Motor Cool Additive

[b2a1]

I have been reading where quite a few members have trouble with radiator temps running on the hot side. Has any one ever used, or heard of a product called, Interdynamics "Motor Cool" cooling system additive? Any pros or cons?

Frank

[barry22]

The type of additive you're referring to can be purchased at auto supply stores. These additives increase the ability of your coolant to conduct heat from your engine to the surrounding environment. This type of product produces only a small amount of improvement in reducing your engine temperature and more than anything gives people an added excuse to avoid tackling the real reason a car's cooling system is running too hot. My opinion is that these type of additives are a waste of money that can be better spent on finding and fixing the cause of a hot running engine.

[Reatta Man]

Agree.

If your car's temp is creeping up, or is regularly overheating, I would focus on the following:

1. Use a new thermostat in the OEM temperature range. A non-computer car can safely run a 180 or even a 160 degree thermostat. Also, use a name brand product. Avoid Robert Shaw thermostats (often sold at discount stores such as Auto Zone) as if they were radioactive. Use a Standard, AC-Delco, MOPAR or Motorcraft or similar product.

2. Get the original radiator rodded out at a professional radiator shop. Do NOT bother with the do-it-yourself radiator cleaners. The days of getting something effective, like lye in a DIY product are long gone. One easy way of checking to see if your radiator is clogged is to feel the air moving through it once the engine has warmed up IF YOU CAN DO IT SAFELY. For example, if the air is hot in most areas, but in one area, the air seems cooler than the others, that is the area that is clogged.

3. Get a new thermal fan clutch.

4. If your car doesn't have a fan shield, get one. If you are not familiar with them (many non-A/C cars came without them) the fan shield forces all air moved by the fan to be pulled through the radiator. It also provides some (not a lot) of protection from getting fingers, tools, neckties and other things caught in the fan while the engine is running.

5. Get a bigger fan (5-blade vs. 4-blade, or 7-blade vs. 5-blade). This is especially true if your car has air conditioning, or is used to tow practically anything. And, if you added air conditioning, you may need to really look at upgrading your factory cooling system. A non-A/C system will not have anywhere near the heat handling capability of a factory A/C set up.

6. If your car originally came with some sort of air deflector under the radiator and it is now missing, replace it. This deflector is little more than a plastic or metal wing looking device that forces low air up and through the radiator. It does nothing to cool your car while stopped, but forces up a LOT of air as soon as you start moving.

7. If your car originally came with a rubber deflector or gasket either on top of the radiator or radiator support bracket, but the deflector or gasket is now missing, replace it. These were designed to prevent air from going around (or over) the radiator and through the engine compartment without cooling any of the liquid.

Bottom line is this: Don't put too much faith in these miracle-in-a-can products. If they worked that well, many cars would either come with the product in the car's system from the factory, or the factory would recommend you use them in older cars.

Good luck.

Joe

[Mark Shaw]

This reminds me of the "patent medicines" sold in the old west.

In older cars with non-pressurized cooling systems, plain water is the best coolant. Only "water pump lubricant additive" makes sense to minimize corrosion and packing wear.

Anti-freeze and special "cooler coolants" don't work better than plain water in low pressure cooling systems.

I agree with the previous posts for newer cars.

[rocketraider]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> Avoid Robert Shaw thermostats (often sold at discount stores such as Auto Zone) as if they were radioactive. Use a Standard, AC-Delco, MOPAR or Motorcraft or similar product.</div></div>

Reatta, I have the 1971 Oldsmobile dealer tech bulletin documenting the factory changeover to the Robertshaw high flow thermostat design, and specifically instructing that any earlier car coming in for cooling system work was to have the Robertshaw design installed. I've used them successfully for many years.

There were and are issues with the earlier Dole flapper type t-stat.

I find most t-stats are made offshore now, either Mexico, Israel or India, and I'm not entirely comfortable with those. I'm pretty sure STANT makes the majority of aftermarket and OE stats now. I dig out NOS stats at swap meets and try to keep several on hand.

[Reatta Man]

Glenn,

Finding OEM at swap meets is probably a great idea. Robert Shaw was probably a high-quality part in its' day, but unfortunately I've found many brands have been bought so they can be stamped on cheap overseas junk.

For example, Elgin watches (previously made in Elgin, Illinois) are now just $5 watches made in China and stamped with a name that a watch importer bought out a few years ago. Ditto with Schwinn bicycles. Remember how Captain Kangaroo used to advertise Schwinn? It was the Cadillac of bicycles, and cost more. Nowdays, no Schwinns are made in the USA; they are stamped with the name bought out by an importer that makes everything in China. Ditto other high-caliber former American names such as Curtis-Mathis. The current merchandise is just a shadow or illusion of its' former high-quality predecesor.

Joe

[FomocoService]

I've used a product called "Water-Wetter" with good results.......

[mrpushbutton]

Frank (original poster) what kind of car are we talking here? (make, model year of manufacture) What shape is the engine in? Radiator? Reatta man has some great advice re: making sure all of the original air-direction items are present and functioning. Adding a bigger, badder fan would be a band-aid for the BIG problem, and that is either a radiator that can no longer dissapate the heat created by the engine or the more likely, the cooling passages of the block and heads are crudded up with rust-shale. If it's a car built before the mid 50's it almost certainly this. Some cars in warm climate states in the south were run mostly on water or water and alcohol, which does nothing to stop corrosion. I have rebuilt engines that were chronic overheaters, would be miserable to drive at highway speeds then get off of the highway onto slower surface streets--a certain overheating scenario, or worse yet, a parade (or the worst of all, the Woodward dream cruise aka "the nightmare crawl"). After dissassembly the cooling passenges looked like a cavern, all kinds of brown rusty-shale crud lining every surface of the cooling passenges, so thick that you could sink the tip of a screwdriver into the crud.

Step one in the rebuild process was to take the block and heads (and all other non-moving parts) to Chem-Strip or other alkline/electrical current process stripper for cleaning, not just the local auto parts store hot tank, which won't get it.

The block and heads came back surgically clean-almost a bright silver color rather than the black/gray color when hot tanked. We paint the inside of the cooling passenges with DP-90 epoxy primer, slosh it around to make sure to cover all of the surfaces.

Do a good rebuild (make sure to rebuild the carb and distributor at the same time), have the radiator cleaned or recored if necessary and put 'er back in a you will amazed at the difference. That engine will come up to the temp of the stat and stay there no matter what you do, no matter what the temperature is that day, and best of all, can handle a parade, or even the Woodward cruise.

All of the band-aid fixes (for me) lump into the "all old cars did that" wives tale category, and those manufactures would have to have been pretty ignorant of mechanical engineering to produce a car that overheated chronically.

As for water being the best conductor of heat: every home chef or home ec student knows that a small amount of salt in a pot of water will make it boil much faster. I know from discussions I have had with cooling system engineers for a big three company that the best transfer of heat is accomplished with a 50/50 mix of water and antifreeze, which is designed to

a) not freeze

transfer the maximum amount of thermal energy

C) retard corrosion of the cooling passenges

And this is best accomplished at a 50/50 mix, 100% antifreeze is not as effective.