Coolant replacement time

Well, I was trying to get more leverage.

That vent plug will never ever vent. I have to accept that...

But again, with the sensor out, it shouldn't make a difference. Still doesn't explain why that other 1.5 gallons just stayed in there.

Next time, I may put the rear wheels on ramps.
 
1997ThunderbirdLXV6 said:
Well, I was trying to get more leverage.

That vent plug will never ever vent. I have to accept that...

But again, with the sensor out, it shouldn't make a difference. Still doesn't explain why that other 1.5 gallons just stayed in there.

Next time, I may put the rear wheels on ramps.
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The other 1.5 gallons is in the engine block. You aren't going to get it out easily. This is how it is with any car.
 
Take a hose off the heater core quite a bit more will drain out. Had this happen to me more than once at inconvenient times
:LOL:

But as Kevin said a partial change is just fine. As long as the coolant wasn't in bad shape
 
If the coolant is questionable (color, texture, smell), you could also do a radiator flush, empty the radiator and then fill. You can either use a garden hose fitting on one end of the heater hose, a garden hose on the engine fitting, turn on the water, turn on the engine, turn on the heater, wait till the fluid is clear, put it all back together, drain the radiator and fill with the proper fluids. Don't forget to burp the system.

(I know, nobody asked)
 
Here's a question:

Does coolant always get pumped through the heater core, regardless of climate settings? Or does the coolant somehow bypass the heater core when heating isn't selected?

My assumption was always that coolant went through the heater core regardless of climate settings. The climate settings just regulate whether or not air gets blown past the heater core via the blend door.

But...in lots of instructions for changing the coolant, during the initial engine start and burping process, I read the instruction to turn heater on high. Why? What difference does it make?
 
Our cars constantly circulate coolant through the heater core, some older cars used a heat valve that blocked it off when not in use.
 
XR7-4.6 said:
Our cars constantly circulate coolant through the heater core, some older cars used a heat valve that blocked it off when not in use.
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...which caused stagnate water, which caused corrosion which caused leakage which caused replacing the heater core...
 
White Lincoln said:
...which caused stagnate water, which caused corrosion which caused leakage which caused replacing the heater core...
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Coolant gets acidic over time whether it’s circulating or stagnant, it’s good practice to change it every few years to prevent it no matter the system.
 
XR7-4.6 said:
Coolant gets acidic over time whether it’s circulating or stagnant, it’s good practice to change it every few years to prevent it no matter the system.
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Check mark that.... 2-5 years as I remember reading (or was it 5-8?). Worse (shorter end of cycle) in humid climates I think I read too.

I think I am due on the Town Car.
 
White Lincoln said:
Check mark that.... 2-5 years as I remember reading (or was it 5-8?). Worse (shorter end of cycle) in humid climates I think I read too.

I think I am due on the Town Car.
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I’m a 2-5 follower myself(I’m actually a little overdue). The rule of thumb is interesting, electrolysis occurs because of the coolant being in contact with dissimilar metals(eg iron and aluminum) so I always wondered if there’s a different rate of it occurring when the heads/block/radiator/heater core are all all aluminum vs. an iron/aluminum combo. I guess I could check with my multimeter but I don’t really want to know right now lol
 
The liners are iron, so it's not all aluminum. The only thing keeping them from rusting out of the block is the intimate contact.
 
That is the biggest part at killing galvanic corrosion; bonding them together. That can be a wire, or swaging together with a press.
 
KevinVarnes said:
It is difficult to completely drain the entire engine. I'm sure the block has plugs on it somewhere, but I'm also sure they aren't easily accessible. I'd say you are doing alright getting 1.5 gallons out. When I do coolant drain and refills I just drain the rad and maybe pull a rad hose, but you'll never get everything out. You can also treat it like a partial trans drain and refill and repeat the same procedure in a week or two.

I've been getting my traditional green coolant at NAPA. Seems to be in stock there. All of my rigs run green so I stay stocked up.
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You can always do a old school cooling system flush with the garden hose. Flush it till it comes out clear, then close everything up and refill with antifreeze. Be sure to turn on the hearer so you flush the core as well. Done it for years on all my old cars. You'd be amazed how nasty stuff comes out sometimes.... especially in the block.
 
Turning the heat on in these doesn't help; we don't have a valve. Blend door does hot/cold.
When I change mine, I pull the lower hose from the rad into a 5g bucket. Pull the drain on the block after the rest drains.
I put a water hose in the overflow, and let it run for a bit. This gets all the sediment out.
Put the plug in the block with teflon, and reconnect the lower hose, add a full jug of prestone,then fill the rest of the way with distilled water.
I take it for a drive, to burp out the air bubble in the coolant crossover, when you get back, the reservoir will need refilling, IF you got the bubble out. Keep the rest of the water for adding.
You will use one jug of AF, and 3 of water. (you end up with a ratio of 2 of af to 2.5 is gallons of water.)
Do Not use tapwater except to flush, and drain it all before refilling.
If you see white sediment coming out when you flush it, somebody used tapwater before.
 
Yes, on a 4.6 anyway. :) It's like the oil alley plugs, only in the water jacket. both sides, toward the back ,~2" above the oil pan.
 
I was pretty busy these last few days, but I still wanted to bring this thread to a proper close.

The morning after my coolant drain/fill, engine cooled overnight, the coolant was in the overflow bottle halfway between hot full and cold full. That checked out because that's the normal drop from a bottle that was at hot full when the engine was hot.

I started driving and pulled over once the engine was at operating temperature. The coolant should now have been at hot full. It was not; it was still halfway between the markings. Air must have been burping out gradually.

I filled the bottle to the hot full mark and continued driving.

I pulled over again a while later, and again the coolant was halfway between the markings.

Again, I filled the bottle to the hot full mark and continued driving.

I pulled over again a while later, and...coolant was still at hot full.

Apparently getting all the air out is a very gradual, somewhat time consuming process. I monitored engine temperature during all of these drives, and it was always in the normal range.


What I learned from my first ever coolant drain/fill is A. that I only get out a portion of the coolant (so I'll probably do this again fairly soon), and B. that it can be done without using the vent plug (by using the sensor to vent instead).


Thanks to all for your help as always!
 
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