Recently started running WMO in my 6.9 IDI. Truck ran like a top here for a while, but recently it started surging. I only put oil in the rear tank at about a 50/50 mix. While driving, the engine will randomly accelerate about 500 RPM before dropping back down, even on cruise. Switching to the front tank with pure diesel in it will solve the problem. I had originally thought that my WMO mix was too high, so I added some more diesel to the rear tank; to no avail. Some people say it sounds like air intrusion or a clogged filter, but I'd imagine that would have the same surging problem for both tanks right?
Any ideas on what I should check for / look for? Thanks!
Any ideas on what I should check for / look for? Thanks!