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Coolants

Jim Halderman

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Jim Halderman

Former flat-rate technician and instructor and a business owner. Author of many automotive books and lives in Dayton, Ohio.http://jameshalderman.com

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Topics to be Discussed

Engine coolants- Purpose and function Water (1/2 of the coolant)Coolant TypesCooling system testingCooling system service

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What is Coolant?

Coolant is a mixture of: 1. Water (50%)

2. Anti-Freeze (ethylene glycol-about 93%)

3. Corrosion inhibitors (additives)

Water: 50%

Ethylene Glycol: 47%

Additives: About 3%

Coolant

Need to know

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Additives

The major additives:

1. Reduce corrosion

2. Buffer (control) pH

3. Add color (dye)

Need to know

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Water

Water is the principal ingredient and:

1. Is inexpensive 2. Is a very efficient heat exchange fluid 3. Has excellent thermal conductivity 4. Has a good specific heat 5. Freezes at 32°F (0°C) 6. Boils at 212°F (100°C)The water used in coolant must be clean &

pure.

Need to know

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Good Water

The American Society for Testing and Materials (ASTM) standards for water quality include:

Chloride <40 ppm Sulfate <100

ppm Calcium <100 ppm Magnesium <100 ppm Total Hardness <170 ppm pH Range: 5.5—9.0 Iron <1 ppm

Nice to know

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Freeze and Boil

Pure Water 50/50 Anti-Freeze/Water

70/30 Anti-Freeze/Water

Freezing Point

0° C (32° F) -37° C (-35° F) -55° C (-67° F)

Boiling Point 100° C (212° F) 106° C (223° F) 113° C (235° F)

Need to know

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Ethylene Glycol (EG)

Ethylene glycol is the base antifreeze used in every OEM factory fill. The additive package will vary.

Need to know

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Propylene Glycol (PG)

• Only sold to the aftermarket

• Not recommended for use by vehicle manufacturers

• More expensive than EG, Increased cost is $/gallon

• Still toxic but is not as sweet as EG

Need to know

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Embittered Coolant

Embittered = tastes awful

Embittering agent is required (denatonium benzoate, 30 ppm) Required in California and Oregon since 2004 but not included on the label.Need to know

Bittered States

At this time, 7/20/10, 12 states require antifreeze with a bittering agent: dentonium benzoate. They are:

4 states: Illinois, Massachusetts, New Hampshire, and Ohio are working on a similar rule.

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IAT (Usually Green in Color)

Inorganic Additive Technology (IAT) antifreeze can contain:

• Silicates (possible abrasive dropouts)

• Phosphates• Borates

Need to know

IAT is considered obsolete and can cause early failure of ceramic-phenolic seals used in newer water pumps.

14Need to

know 14

IAT

Inorganic Additive Technology (IAT) is the traditional green coolant used in most older vehicles. This solution offers fast-acting corrosion protection, but the additives are quickly consumed, exposing the cooling system to possible corrosion problems if not changed regularly.

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OAT (Usually Orange)

The downside of OAT is it is not compatible with other types of coolant (IAT and HOAT). In fact, Ford, Chrysler and others say to not use this type of coolant in their newer models.

Organic Acid Technology (OAT) is the formula found in DEX-COOL®, and is usually the antifreeze/coolant of choice for GM, VW, and many Japanese/Asian vehicles. This formula is engineered to offer long-life corrosion protection.

Need to know

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OAT-continued

NAPS=nitrates, amines, phosphate and silicate free

Nice to know

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OAT=DEX-COOL is one brand

Nice to know

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DEX-COOL’s Unique Formulation

• DEX-COOL uses Ethylhexanoic Acid (2-EH) as a corrosive inhibitor

• 2-EH is prone to damage plastics like Nylon 6.6 used in intake manifold gaskets and radiators

• G30 OAT and Peak Global OAT do NOT use 2-EH

Nice to know

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GM DEX-COOL Problems

Class action suit; GM may have to pay for intake gaskets on V-6s (V-8s still being determined)

Brown Gunk on radiator cap

Need to know

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Rust in Engine

• DEX-COOL + Air= rust orDEX-COOL + core sand = Brown gunk

Need to know

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DEX-COOL Concerns

• Root cause= air entering system

• Check cap replace cap

• Air causes ‘Brown Gunk’

• Rust then causes blockages

Need to know

Dex-Cool & OAT that meets GM Spec.

