this will be the first winter ive had my duramax up here in the michigan cold
just wondering how they fare in the sub freezing starts?

my 6.5 barely started and now that it is older wont start if i forget to plug in the block heater on the bad days.

how are your dmax's doing in the winter?

anyone use a block heater anymore?


i felt some 60degree days last week now im alredy thinking winter in august...lol :help:

They do great. Some use synthetic 5w-40 in the winter time to help with starting. Mine has a different glow plug system than yours and mine started right up at -12*F. I have read the LB7 have no issues either.

mine started great at -50 last winter. I did have it plugged in, running delvac 1 5w-40. Of course when it was that cold, I didn't get much heat, but I didn't expect too much. That's why I had aftermarket heated seats added. I also did the high idle mod. It works pretty good.

The Dmax's will start as well or better than any other diesel out there in my opinion. I like to use an oil pan heater whenever possible, but on a ski trip last year I didn't have access to any power overnight. So, I woke up to a foot of fresh powder and -12 F. Truck started like a champ!

The 6.5s I've been around would hesitate to start if it was even below freezing!

As mentioned use synthetic and a block heater if a plug is available in temps colder than 0 deg f. This helps to reduce friction in the cold engine. They will start with no problem below that as long as you have the proper oils and good batteries. At work temps get down to -40 deg f on average but we do have plug ins available for this and they start every time.
Unless of course some one leave the damn interior light on.:mad:
Also I always let my glow plugs go through the full cycle even when in the garage. Just my little way of giving me time to check things before I start it up.

went snowmobiling in janurary and went out and started the truck at -5 and it started right up.

My 03 starts every day, summer and winter. Last year it was outside all winter and didn't get plugged in. When below 0F, I cycle the key 2x to run the glow plugs twice. Be sure to use the grill cover and the bumper "bra", that lets it warm up quicker and you get good heat.

Eau Claire, WI

I have started at down to -10 after sitting outside at work all day. DMax complains a little, but starts right up. Don't expect any cabin heat for 10+ minutes, though.

Run the winterfront below 35-40 degrees, use a fuel additive and synthetic oil, and make sure your batteries are good and you'll do fine.

I DO "plug in" once my garage gets to below freezing but this is mainly convenience, not needed but truck starts great and I have heat much sooner. I have an extension cord on a timer, run the heater for about an hour before starting in the morning.

Is there anyhting that needs to be done with the fuel cooler located in front of the tank in the winter. And would it hurt to plug the block heater in and leave it plugged in overnight. Thanks

maxedout22:
no.
no, except your wallet for the electric bill.

Everybody that plugs their truck in at night soon figures out to put the block heater on a timer. It's about a 850 to 1100 watt heater.

Just go to you local home improvement store of choice and get a timer. A heavy duty one if you desire. I set mine to come on about 2 hours before I would go to work.

Don't worry about the fuel cooler, it's not that efficient.

I've started my truck cold down to about 7° F and it runs a little rough for about 5 seconds then smooth right out. That was on Delvac 15W-40. I expect better performance this year since I switched to Delvac 1.

What Dave said...

i leave my old 6.5 plugged in 24/7
if i have to leave it out side
never noticed a jump in the bill just from it