Bypass filter post-install question... - Diesel Forum

adephue · 03-09-2007, 09:00 PM

Today I successfully installed an Amsoil BMK-11 Bypass filter on my truck (see sig). The install was a piece of cake! Many thanks to cdnsarguy whose photo of the location of an oil system plug made the entire install painless. I did the install with my current oil in the pan (about 500 miles on Rotella T 15w40) just to make sure that the whole setup wasn't going to rob me of too much oil pressure, at which point I would have sold the unit. I didn't want to spend the money on 13 quarts of synthetic if I felt the engine was being starved by the bypass unit. I primed the bypass filter with new Rotella T, fired up the engine, and within seconds had a small stream of oil filtering down into the oil filler neck from the bypass unit... no noticeable change on the oil pressure gauge in the dash.

My question is... is there any benefit to letting the Rotella T run until it is time for the next change? Am I wasting the benefits of the setup because I am not using pure synthetic? Or will the bypass setup still have a positive effect even with regular dino oil?

cdnsarguy · 03-09-2007, 10:24 PM

Can't remember if I asked you.....

Do you have an actual oil pressure with numbers guage or the "feel good" needle from Ford, the one from Ford operates at 7PSI.

I would think any extra filtering is accomplishing something...

arthurgoboom · 03-10-2007, 01:05 AM

Bypass filtering will help even on conventional oil. The advantage of the synthetic oil is usually a better level of protection (depends on brand), improved viscosity stability (doesn't thin as much when oil gets hot), and less volatility (does not evaporate light molecules off and result in thickening oil over time). Notice none of that has anything to do with contaminants in the oil. Filtering is there to remove the contaminants, so your small micron bypass filter is helpful no matter what oil you run. Congrats!

adephue · 03-10-2007, 02:29 AM

I have the feel good gauge. Should I get another one? If so, can I grab one at a local auto parts store? Perhaps I should install a T fitting and plug the top opening on the T, that way I can do a pressure check or get a sample... just thinking out loud. If I do grab a gauge, where should my numbers run for my pressure to be adequate?

cdnsarguy · 03-10-2007, 11:33 AM

I used the shop SnapOn oil pressure guage to check mine, then installed a new sensor and I am happy with its performance and reading on the feel good guage. I have driven for 50 years with feel good Ford guages with no regrets. If I was to place a direct reading numbers guage anywhere, I would put mine in the engine bay. Only because I hate clutering up the dash and I like my eyes on the road. Also any oil leaks stay out of the cab.

Oil pressure at hot idle:
min 10 psi
at 3000 or above 40-70 psi.
Guage/sensor reads good oil pressure at 7 psi.

Visit my gallery for the oil system pic.......

RLDSL · 03-10-2007, 06:00 PM

All big trucks have bypass filters from the factory, they have for years. That's what allows them to go 12-15000 miles between changes on regular oil, so yes, you will be fine leaving that regular dino oil in there for a while. In a few days it will be very clean. Remember to replace both filters when you change.

-----Robert