Coolant Flush and Refill Quantity (Won't take 2 Gallons)

[SP3]

Just recently changed out the coolant on an R16. I drained and then did 3 intervals of filling with water and draining. By 3rd round was a little clearer but still rust colored. I then jacked up the rear of the car to try and drain any remaining in the block before refilling with new coolant.

My question is the Tech Wiki section states the cars take a 2 gallons. I was only able to get about a gallon and a quarter in before full even after burping the system and driving it for a while.

I was using Preston 50/50 pre-mixed. Any thoughts on why it is filling before 2 gallons? Stock radiator. Not sure if it has been cleaned out but no episodes of overheating.

[notoptoy]

Do you have the heater hooked up and did you flush that, and therefore refill it as well?

[Linda]

Could be rust in the block. On my engine I was amazed how much sediment can come out of there , and you have to stir it up with a coat hanger,. Can’t see how you could clean it without the engine being out. Maybe drained then a wet or dry vacuum on a smaller hose down the freeze plugs...a giant pain even if it worked
Linda

[Mackn367]

Did you measure how much coolant was drained? If so - what's the difference of that amount? Maybe it wasn't fully drained. Also +1 to what notoptoy says on the heater core. When I removed my heater (after I drained "all" of the coolant) there was still quite a bit of coolant in there.

[SP3]

Thanks for replies on this.

So I pulled out a gallon of coolant and added back in about a gallon and just shy of quarter of 2nd gallon. Does the Heater hold close to a gallon?

Apologies if this is obvious or easy answer but not with car now and never done before. How does one drain and/or flush the Heater assy/core? Do you just disconnect the hoses at the firewall in engine and can it be done separate from the radiator or does one need to drain whole system again?

[theunz]

If you really want a thorough flush you can disconnect the top radiator hose and put a garden hose in the radiator. Once the engine gets up normal operating temperature the thermostat will open and the water will start to circulate. You want to have your heater temperature control set on hot so that the water goes through the heater core. Keep the garden hose turned on just enough to keep the radiator full. Remember that as the thermostat starts to open, the radiator will empty quicker. Let the engine run long enough that you see nothing but clear clean water coming out of the top hose.
You will never get all the water out of the system, short of draining the block and blowing air through the heater core. I add a mix of 50/50 antifreeze, but sometimes add a little extra straight antifreeze to compensate for the water that didn’t drain.

[Linda]

You can run water thru the heater hoses to flush out the heater if you think there is rust in there . Low pressure on the inflow and use a bucket to catch the outflow. Just done on my other car.
Or just flush the radiator. There are those chemical flushes too FastFlush etc
Or just get the radiator cleaned out by a shop.
The aluminum radiators are nice, no more cooling issues
Linda

[Habitat.pat]

There is a drain petcock on the side of the block. You might open it up to drain the engine.

Peace,
Pat