How to maintain your car's cooling system

[Hagerty]

Overheating is of the most familiar problems with owning an older car-and one that has provided plenty of fodder for black-and-white comedy films in days of yore. In reality, though, standing by the open hood of your beloved automobile, ducking plumes of steam spurting from the radiator cap, is no fun.
https://www.hagerty.com/media/maintenance-and-tech/how-to-maintain-your-cars-cooling-system/

[robert369]

thanks for sharing

[audiobycarmine]

What a fantastic article!

While many of us already knew most of these things, this is one of the best-written and informative pieces on the site. You've educated a good many, sir.

Bookmark it, Folks!

[DUB6]

Hey, @Sajeev, maybe you should have read this before answering the PistonSlap question about the overheating Corvair! 🤪

[Eric]

Funny you should say that --- we got a hold of this story after Piston Slap posted, and I thought they dovetailed nicely between air and water cooling!

[Sajeev]

No way @DUB6 ! There's no use of ALL CAPS to blurt out half-baked advice...how could I let something so well-written influence with my fantastically brilliant and stunningly insightful work?  🤣 

[noah300g]

"it’s an easy task to perform while the car’s off the road over winter."
It was 3 degrees F at my house this morning. Nothing is an 'easy task' while the car's off the road over winter north of Boston. 😉

[JGeske]

3 degrees! A heat wave! I am moving to Boston! It was -11 F with a 20 degree windchill in Northern Wisconsin yesterday. Better today with a 20 degree temp before windchill.

[DUB6]

Where is @Capitollobbyist in all of this discussion?  Maybe he can tell us how cold it was at the beach in Orlando this morning!  😋

[DaveA]

You live there......willingly? 😂

[PRScott]

Boston! You southerners crack me up.

[dbier]

But also a good time to double check the freeze protection of your cooling system. My car was shipped up from AZ to WI 2 weeks ago and just before sub-zero weather arrived I decided to double check the freeze protection and was surprised to learn it was just protected to about 30 degrees. Turns out the guy in AZ had drained the radiator to replace the temp gauge sensor and just filled back with water - not thinking about the cold the car would soon experience in my unheated garage. I dodged a bullet by checking and addressing the coolant mix!

[Gary_Bechtold]

Good article!

[Ken68]

Thanks for discussing this long overlooked facet of automobile maintenance. I had hoped that the author of this article would have touched base on cooling system product alternatives. I've often stewed over this particular aspect of preserving the integrity of my big block Chevrolet engine so I decided to follow Jay Leno's lead by using Evans Waterless Coolant (after performing a thorough rebuild on my 396 cubic inch 350 h.p numbers matching engine). I replaced the radiator and heater core during the Chevelle's rotisserie restoration so it made sense to switch over from the conventional water / glycol coolant. I replaced the thermostat with a lower than standard setting (170) and to a lower rated rad cap (7p.s.i). I'm now able to check the radiator level even when the engine is up to normal operating temperature without fear of a thermal geyser as would be the case using the typical water based fluid. After 6 years I can report no operating deviations or visual appearance changes. When you take away water and oxygen in a fluid that's in contact with iron (as in my case), corrosion isn't going to be an issue. The only issue I've heard about regarding this product is with immersion style block heaters. Off hand I can't remember if it had something to do with metallurgy. I think its worthwhile using, one less ongoing messy procedure every 4 - 5 years depending on mileage driven of course.

[Mogowner]

Hullo Mr Ken68, I agree with you in regard to your choice of coolant. I have Evans Waterless Coolant in all of my LBCs' and find that is extremely satisfactory, and resulted in a noticeable reduction in running temperature in a couple of them. Although not cheap, as far as I am concerned, it was money well spent.

[Inline8OD]

 Jesse gives good info above, inc. your heater serving as a small auxiliary radiator if needed.

 Avoid antifreeze like the plague lest your car exposed to two consecutive nights of a hard freeze--30 or below--- or has air conditioning, in which case you need 15% antifreeze to prevent the heater core from freezing even in Phoenix or LA in August.

Otherwise, all you need is reverse osmosis water and a good rust/corrosion preventive like No-Rosion.com -- and make sure to read their tech info link-- or Red Line "Water Wetter." Nothing else.

  Cars run cooler with straight water if you don't need antifreeze.  This allows you to advance your timing a little for better performance and fuel economy.

Soluble oil is a dated practice. Like antifreeze, it leaves a heat transfer inhibiting film on coolant passages. You do  n o t  need a water pump lubricant.

Never use distilled water, which is ion hungry and leaches minerals---like lead, tin, solder -- from your radiator and cooling system.

[72stang]

I am not sure where you got your information concerning distilled water and leaching minerals. As an engineer who worked at nuclear power plants for 35 years, I can assure you that water purity is key to the reduction of corrosion products. The water quality found in most municipal water systems significantly accelerates the corrosion process. You should always use a mixture of distilled water and anti-freeze in the coolant system.

