the TBN reaches 1. So I am struggling with how the faulty filter scenario would cause a breakdown in the viscosity. It would be very interesting to see the UOA on the oil in question and look at the numbers, especially TBN, viscosity and particulate content.

Hope to hear more from Amsoil and others. Very interesting stuff.

 

He shut the engine off!

 

Dave,
Don't know about the Amsoil in a HD but i bought a 2004 Chevy 2500HD that had used Amsoil syn since it was new...first oil pump was replaced by warranty at 32000 miles and i had one put on at 106000 miles...when the GM mechanic took the oil pan off it looked like it had never been changed..previous owner stated he changed every 5000 miles... Just saying, i WILL NOT use Amsoil . no even in my lawn mower.....

 

Redline seems to have the oil fad going right now. I know they have great gear oil. I was told by a mechanic that any synthetic oil in a modern Harley causes piston slap; something to do with it not sticking as well as dino oil to metal parts, and not filling the larger tolerances in a Harley motor.