I have a 2001 F 250 PSD 7.3 with 217K miles. I run Amsoil 15W 40 HD diesel with a 2 filter bypass system. I routinely pull oil samples and have analyzed. I recently pulled a sample with 4K miles and when I received results back, it showed high oxidation but everything else was within norms. I do not have an oil temp guage yet. I have noticed that the factory oil pressure guage is running a bit higher than I am used to seeing. Everything else is normal, EGT Trans temp, water temp and appears to be running fine. I was told by Oil Analyzers that oxidation comes from high temps. Unless I am mistaking hot oil would cause a lower oil pressure. Engine is pretty much stock. Banks Exhaust, Big Head and compressor wheel. HPX and FRx and Ford AIS intake.
Anyone experienced something like this?