Does anyone know for sure what the cooling system capacity is for a gen3 3.3/3.8 with the HD radiator and rear heat?
There seems to be several different numbers out there, most commonly 10.5, 13.23 and 16 quarts. I've also seen that rear heat adds 2.9 quarts, but it seems there should be at least 1 quart difference for HD/no HD since the longer lower hose and larger radiator would add at least a quart.
The last time I filled the radiator 2.5 years ago I used the 16 quart figure and added 9 quarts of coolant to aim for 55% concentration. Now I have lots of green glop (color and consistency of pea soup) in the expansion bottle. I bought a coolant tester and it shows a very rich mixture, around 70%.
I'm thinking now that the 13.23 quart number is with HD cooling and rear heat based on:
* 9/13.23 is 68%, which seems to be close to my current concentration.
* 13.23 is the only number given in my T&C Limited owner's manual and all Limiteds should have HD radiator and rear heat.
* 10.5 + 2.9 is about 13.23 so maybe the 16 quart number adds the rear heat twice.