Flushing cooling system

I have a 1996 Taurus with a 3.0 vulcan motor, automatic with 145,000+/- miles. I’ve had it since it had 75K.

Long story short, I had a Jeep before that required checking fluids once or twice a week. I bought my wife a new vehicle and took her Taurus. I continued my religious fluid checking and slowly stopped checking it because it was fine everytime for the first year. I drive 70 miles round trip to work. One day I got 3 miles outside of my town and my temp. guage shot up. I quickly pulled a u-turn and got home before the red. She was way up there but not in the red. I immediately thought bad thermostat and started to replace it. When I pulled the housing I expected substantial amount of fliud. NONE came out. I looked at my wife shaking my head and sure enough, I open the expansion resevoir and it was empty. I felt so stupid. Now I watch it like a hawk.

Here’s what it’s doing. About every 2 or 3 months I will need to add more coolant. Where is this coolant going? We’ve had this car a while and never flushed coolant. I found the drain plug on bottom. It is plastic. Do I need to use care, obviously, because it’s plastic? Are they notorious for being seized up? When I do flush it, can I use an additive when I put fresh back in.

I am ashamed to say that with all my automotive background, I’ve never flushed a radiator. Can I drain radiator run at water and motor at same time? Is this flushing? Do I need to prevent “air bubbles” from entering system? How so? Is there a chemical you can flush with like I use for my motor oil for every change?

Can anyone give me some tips? Can I use additives or something like “Mendtite” or “Bars” or can someone recommend something higher in quality? I’m keeping this car until the wheels fall off, so I want good stuff. It’s been a solid reliable car and I want to keep it that way.



By the way, I was also wondering if I did any damage to motor or components. This “overheating” incident happened about a year and a half ago. I’ve noticed every now and then, she’ll get a little warm. She got a little warm about 2 days ago and then I checked it tonight at work and level was low. I know where the needle sits under normal conditions so I’ll notice if she’s a little warm. I’m not running A/C when this happens. Once again, is there anything good I can put in with fresh coolant? Is there anything I should replace just as preventive maintenace? (Please don’t say “headgasket”!:slight_smile: )

Thanks again.

Unless there has been a contamination of the coolant, like an oil leak or wrong fluid poured in, a fresh water flush is all you need. Drain the fluid from the radiator, and replace with fresh water. Run the engine until 5 minutes past it getting fully warmed up. Drain and repeat until the last of the water being drained is totally clear. If this takes a few cycles, then the engine block really holds back on some water. You need to take this in consideration when adding coolant.

I like to run a 60/40 mix, so I will mix one gallon of coolant to that ratio with distilled water. The other unmixed coolant goes into the radiator to mix with the remaining clear water in the engine block. I’ll top off with the mix.

Don’t forget to replace the radiator cap and the thermostat when you do this. You may be losing coolant through an old cap that cannot maintain the proper system pressure. And, considering the age, you may want to replace the hoses as well, radiator and heater. They become suspect after 4 years of use. They tend to weaken from the inside, so replacing them is always a safe bet. Try that first. If you still lose coolant after that, then we need to investigate further. At the rate of loss, this is easily maintainable until the leak is found, or becomes more apparent.

I don’t like adding anything to the coolant, except distilled water. Tap water has harsh chemicals that may interact badly with chemicals in the coolant, and may leave hard water deposits in the engine. Distilled water has none of that.

Thanks for your response “BustedKnuckles”.

I’m glad you told me about distilled water. I’ve used tap water to top off the expansion tank. Would that introduce contaminates? Should I then flush with something?

Sorry if I seem ignorant, but I cannot find an actual radiator cap, just the cap to the expansion tank that I feel is pressurized when trying to open after operating temperatures are reached. It took me a while but I finally found the drain plug, but it’s plastic. My main concern is the brittleness of it. I can be gentle but I want to know if a)can I get another plug at a auto parts store b)are they prone to breaking?

Talking about a slow loss of coolant, is there anyway that the engine is “cooking” it and sending it out the pipes “undetected”? The car does not smoke or use oil. In fact when I got it It said “Motorcraft” on everything. I recently changed all plugs and wires. Unfourtunately I’ve had to put in a new tranny. Other than that, the car runs like a top.

All my hoses look okay, in fact they still say “Motorcraft” on it. Is that even more of a reason to change everything. I’m not supersticious, but I’ve heard that when you replace a couple of parts, the other parts get envious then it becomes a snowball of replacing parts. Am I crazy for thinking that way? If it ain’t broke don’t fix it? I do like the idea of preventive maintenance.

By the way, what’s a good brand of coolant to get? How does “Prestone”, “Peak”, and “Purple Power” (they make coolant, right?) all compare. Is there something else I’ve never heard of? Is buying pre-diluted coolant okay-not-okay? Besides the fact that you’re paying more for less fluid than buying undiluted and diluting it yourself and getting more for $$$$.

Off the top of your head, do you know the capacity of this Taurus’ cooling system? I don’t know if it’s in my owners manual, I will look it up as well.

I don’t know if this is relevant, but after my 35+ mile trip to work, the car smells hot, but it’s not overheated. What am I smelling? I don’t like it, it worries me. It ALMOST smells like hot electrical but I think that I might be imagining this. I’m just trying to figure out my fluid loss. My work vehicle is a 1997 E-350 Ford van. I’ve driven this van day-in and day-out and never has it even dropped on fluid. My wife’s '99 Expedition is the same way. I’m just wanting my Taurus to be the same way. I drive like an old man, I’m 27 going on 57 or at least I feel that way.

Thanks again, BustedKnuckles and to anyone else who can give their imput.
Until later my friends.

HI JP. I just went through this on a 2001 Taurus.

The expansion tank “aka” coolant reservoir does pressurize to about 16psi. It’s think plastic but you may have developed a hairline crack from constant expansion and contract. Mine was cracked on the bottom of the reservoir against the fender so it was hard to find. You might pull that and have a look. Since I had to disconnect hoses to get the coolant tank out, I replaced the hose clamps just to be sure. It’s cheap insurance. The tank was about $60 or so from a parts store.

You said you can smell the car when it runs hot. The coolant reservoir is close to the AC/heater inlet to the mail cabin, so this might support the cracked reservoir theory.

After getting the car hot, you might try parking it on some cardboard, It might help locate the leak.

Before you go flushing, the first thing you need to do is top off the system with water, connect a cooling system pressure tester, pump it up and find that leak. You might be surprised. It could be something as simple as a loose hose clamp or a leaking hose or a cap not holding pressure. Fix the leak then flush the system. If you flush it now then fill the system and discover you have a bad water pump, heater core, or even a bad head gasket, you just wasted your time and money flushing. Stop leak formulas are quick, get myself off the side of the road band aids. You’re not on the side of the road so fix it right.