Noticeable oil loss after towing. Retorque your head. Piers Harry advised me to do this and it cured my problem. I'll bet a lot of people don't know who Piers Harry is. Boost goes up, lifts head enough to pressurize crankcase and kicks out the oil.
he used to own pdr diesel. very helpful.
hard cold start seems like **** batterys or a large draw on them when trying to start. also would change ofv