I have a oil pan heater on my 6.0 which I use when I KNOW I will be starting my truck in colder temps (and it works great) but I don't always know when I will be needing my truck so I find myself starting it unplugged from time to time. My question to others that have these engines is (in your opinion) what do you consider too cold to be starting without plugging in for awhile first? and what harm, if any do you feel is being done to the engine if it is started at say 10*below zero without the benefit of an engine heater? other than the obvious slower oil pressure build? Thanks for your input.

 

I would probably consider plugging in if I saw sustained -15 or below.

I never plug in here in Northern Colorado.

Josh

 

If you're running 5w40 synthetic I don't think you're hurting the engine at all. The flow and lubrication properties are so much better now than many years ago. I can't say it's the healthiest thing in the world, but you're not shaving years off your motor either.....

 

I would say the biggest consideration is the batteries/charging system. Battery power (amps) drop quickly when the temps go way down. The engine is a bit harder to turn over so the starter requires more power than usual, not a good combination. Add to that the glow plug cycle will be longer (wait to start and after start), we'll probably flip on the defrost before we walk away, and flip on the seat heaters if equipped, and now things are in a much bigger "bind" than a start on a 70*f day. It will recover if driven long enough, but it was still a moderately traumatic cycle for the batteries and charging system.

 

Thanks Guys, all good points, and like I said I will be plugging it in on most cold nights and every cold night that I KNOW I'll be starting it the next morning. I started it this morning unplugged at 17* above zero and it fired right up without so much as aflutter and after a couple the high idle mode kicked the RPMs up to around 1000 and life was good. That being said I am not one to tempt fate and push it just to see how cold it will get before it won't start. Thanks again for the advice.