Operating a motor vehicle in cold weather places demands on its systems unique to the season. It’s up to us, the automotive professionals, to assist our customers in ensuring that their vehicle is ready for the challenge.
Cooling system
Near the top of the list in preparing a vehicle for winter driving is a check of the cooling system. I’m sure everyone reading this knows that it is important that the mixture ratio between the concentrated coolant and water is maintained between 40 percent to 60 percent. This can easily be checked with a specialty test strip or most accurately, with a refractometer.
In addition to the mixture ratio, it is equally important to check the pH, or acidity, level of the coolant. This is an indicator of the health of the additive package that every coolant has. These additives, or “inhibitors,” are used to extend the life of the coolant, lubricate cooling system components and protect the components from rust and corrosion. In this case, the use of a specialty test strip is required.
If the coolant passes the pH inspection but fails the mixture ratio check, you can correct the condition by adding the proper coolant concentrate or deionized (or distilled water, if deionized is unavailable) to the system. However, even if the mixture ratio is spot on, if the pH is out of specification, the cooling system must be flushed, and the coolant replaced with a fresh fill — regardless of time or mileage.
Also, a word on the water you use. Never use tap water to service the cooling system. Tap water has minerals and other contaminants that can quickly deplete the additives, resulting in a coolant mixture that can no longer protect the system. That leads to premature failure of water pumps and heater cores, and erosion in the passages. Tap water is also typically aerated to improve the taste. Air may make the water attractive for drinking but introducing air into the cooling system is always a bad idea.
Finally, and probably obviously, check the level of the coolant. Coolant doesn’t evaporate, and if it’s low, that means there’s a leak somewhere. The leak can be external or internal and both can be a challenge to pinpoint, especially on today’s multiple flow path systems. Consider using a dye to help identify external leak sources and specialized techniques for identifying internal issues.
Battery
Among the most popular wintertime complaints, usually occurring in the middle of a winter blizzard, is the call from the customer that “my car won’t start.” We all know that available voltage potential at the battery is reduced as the thermometer falls. That’s why performing a battery and charging system test is so critical before the cold weather hits.
One of the very first measurements we need to take when assessing the condition of the battery is the Open Circuit Voltage (OCV). The OCV indicates the State Of Charge (SOC) of the battery and must be more than a specified level before accurate testing of the battery can be done. But is your OCV measurement accurate? And what minimums are acceptable before proceeding with further tests?
Davis Knauer, vice president Automotive Battery and Diversified Products Engineering for East Penn Manufacturing says, “Accurate testing requires a minimum State-of-Charge level. A rested open-circuit voltage (that means it’s been over 24 hours since the battery has been exposed to charging) of 12.4 minimum is required before load testing.”
Where you test can also have an impact on your test results. If you just brought the car in and connected your meter or handheld battery tester to the battery’s cable ends, your test results may be suspect. This is especially true if you’re trying to test a remotely mounted battery using the jump points under the hood. If techs test the battery using the underhood booster terminals, this may lead to falsely diagnosing a battery as bad. Additional resistance caused by the length of the cable can often result in inaccurate battery diagnosis. If a remote-mounted battery is tested and fails, repeat the test directly at the battery to confirm if it’s an issue with the battery or if the issue is elsewhere.
But even then, most experts agree that the battery can’t be condemned in the car. “Testing failures in a vehicle must be confirmed after the battery is removed from the vehicle. Readings made while connected in the vehicle can be affected by poor connections, active loads and effects from recent operation,” added Knauer.
Once you’ve determined that the SOC is enough to proceed, the gold standard for testing is a load test conducted according to the Battery Service Manual published by BCI (Battery Council International). A load of half the CCA rating is applied for 15 seconds. The voltage must not fall below a limit that depends on the core battery temperature at the start of the test. The battery must initially be at least 75 percent charged, which correlates to a well-rested, open-circuit voltage of 12.4 or higher. Remember what that means? It’s been over 24 hours since the battery has been exposed to charging!
Conductance testers that correlate to BCI standard load test results are an alternative to the traditional load test. You may trade some accuracy for speed, but it is generally worth the time saved. The user must be sure to connect it properly, avoid putting in incorrect data to the tester (which means to first properly identify what kind of battery it is — conventional or AGM), charge the battery properly before retesting when requested by the tester and reconfirm failed results obtained in a vehicle after the vehicle connections are removed from the battery terminals and the terminals are cleaned. Proper connections to side or stud terminals require that charging adapters be used properly.
No matter what testing method you use, if the battery is marginal, recommend its replacement. Be sure to replace it with one meeting the OEM specifications and, if needed, let the appropriate control module know you replaced it!
Wiper blades and washer fluid
You wouldn’t think that wiper blades would come up as part of a winter inspection, did you? But if you live in any part of the U.S. that sees snow, you know that most of your customers use the wipers to clear their windshields rather than get out and use the scraper. Of course, the wiper blades were never designed for that purpose and quickly become ruined. Later, when the glass is just smeared or dirty from the road salt that has been laid down, the blades can only smear the mixture across the glass instead of cleaning it.
Of course, that also depends on whether there is any washer fluid in the reservoir. I made a habit of topping off the reservoir whenever I serviced a vehicle. And nearly every one that came in was very low or empty. It’s one of those things a customer thinks about when they need it and forget about when they don’t.
Using a washer fluid designed for automotive use is also a great way to protect the system from freezing.
These are just a few of the inspection items that need a little extra attention paid to them as we near another winter season. I’m sure you can add a few of your own. And taking the time to inspect these little things is one great way to show your customer that you care about their car — and their business.
