Cooling System Update

The specifications for the 1800E states that the cooling system has a capacity of about 2.2 gallons. My car took about 1.5 gallons of coolant after the heater and radiator install, which can only mean there's still some air in the system that needs to be expelled. My car's manual did mention that it may take a long while of normal driving to completely bleed the system. I took the car out for a spin around the neighborhood this evening to get coolant circulating and to test the heater. Idle is still rough and erratic, presumably from condensation in the fuel system - so I dumped a bottle of iso-HEET water remover into the fuel tank, and hopefully that problem will go away after awhile. Oh, and I also bought a bottle of Chevron Techron to clean the fuel system and fuel injectors. The boys on the 1800List forum seem to go ape-shit on the stuff, so I thought "what the heck" - can't hurt right?

The good news is the heater works great, the blower is strong, and it's now pleasant to drive in the winter. The bad news - I discovered that once the engine reaches normal operating temperatures, it'll stall once my foot is off the gas pedal! Everything is fine when I'm driving except for when I take my foot of the gas pedal to slow down or stop at an intersection, the engine idles low and eventually stalls. This happened twice when I was driving around this evening. On the second time, the engine refused to start. Luckily, I was only 50 yards away from my driveway, so I pushed it the rest of the way home.

About a couple of hours later, the car started again on the first try. I suspect a bad thermostat - the one thing I didn't change when I overhauled the entire cooling system. The engine however, didn't show any signs of overheating - temmperature gauge normal, oil pressure normal, no steam or smoke from the engine. Who knows? I'll try replicating the problem another day.

Heater Reinstalled

It's ALIVE!!! The rebuilt heater is back in the Volvo. I filled the cooling system with the first gallon of antifreeze and water, fired the engine up, and everything worked! The heater blower works ... on both speeds, high and low. The little green light in the heater control housing works! The car started up - which I'm extremely happy about ... although it's been idling rough. I might have let the fuel sit for a little too long without any fuel preservatives. It's either that or perhaps its idling rough because of a partially filled cooling system? I'm not sure if there is a "correct" method of replenishing coolant - I did what seemed logical to me. First, I set the heater temperature control to high (lever all the way down) to ensure that coolant gets into the heater core. Next, the initial fill was done via the radiator. Once the radiator was full, I then filled the coolant overflow bottle to the "Max" line, removed it from the mount and held it above the radiator to fill the hose connecting it to the radiator with coolant. The coolant overflow bottle was then reattached to its mount and recapped along with the radiator. Finally, the engine was started and the water pump did the rest. As the engine takes up coolant from the radiator, by some miracle of fluid dynamics and pressure, the radiator just sucks what it needs from the coolant overflow bottle. Subsequent refills are then done via the coolant overflow bottle as the the entire system gradually fills up on coolant.

Before:

After:

So far, I've completed 2 rounds of filling coolant, setting the heater temperature to high, and running the engine to normal operating temperature to flood the cooling system (radiator, engine, heater core) with coolant. By days end, I've used up 1.5 gallons of premixed antifreeze and water, but I'll give it another go tomorrow to see if it'll take more. The following are some before-and-after photos of the bottom half of the heater box from the interior of the car:

Before:	After:
Before:	After:

Here's a photo of the heater controls with the lights on. This light comes on when the parking or headlamps are on. They were not working before - in fact I didn't even know they existed! All I did was clean up the bulb housing and ensured that it was properly grounded. This bulb does not have a separate "ground wire". It only has a single "hot" lead. Grounding is done by ensuring proper contact with the heater control housing. From the research I've done, this green light only existed in the 1972 onwards ES models, which leads me to believe that some previous owner must have swapped out the heater control housing - bonus for me!

Heater Controls With Light:

All Pieces Back In Order: