Hi I have A 2001 SS 3.8 I run Mobil synthetic oil it is 10W30 it has A coolant heater I also live in Massachusetts and we have cold spell . I am wondering how long can it be plugged in for and at what outside temp is to hot to plug it in and I know not to plug it in in the summer what I mean what winter temp is to hot . I mainly want a idea if it is going to be below 20 degrees out could it be plugged in all night does anybody know about these heaters have called a couple of dealers they seem to have no clue

Thanks

 

20 degrees or -20? If its only 20 above zero I wouldn't bother with the heater at all. Its been below zero [daytime high temp] where I live all last week and my monte starts just fine. If it is standard block heater leaving it plugged in overnight is just fine. So I would assume a coolant heater would be safe aswell. Antifreeze/coolant freezes at -35 to -37 degrees f so I think you are fine either way.

 

thxs that was A big help Have A good one

 

The cold is bumming everyone out. Couple more months man.