Heater heat

Sometimes, the heater hose nipples on the water pump, head, intake or wherever, will accumulate some corrosion on the inside, slowing down the coolant flow. You can change 'em out or get a rat-tail file in there and clean 'em out.

Same goes for the heater core. On one of my other cars, my heater wasn't blowing hot at all. After some checking, I found out that the core was completely plugged up solid with....what looked like.....calcium deposits.