Do you ever change your automotive anti-freeze?

[Rusty Heap]

I was thinking the other day, about when was the last time I changed out any of my cars anti-freeze?


I have a floating ball "hydrometer" and it tests fine for temperature rating of protection, but I'm wondering if anyone else ever flushes/back flushes their radiator as a common maintenance item in modern cars?


enlighten me.

[Laneco]

Believe it or not, YES, you need to flush it...

The coolant becomes acidic which (among other things) eats head gaskets and works to dissolve the metals in the engine/cooling system.

Plus, it turns into sludge. I can't picture anyone on this site letting any condition of a vehicle go so badly that this occurs, but I did have to approve a couple of REALLY expensive repairs on some of my company's vehicles due to deferring this maintenance item.

Somewhere I have a picture of the cooling system in one of our Fords that never had the coolant changed. The nice yellowish motorcraft anti-freeze had the appearance and texture of cheeze-whiz.

Seriously. Save a big buck down the road and dont' defer this item. Flush away.

angela

[GH85Carrera]

On my 911 never,

On my 1986 El Camino I change it ever other spring. When I swapped my engine after 300,000 miles I pulled the radiator out to get it out of the way. One of my buddies suggested "while I am in there" to take the radiator to a shop and have it cleaned. I handed him a flashlight and let him look inside and he saw how clean and corrosion free it was. That was after over 150,000 miles on the radiator. Antifreeze is not that expensive, and fresh clean fluid has to be better for the water pump and all the parts it is in contact with.

I know some new cars have "lifetime" transmission and antifreeze and 100,000 mile spark plugs. That is great if you plan on selling the car after a few years. I have had my El Camino for 20 years and plan on going another 20 years in it. I have not had a car payment in this millennium, and my Elky is worth more than I paid for it.

[onewhippedpuppy]

Yes. There's no such thing as any lifetime fluid. I normally try to follow the recommended factory maintenance guide, unless it just has silly intervals.

[KNS]

Every two years on my 325i.

[Head416]

I agree in theory with changing it out. In practice I do it once every 10 years or when replacing a radiator.

[vash]

honestly, it is the hoses that bother me.

i change them, and the fluid goes away at that time. i hate the project. collecting antifreeze is less than tidy.

[VincentVega]

Flush not so much, but try to drain and fill every other year or when hoses start to look questionable.

[Laneco]

Ha! Found the picture! This is one of my company's vehicles - a 2006 Ford with just about 80K on it when the picture was taken (in 2011). Coolant never changed. Vehicle was towed in for overheating...wow - ya think?

We researched through both Ford and independent contacts and all agreed - coolant will turn acidic, eat away and leave nasty deposits behind. This coolant is the yellowish stuff that Ford uses (all coolants will do this) and this one happens to turn into "cheeze whiz" like stuff. The more acidic it becomes, the more of the engine materials it eats and the more deposits left behind.

This was a $3,800 repair bill by the time we were done with it (water pump, radiator, heater core, hoses, t-stat, etc). I suspect we'll lose the head gaskets in the not too distant future, so that will be another couple of grand....

So. Spend a little now, or a lot later.

angela

[island911]

Well, unless you want a Rusty Heap . .. you should at least replace the sacrificial metals.

[recycled sixtie]

After reading Wayne's 101 book, I have the real Porsche antifreeze and am set to put it in or have it put in. Wayne's book scares me what with the electrolysis etc. 2001 Boxster with 40 k miles probably never been done for a while. Can't wait as winter and cold weather is around the corner.

[vash]

how do you bleed a heater core, if it drains completely?

[Rick Lee]

I see this job in my near future for the wife's '08 328i. It has 41k miles on it and I have to assume the radiator hasn't been touched. When should I get to it? Sooner or later?

[cashflyer]

My father just had to have his truck towed this morning.
2001 Dodge. Original antifreeze, except for any make-up added over the years.
Problem? Freeze plug rusted and blew out when the engine got good and warm.

Even if the anti freeze / anti boil properties are testing in the "good" range on the hydrometer, I'd say that the coolant needs to be changed once in a while to keep up the concentration of active rust inhibitor chemicals.

Of additional note, some engines that feature aluminum heads and blocks will have a sacrificial anode plug that should be changed out occasionally. Once the plug is dissolved, then the acids start working on the aluminum.

[Tobra]

Every other year. Drain it, fill with fresh using distilled water to dilute, drive it until the heater gets warm, park it and drain/fill again. Does not get 100% changed, but good enough. On the miata the coolant always goes through the heater core so I just do it once.

[pwd72s]

Originally Posted by vash

how do you bleed a heater core, if it drains completely?

Prestone sells (or used to?) a neat little backflush kit. You install a fitting on a heater hose that is capped. There is another fitting you can screw to that fitting that allows a garden hose to be screwed in.

Thanks for the reminder..I should do this to my old Dodge powerwagon.

(edit) Did a search...here's the link
http://www.prestone.com/products/print/461?popup=1

[onewhippedpuppy]

Originally Posted by pwd72s

Prestone sells (or used to?) a neat little backflush kit. You install a fitting on a heater hose that is capped. There is another fitting you can screw to that fitting that allows a garden hose to be screwed in.

Thanks for the reminder..I should do this to my old Dodge powerwagon.

(edit) Did a search...here's the link
Prestone® Flush N Fill Kit | Print View | Products | Prestone®

I've used that before, pretty slick device for not much money. Though on a newer car, or one that has had the coolant maintained, just a drain (radiator and block) and refill is probably sufficient.

[desertt5]

I have always drained, filled with distilled water then ran car to get to temp. Repeat till what drains looks clear. You then have close to 100% distilled water.

Drain again and add 1/2 capacity of colling sytem with preferred antifreeze. You can also remove the t-stat for faster mixing if desired. Most cars use about $12 in distilled water that I have done.

I do it about every 2 years also.

[RWebb]

no need to do this every 2 or 3 years if you use a quality coolant - I agree with 10 years, or maybe 15 and with replacing the rubber hoses, BUT you do need to get a chemical test done every year or two

modern coolants contain buffers to solve that acid problem mentioned above - the buffers will eventually be "all buffered out" which is why you need to test; oil test labs can test your coolant as can some major tire chains; they also sell test strips but I expect a lab will do a more comprehensive set of tests

also be certain to use distilled water - tap water often contains minerals which can cause damage

[fastfredracing]

Here is a pic I took of the water jackets in the head of a 4.3 I was putting intake manifold gaskets on. I had to flush the life out of the heater core, and the radiator to get it to make heat in the cabin, and to stay cool. This had about 140k, and had probably never been changed