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Prestone markets an OAT antifreeze (Extended Life)

“compatible with ANY antifreeze/ coolant” that meets the GM Dex-Cool spec.

It is less expensive than Dex-Cool-labeled products because of no-royalty cost.

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HOAT (Many colors)

Hybrid Organic Acid Technology (HOAT) is found in newer Ford, Chrysler and Mercedes vehicles. Said to use the very best aspects of both IAT and OAT, HOAT is a very protective, long-life coolant.

Need to know

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HOAT=Red; Pink; Yellow or Blue

Nice to know

POAT Coolant

• Phosphated Organic Acid Technology (POAT)

• Dark Green in color• Used in Mazda-based

Fords (2008+)• same as Mazda FL-

22 • $34.95 per gallon

Ford Motor Company & E-OAT

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The E = European, low silicate and phosphate free

•Ford of Europe has validated Dex-Cool and uses it with no problems.

•Ford of U.S. has reengineered all of their new engines (No- Cavitation water pumps and no-silicone rubber or Nylon 66) to work with this formula.

Ford/Mercury Coolant

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The 1999—2001 Cougar used a OAT Dex-Cool clone, but had issues with water pump cavitation.

Pre 1999 99—01 2002 2003 2004

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Coolant Summary • Ethylene glycol - Most ethylene glycol coolant is any color and contains about 93% ethylene glycol

plus water and additives.

• Propylene glycol - less harmful to pets and animals because it is not sweet tasting, although it is still harmful if swallowed.

• Organic acid technology (OAT) antifreeze coolant – This type is ethylene glycol based but it does not contain silicates or phosphates. It is usually orange. DEXCOOL is an OAT coolant.

• • Hybrid organic acid technology (HOAT) – This orange, green, red, blue or yellow coolant is an

ethylene glycol based coolant similar to the OAT- type antifreeze as it uses additives (a low amount of silicate)

• VW/Audi pink - Most of these coolants are HOAT (ethylene glycol-based with some silicate and contain an organic acid) and are phosphate free.

• Asian red – This coolant is ethylene glycol-based and is silicate-free, yet contains phosphate.

• Mercedes and Ford yellow – This conventional ethylene glycol coolant has low amounts of silicate and no phosphates.

• Mercedes Lifetime – Very expensive, can be drained, filtered and reused.• Korean or European blue – This conventional ethylene glycol coolant has low amounts of silicate

and no phosphates.

Nice to know

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Replacement Antifreeze

The best choice is to follow the vehicle manufacturer’s recommendations

OR

you can follow the recommendations of reliable antifreeze manufacturers

Need to know

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Passivation

• Passivation= is a chemical reaction the takes place between coolant additives and the metal that it protects

• Takes a few days or few weeks • It creates barrier between the metal and corrosion•  Each chemical package does its own passivation • if you change chemical packages, passivation has to

start over  • It boils down to: DO NOT CHANGE PACKAGES.

Nice to know

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“G” Designations

• G= Glysantin –trade name of BASF. Valvoline (Zerex) in the US.

• G30, G33, G34= non-silicate and phosphate free (DEX-COOL replacement)

• G05 = Phosphate free-low silicates (Asian formula and Chrysler HOAT)

Nice to know

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“G” Designations-continued

• G11=Blue VW used before 1997

• G12=Pink/Red VW 1997+

• G12=Purple VW 2003+

• HOAT formulation; phosphate free

?

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“G” Designations-continued

• G48=Low Silicate and Phosphate free

• Blue Color

• NAP =nitrates, amines, phosphate free

• BMW

?

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Universal Coolant

• Arctic Blend

• Recycool

•Prestone Prime

Coolants that have been formulated to be used in any vehicle

Nice to know

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Color

The color helps us identify a coolant leak. It also helps us identify the additive package.

