[t vago]

In other words, a coolant-based hot air intake.

I have removed the cold-air intake tube from my truck, and have re-installed the stock induction setup. I purchased the smallest transmission oil cooler I could find, and have mounted it to the filter box, after the filter element. This will be the intake heater. I decided against placing the intake heater before the filter element, as I do not think that the intake heater should serve as a pre-filter, nor do I think that the intake element would like being heated up to well above ambient.

The coolant lines have been routed out of the intake box, but they have not yet been connected to the coolant system. I plan to use a 4-way heater valve to connect the intake heater to the supply heater hose. When disengaged, the heater supply will go directly to the heater core as normal. When engaged, the heater supply will be re-routed to go through the intake heater first, then go to the heater core as before. The heater valve is controlled by engine vacuum - I will use a vacuum solenoid, controlled from the cabin, to switch the intake heater on or off.

The above setup is for demonstration purposes; once I have seen a satisfactory A-B-A result set, I will probably do a Y branch instead, in order to have full heat capacity to both the heater core and the intake heater.

I plan to have the hoses and control circuit hooked up tomorrow, prior to my work commute.