2020 3.0 Duramax Winterizing Questions

TheRealZatarra · July 25, 2020

Firstly, my truck is the 2020 Silverado RST 3.0 Duramax. I live in remote interior Alaska and we need to do a bit more Winterization here than just a block-heater. Last year we had a couple separate weeks of -50 to -64! degrees here. Typically we do an oil pan, block heater, transmission, battery heater pad (or trickle charger) and use an electrical outlet splitter to connect all of those back to the plug which hangs off the front. Now, I have searched far and wide for some engine diagram to show me where the block heater is on the LM2 3.0 Duramax but I cannot find it anywhere. Man I miss having Chiltons/Haynes manuals available but I guess those are becoming things of the past. I have climbed under it and started following the wire bundle from the from bumper backwards, but lost it in those tight spaces on the drivers side. I'm guessing the block heater is on the driver side but I cannot find it. I'd like to combine the power plugs somewhere back near the block heater so that I do not have to run heater pad cables so far back and under to the transmission, oil, etc.

I'm also half tempted to bypass the GM power cord, which apparently won't conduct until -18 degrees because "you don't need it". Well, that doesn't make good sense. #1 that thermistor which blocks current is very likely to fail at some point, cutting off ALL of my engine,trans,oil pan and battery heat which would be QUITE inconvenient. Secondly, error codes or no, I disagree with the idea that you don't need to plug it in at -15 degrees. If you run your engine, get it hot and then park it and let it go back to -15 and then run it hot again (repeat,repeat) you will build condensation in all those parts... which is another reason to plug these things in during continuous cold weather. I could run a completely separate electrical splitter and have *another* cord hanging out the front, but sigh, this is a NEW truck and I'd kinda like to avoid that.

I've also been looking for a front end bra of some type, to help block some of that -50 degree air from cooling down my engine compartment (up here that really does help) but I'll be damned if I can find one anywhere for the 2020 Silverado RST. If you know of one please help me with a link?

Lastly I've had a funny quirk happen to me twice on this truck. I go to start it, press the ignition button and rat-tat-tat-tat-tat-tat-tat-tat is unstoppable for about 45-secs to 1 min. It's weird, but then it stops, I hold my breath, press ignition again and it has always started up without a problem but that's weird. Anyone else had this happen?

Thanks in advance for any helpful advice.

BurnsMax · July 25, 2020

I'll see if I can find a diagram. The heater works when plugged in, but it isn't recommended until below 0F cause it can cause issues where it turns on the fans full speed all the time(I believe there is a tsb fix for this). You don't need a bra because your shutters will stay closed to keep the engine hot. They will open and close to keep your engine at optimal operating temperature. When does your truck act like that when start? Cold or warm temps. May want to drain the water out of the fuel filter

TheRealZatarra · July 25, 2020

Thanks for feedback.

My engine has never done the stuttering start thing in cold weather, only warm weather. I'm certain there is no water in the fuel. I even drained it. I'm willing to bet it's a software bug, because after the 45 secs of attempting to start, it starts no problem next attempt without exception.

BurnsMax · July 25, 2020

You're welcome. Try the other FOB and make sure there isn't an issue with that one. Mine starts instantly. May need to bring it in to see what is going on

TheRealZatarra · July 26, 2020

22 hours ago, BurnsMax said:

You don't need a bra because your shutters will stay closed to keep the engine hot. They will open and close to keep your engine at optimal operating temperature.

I don't know what you mean by shutters. Looking right through my front grille I can directly see the radiator with no visible vents or flaps. What closes? See attached picture o took looking straight back to the radiator.