It used to be so simple. Get out the antifreeze tester and sample the radiator water. We added antifreeze at the beginning of winter.
Water from the hose kept the Rad full for the rest of the year.
Today the various types of Coolant makes my head spin. You have to check the car manual. Popular Mechanics tries to explain the types of coolant.
Link Car Coolant — How To Choose the Right Car Coolant
What about routine Top Offs for the Rad? Can I add water at a service station?
You don’t have routine top offs any more, because you use stuff that doesn’t boil away.
Where do you live?
Here in FL we don’ friggin’ care about no steenkin’ freezin’. There are plenty of anti-corrosives even in heavily diluted antifreeze. Just add water for years.
It being Nov, if you’re in a place that snows, and especially one that stays below 32F more than overnight, then maintaining a proper mixture matters more. Lots more.
My habit in freezing country was always to buy full strength, mix it per the instructions (typically 50/50 w water) and refill only with that. Never from a hose. Anything else risks having an unknowable concentration with unknowable freezing resistance. Given the cost of a new engine in a modern car, keeping the coolant / antifreeze at the proper mixture to prevent a catastrophic block split seems like very cheap insurance.
I use a Preston antifeeze tester. It indicates the freeze and boil points in the sample.
I’m in Arkansas. We rarely go below 20 degrees F. But reach 100F in the summer.
I’ve only had temp issues driving to Dallas in my old 2000 Ford van. It gets hot in Texas. Didn’t boil over because I shut off the AC for awhile and opened windows.
Antifreeze at 50/50 doesn’t raise the boiling point by more than about 10F. And reduces the heat transfer capacity of the entire system by more than that percentage.
If engine cooling is marginal in hot weather, the issue is not your coolant mixture, it’s the overall functional condition of the water pump, radiator, thermostat, and radiator cap(s). If that’s not up to snuff, turning off the A/C as you did is helpful, but turning on the cabin heater is even more helpful. Albeit miserable for the people in the vehicle.
The last time I checked my radiator fluid in my car was around 1998. Haven’t needed to.
Yeah, unless there’s steam coming out of the car (like my 1981 Accord used to do), I never really check the fluid levels. I guess the mechanic does that when he changes the oil?
Anyway, I’m pretty sure it’s all just 100% antifreeze in there.
same.
Keep the reserve tank topped with premix and never think of it again.
Do modern cooling systems even need routine flush-and-fill any more?
Should never be 100% antifreeze. Not from the factory, and not after a coolant change. The stuff is meant to be diluted at 50/50 unless you’re in the Arctic then more like 70/30.
OTOH, starting a few years ago the antifreeze manufacturers started selling “pre-diluted” antifreeze to be used right out of the bottle as-is. For your “convenience”. Of course it contains 1/2 as much of the expensive chemicals since 1/2 of it is now very cheap water. Of course the price is as high or higher than the full strength stuff. For their convenience (read “profitability”).
If someone has always bought pre-diluted they might well believe their cooling system is charged with 100% antifreeze.
Aside: Cars from the 1960s to the (WAG) late 2000s seemed to consume a lot of coolant over their life whether the car was new or old at the time. Cars since ~2010 consume hardly any coolant whether new or old at the time. Hmmm.
Routine top-offs haven’t been a thing in decades. I have a couple of antique cars that need routine top-offs. Any car I’m familiar with since the 1970s has had an overflow reservoir. When the car starts, as long as the radiator cap is working properly, if the coolant level is low the car will draw coolant from the reservoir. Just follow the little hose from near the radiator cap and you should be able to easily locate your reservoir. It’s a little plastic container that should have a fill line on it somewhere. If the coolant level drops below that fill line, then add coolant.
Maybe if you live in someplace like Arizona you’ll need to top it off occasionally, I dunno. But here in Pennsylvania I don’t think I have ever had to add coolant, with one exception when the radiator in my old truck sprung a leak.
You should always add a 50/50 mix of antifreeze and water. As was already mentioned, if you top off with water, you run the risk of the coolant freezing in the winter. Water expands when it freezes, so the risk there is a cracked radiator, or worse, a cracked engine block.
Antifreeze is most commonly sold in 50/50 premixes these days anyway. You can still buy 100 percent antifreeze in most places if you really want it, but the majority of the antifreeze on the shelves will be 50/50.
They still need flushed, but usually nowhere near as often as old cars did. Some are every 3 years or 30,000 miles. Others are every 100,000 miles.
Man, you really are from PA.
I’m sure you’re right. Since I never top it off and leave the flushing to the mechanic changing the oil, etc., I don’t really know what’s in there.
The trick I learned was to buy the first jug as 50/50 then next jug is full strength, divide into the now empty jug and top off each with distilled water. The elephant in the room is: If you need three jugs of antifreeze, you have more of a money concern then paying 4X the price for the diluted stuff.
Heh. PA grammar at its finest!
I had a bad radiator cap on my old van. It took a couple weeks to figure out why I was losing coolant. I kept searching for a rad leak. I finally tried a new cap.
Last year I had to learn how to do an antifreeze flush because like an idiot I accidentally put windshield washer fluid in the coolant tank. It took me a few days to figure out why the windshield washers still weren’t working (if it just said, “Coolant” I never would have made that mistake, but that ambiguous icon…no, I’m still an idiot).