losing coolant

Sounds like a head gasket.

 

Yeah sorry but that what it sounds like. That's quite a bit of coolant loss given that there's no visible signs of leaking. If it is, it's probably going out through the exhaust and you'd never see it. What about oil? Have levels changed or have you done a sample at all?

 

There's other possibilities but if it's blowing smoke coolant is getting in the cylinder. It's either a head gasket or EGR cooler.

No heat? Can be due to low coolant. If it's 2-3 gallons low it can't circulate properly and pump through your heater core. See if it blows hot after you top it off. If you have carpet in the truck see if the passenger floorboard is wet. That would be a leaky heater core.

 

Good thought, I would think if it's leaked that much into carpet I'd be pukin' at that point.

 

you can pull oil/pan then pressure the rad, look for drops running down inside of liners, might have to turn eng. 1/2 turn to open up pin holes in liners. small line of holes at 1.2 mil. made my 3406/E heater stop.