Should not be used as an indicator what to use-some Chrysler vehicles used HOAT coolant that was green

Need to know

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pH

Substance pH

Hydrochloric acid -1.0

Battery acid 0.5

Lemon juice 2.4

Cola 2.5

Vinegar 2.9

Orange or Apple juice 3.5

Acid Rain <5.0

Tea or healthy skin 5.5

Milk 6.5

Pure water 7.0

Healthy human saliva 6.5 – 7.4

Blood 7.34 – 7.45

Sea water 7.7 – 8.3

Hand soap 9.0 – 10.0

Household ammonia 11.5

Bleach 12.5

Household lye 13.5

Caustic Soda 13.9

pH is a measure of acidity or alkalinity of a solution. Less than 7 is considered acidic. Greater than 7 is considered alkaline.

Alkaline

Acid

Nice to know

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pH Effects

Fresh antifreeze pH= 9 and 11

Used coolant pH= 7.5 and 10

It can also increase electrolysis

( the dissimilar metals in contact with an electrolyte can produce a simple battery)

Need to know

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pH of various coolants

• IAT= 9.0-10.5 new

• OAT= 7.5-8.5 new (G30 and G34 designation)

• HOAT= 7.5-8.5 new (G05,G48,G11 or G12 designation)

Need to know

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pH Tests

pH can be measure using test strips or a meter.

Fairly accurate and costs pennies/test.

Need to know

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pH Meter

This Milwaukee is probably more accurate and cost $30.00.

Need to know

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Corrosion

Corrosion is the “decomposition of metal”

(called rust or aluminum oxide, the whitish material that forms on aluminum components)

Oxide formation:

1. eats away at the parent material from the outside

2. forms an insulating barrier for heat transfer

Need to know

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Metal Corrosion

This iron tube has been ruined by rust.

Need to know

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Corrosion

aluminum oxide, often found on coolant outlet/stat cover

Need to know

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Corroded Water Pump

One of the reasons for the removal of silicates from coolant

Need to know

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Corroded pump can cause:

• reduced coolant flowand an overheating

condition

Need to know

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Cavitation

Cavitation is the sudden formation and collapse of low-pressure bubbles. With gasoline engines, the pressure drop can occur at the inlet of the water pump. These bubbles produce a pitting of the solid metal .

Cavitation

Need to know

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Cavitation Damage

The very low pressure can produce gas bubbles that implode next to a metal surface. The implosion blasts particles from the surface.

Need to know

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Diesel Wet Sleeve Cavitation

The sleeve can vibrate during the combustion stroke producing the pressure drop, bubbles, and metal erosion. Heavy duty coolants contain supplemental coolant additives (SCA) to help prevent this.

Need to know

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Galvanic action

• Galvanic activity does not require an outside source of voltage

• The higher the conductivity of the coolant, the greater the amount of corrosion

Need to know

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Metals

Nice to know

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Bi-Metal Corrosion

Ions move from more active metals to less active metal through the coolant which acts like the electrolyteNice to know

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Electrolysis

Electrolysis requires the use of an outside voltage source.

•When electrical ions move from metal to the coolant, they can take metal atoms with them

• This metal transfer can eat holes in a heater core or radiator.

•Electrolysis holes will usually start from the inside and have a dark coloration. Need to know

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Testing Coolant with a Voltmeter

• This test gives variable and questionable results depending on many factors

• Galvanic=less than 200 mV

• Electrolysis= (engine running and accessories switched on and off)=less than 300 mV. This check can locate faulty ground connections

Need to know

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Radiator Voltage

Connect the negative voltmeter lead to a good ground (this radiator has a plastic filler neck), and immerse the positive lead into the coolant. A reading of 0.300 V or greater indicates corrosion is probably occurring.

Need to know

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Coolant Condition

This “green” antifreeze has a clean, bright appearance. The other types will have a different color but should also appear clean and bright.

A muddy brown or rust-reddish color indicates that corrosion is occurring.

Need to know

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Freeze Protection, Refractometer

A few drops of coolant are placed under the sample window. The technician then holds the unit up to light and looks through the eye piece (right end).

Sample Window

Eye Piece

Need to know

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Refractometer Image

The image will show the amount of freeze protection and is read at the scale at the bottom edge of the shadow. This unit can check EG and PG antifreeze freeze protection and battery specific gravity.

Shadow

Read Here

Need to know

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Freeze Protection, Test Strips

Test strips will change color when they are dipped into the coolant, and the color change is compared to the container.

