Posted by Alan Bowes on September 05, 1998 at 13:19:15:
In Reply to: m-37 heaters posted by scott walen on August 31, 1998 at 18:32:49:
If the heater core is clean (inside AND out), the ducts are tight, and the engine has a proper thermostat, the fender-mounted heater should work just fine. If you need to coax a little more heat out of it, you could put an "arctic front" insulating cover over the front grill. The extra heat inside the engine compartment helps keep the whole firewall area a little warmer. Also, in extremely cold environments, the heat loss through the engine surfaces and the heater is sometimes sufficient to cool the engine below thermostat-opening temperature, and the arctic front reduces this phenomenon, which tends to happen when you are not working the engine very hard and the outside air temperature is colder than 20 below zero F.
I've lived in Alaska and northern Minnesota and I've had this happen with two or three different vehicles, especially when just putting along at low speeds where the engine isn't doing much work. In all cases, a cover in front of the radiator cleared up the problem.
Another suggestion is to make sure that all of the door, window, top, and shift/transfer/pedal boots are in good shape and fit properly. This will reduce cold air drafts.
Have fun,
Alan