Do NOT start your engine every two weeks and just let it idle, even high idle.
All you are doing is adding moisture to the crankcase.
If you start it, drive it at least 25 highway miles-- enough to get the oil, not just coolant up to operating temperature.
This advice is from both Caterpillar Corp and Cummins Corp. Has not changed-- has always been this way.
And, yes, with 2007 and newer engines, idling clogs up the DPF (Diesel Particulate Filter). They are much more sensitive to long periods of idling than previous engines. Doesn't matter what engine brand.