Test strips are fairly accurate, easy to use, and inexpensive.

Need to know

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Coolant Corrosion Protection

The new test strip color is compared to the color pads on the container to determine the amount of freeze protection and corrosion protection.

Need to know

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Coolant Replacement

1. 15 to 20% remains in the system after it has been drained

2. Fill system with antifreeze first and top off with water

3. Be sure to use the specified coolant

(GM warns not to reuse coolant drained from the system)

(Mercedes has a lifetime coolant, drain, filter, & reuse)

Need to know

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Coolant Replacement-#2

• Check the pressure cap and radiator for faults• Check all hoses and always use coolant hose

Need to know

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Coolant Recovery and Storage

Some shops recycle used antifreeze

Should be stored until picked up for recycling

Notice double containers to help avoid spills

Need to know

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Flushing a Dirty System

1. Drain system 2. Fill system with clean water & chemical 3. Run system to operating temp. (Heater on) 4. Drain system & fill with clean water 5. Repeat until drain water runs clear Any remaining flush agent will upset pH. 6. Fill system with 50/50 antifreeze/water mix 7. Run system to operating temp. (Heater on) 8. Adjust coolant level

Need to know

Caution: If flushing a really dirty system, be prepared to repair some leaks.

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Flushing

Some communities permit draining into sewer. EG and PG will biodegrade. There is a problem however if coolant is spilled on open ground.

Need to know

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Be sure to clean the overflow/surge tank

It should empty if you start draining with the cap in place.

Need to know

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Mix Coolant 50/50 or use premix

?

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Coolant Exchange Machine

Most shops use machines like this.

Coolant drains have become fragile and hard to find.

Need to know

TECH TIP

• Check the freezing Point after service

• Should be -34 degrees F (proper 50/50 mix)

• If higher (i.e. -20 F) this means that there is too much water.

• If lower (i.e. -40 F) this means that there is too much antifreeze

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Always check or replace the radiator pressure cap

The cap can be located on

1. the radiator

2. The coolant recovery reservoir

3. The upper radiator hose

Note the pressure.

Need to know

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Cap has two seals

What will happen if the upper seal fails? What will happen if the lower seal fails?

Upper Seal

Filler Neck

Lower Seal

To CRR

Need to know

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Never open when hot!

What can happen if the cap is removed from a hot system?

Need to know

1 psi will increase the coolant boiling point 2.7oF. A 15 lb. Cap will increase the BP 40.5oF.

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Proper Fill

All of the air must be removed from the cooling system by one of these methods:

• Bleeder screw: lets air escape• Air Lift: evacuates system before fill• Spill-Free Funnel: Lisle #22150• Fluid Exchange: requires special equipment

Need to know

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Bleeder Valves

• Use a clear hose attached to the bleeder valve and the other end in a “suitable” container

• Prevents coolant from getting on the engine and gives the technician a visual clue as to color of coolant

Need to know

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Leak Detection

A good system holds pressure

Tracer dye and some antifreezes glow under UV light

Need to know

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What should Technician's do?

• Check service information for the designated coolant and replacement interval

• Check the coolant appearance and level at every service

• Check the pressure cap appearance at every service• Check the appearance and pH for signs that the

coolant should be replaced before the regular service interval

• Check Freeze Point, pH, and Galvanic/Electrolysis

Need to know

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Typical Questions/Answers

1. Are all green antifreezes the same?A. No-Chrysler used HOAT coolant that was green like IAT coolant

2. Can DEX-COOL be replaced with conventional green coolant?A. Yes, but then the coolant has be replaced every 24 months or 24,000 miles

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Questions/Answers

3. Can coolants be mixed?A. No

4. Is DEX-COOL propylene glycol ?A. No. DEX-COOL and all other coolants are ethylene glycol except one labeled propylene glycol and is never used from the factory

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Summary

• Not all coolants are the same• Not all tap water is OK to use• Premixed coolant usually produces good

results• Check the coolant freezing/boiling point• Check the coolant pH • Always check or replace the pressure cap,

especially on DEX-COOL vehicles

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Contact Information

• www.prenhall.com/automotive

• http://jameshalderman.com

Jim Halderman- jim@jameshalderman.com