[Dond]

Yes engines run cooler with straight water, but what about water pump lubrication? Maybe add a little water wetter or similar product.

[Mogowner]

Interesting to see an Austin Seven depicted--a vehicle manufactured which did not include a water pump, and relied solely on the thermal siphon principle. I understand that some folk have installed an electric pump as an additional means of getting the temperature down when unusually warm days occur.

[Joee383]

When you drain your coolant about half of it comes out. I usually measure what comes out to get a better idea.
I don't like using anything but distilled water so hose flushing is out. It's better to refill run and drain the system a couple times leaving it half full of mostly distilled water. Add straight antifreeze to get a 50/50 mixture.

[Inline8OD]

 I expected responses like those from "72stang" and dond who reply before reading the No-Rosion tech link cited. No-Rosion was originally formulated to protect the dissimilar metals in monstrously expensive industrial cooling towers:

https://www.no-rosion.com/tech_coolant.htm

 Re: Red Line Water Wetter, Roy Howell, their chemist, is a Cornell grad and member of the SAE, with CEO Tim Kerrigan since Red Line's 1979 founding. Like SAE member Jay Ross's No-Rosion, Roy & Company also caution against distilled water.

Dond, no, you do not need "water pump lubricant." A late Phi Beta Kappa industrial chemist friend, a lifelong gear head extraordinaire, holding two patents reminded us that water itself is a good lubricant for the carbon seals of most water pumps of older cars.

 If you're saddled with a 1936-48 Cadillac or LaSalle V-8, which Generous Motors being Generous Motors -- as a lifelong Packard, Mopar, FoMoCo, Stude, Pierce-Arrow  fan and national parts purveyor who'd early on been service mgr. at a Cadillac dealership dismissively termed GM --  you have a water pump straight out of 1930, which has a packing gland requiring periodic attention, such vintage-- even Edwardian-- constructs another matter.    But we note that's likely off subject as most here gathered have little interest or curiosity in the 120 years of automobilia,  only mid-sized egregious '60s Motown tin stuffed with station wagon engines,  stumpy rear axles, racing stripes and silly decals,  or regurgitated press releases of the latest must-have super car du jour for the arbitraging, mall developing, silver spoon .001 %.

   You might hold Hagerty's feet to the fire to provide more than Walter Mitty PR fluff and paeans to things barely out of Kelley Blue Book.

  A Chrysler engineer member of the Auburn-Cord-Duesenberg Club years ago described the drawbacks of soluble oil, or the need for any "water pump lubricant." 

 As  Kendall Oil/ Conoco Phillips petro-chemists,  themselves owning a range from prewar Packard to well-tweaked Camaro pointed out during another "must-have" round, this time a certain motor oil additive:  "If you want to stay in business, you give the public what they want,  or  t h i n k   they need."

Let's not reinvent the wheel nor pick and choose the precepts of chemistry and engineering to play online gotcha.

[dbier]

With winter here for many of us - don't forget to double check the freeze protection of your cooling system. My 68 Chevelle was shipped up from AZ to WI 2 weeks ago and just before sub-zero weather arrived I decided to double check the freeze protection and was surprised to learn it was just protected to about 30 degrees. Turns out the guy in AZ had drained the radiator to replace the temp gauge sensor and just filled back with water - not thinking about the cold the car would soon experience in my unheated garage. I dodged a bullet by checking and addressing the coolant mix!

[hirvine]

Thanks for the article. A couple of additional items should be added (unless I missed them, my eyesight is awful).

Timing and Air/Fuel mixture - especially on old cars. I chased an "overheating at idle" issue for a year on my 1960 Cad convertible. Mechanics all said that it had to be either the water pump or fan clutch. Then I found a post on the Cad/LaSalle club forum that said that it could be ignition timing. Sure enough, somebody has disconnected the vacuum advance, and at idle, the timing was retarded enough to allow flame to leave the exhaust valve, which the cooling system could not overcome. I retimed the car and problem solved. I know less about running too lean, but this is another source of overheating on old cars.

[Oldsman]

While the "conventional" cooling system was explained, I was disappointed there was not a reference to the revamped cooling system designed for the Chevy 5.7L LT1 V8 (that debuted in 1992?). Much was made of the "gear-driven" water pump used on the LT1 at the time, whose purpose was to eliminate the constant uneven belt tension on water pumps, which caused water pump seals to fail. (And it apparently worked, because those water pump seal failures caused me more cooling system failures than all other causes combined, in the 1970's and 1980's GM cars I had. Starting with my first LT1, and continuing into LS1 and LS2 engines, no more water pump failures!) Also, the LT1 "reversed" the coolant flow through the system, claiming better efficiency.
I guess I'm just surprised that those advances didn't warrant so much as a footnote, as they may have been as effective at strengthening cooling systems as the addition of coolant overflow reservoirs, which became standard in 1974 GM cars (and which may have saved many 1971-73 Chevy Vega aluminum engines from warping, had they debuted in 1971!).