ISX and Bypass Oil Filter Systems

[Mrkentee]

(07-22-2025 )45RVLSX Wrote:  Rawze, quick question-my diesel tech was concerned about adding gear oil due to the sulfur in gear oil causing a corrosion issue. What are your thoughts about the sulfur being an issue. Full disclosure this is an ISX in a Motorhome, not an over the road truck, so maybe that makes a difference-less miles, longer time duration between changes-generally 1 per year based on typical 12-15,000 miles( I get about 7 mpg-maybe a tune would help both issues, but not sure there's a payback at my miles/yr). I'd like to do the best thing for the engine as I don't plan on replacing this motorhome in my lifetime-I'm 70 so this is my last one. My LSX typically runs around 207 degrees going down the road, does this seem ok? My LSX is a pre def unit with EGR, does a bypass make sense for this engine? Thanks for this forum, who said you can't teach an old dog new tricks!!

I’ve heard it said that every diesel engine should have a bypass filter, and I agree. But I will say the Fleetguard LF14000 NN oil filter (not sure if that works on your engine) has a built in bypass system they claim. I use both on my ISX, and my oil stays clean.

[ne14jpn]

Tech question - Can I use "Port Location #1" for bypass filter supply pressure feed line referenced from the Engine Oil Cooler picture in Post #9 of this thread?

In Post #15, Rawze mention the ability to use Port #3 or 5 for oil supply line. He had heat issues from the turbo with #3 and ended up using #5 which seems to be the most common port for supply. My issue is clearance to #5 from the turbo outlet charge air tube in my application. The chassis is a 2005 Volvo VNL 780 with the CM870 ISX and Eaton 13 speed. There is not enough room to install a -8 fitting of any sort on my truck in that location.

Port 1 is wide open so please let me know if that will provide a supply feed to the bypass filter? Thanks!

[hhow55]

. Locate a pressurized port such as a galley port, pressure sender
port, etc. AMSOIL recommends adapting off the pressurized oil
port using a fitting(s) to accept the 1/2” JIC female hose end
provided in this system. Purchase of adapters for your specific
application is required.Maybe this helps?