(Originally posted Dec 2011, updated Sep 2020 and Sep 2022 by Tom Dwyer Automotive Services)
Fall is just ending, but winter is just beginning. No one wants to be left on the side of the road in winter weather! It may make a great story for future holiday get-togethers, but it’s a miserable experience everyone would rather avoid. A well-maintained vehicle is ready for Winter, but many of our clients still worry about tough winter driving and how to be ready. Since many people are driving so much less because of Covid they’ve also asked about any impact of reduced driving on their winterization needs. This month we thought we’d talk about two critical areas of concern for any upcoming Winterization Service: your vehicle’s engine cooling system and the battery/starter/charging systems…
Engine Cooling System
What is engine coolant (antifreeze)?
Some people may not know that coolant and antifreeze are the same thing. It’s made of ethylene glycol to prevent freezing or boiling, and mixed with various other additives. For example, some of those additives provide “reserve alkalinity” to neutralize internal radiator corrosion before it starts.
When should you check your coolant system?
The best time to inspect the overall integrity of the system hardware is when you change the coolant. Our procedure checks belts and hoses for cracks and wear, makes a visual inspection for leaks, pressure tests the radiator and cap, and checks the operation of your heater and defroster. The thermostat regulates the engine coolant temperature and should be changed if the system has been allowed to corrode, it is over 10 years old, it has been causing trouble, or the engine has been overheated. Replacements should be good quality units with the same temperature rating as the original. This is extremely important on late model vehicles with computerized engine controls, where fuel, ignition and emission functions are all affected by coolant temperature.
When should you change the coolant?
New antifreeze is alkaline, usually between 8.0 and 9.0 pH (where 7.0pH is neutral). Antifreeze protects your engine as long as it stays above 7.0pH, but when it drops below 7.0 it starts to eat away your engine from the inside. Most new car maintenance schedules call for changes every three years or 60,000 miles, some professionals recommend every two years or 24,000 miles, and others think later model vehicles with bi metal engines should have yearly changes.
Rather than using mileage or time menus, we think the best way to know if the coolant needs to be changed is to test it, determine the pH, and replace it if needed. As long as antifreeze is changed before the reserve alkalinity is depleted the cooling system should be no worse for wear. If you wait too long, however, you could have expensive internal corrosion in the radiator, water pump, hoses, heater core and engine.
What’s involved in a coolant flush?
When the coolant is changed the whole system should be pressure tested for leaks first, then reverse flushed and refilled. It makes no sense to service a leaking system! The pressure test ensures the hoses and water pump are in good shape and there are no leaks in the system. Once the system is leak proof, we flush and refill the coolant. Chemical cooling system cleaners usually aren’t necessary, and we prefer not to use one unless the system has been badly neglected and is full of lime deposits. Once the old coolant is removed completely, the system should be refilled with a 50/50 mixture of ethylene glycol antifreeze and clean water. This provides freezing protection down to -34°F and boil-over protection to 265°F.
Engine Charging System
How does your charging system work?
Many people think a vehicle’s electrical power comes from the battery, but while the engine is running all of the power for the accessories is delivered by the alternator. The alternator is the heart of the charging system, converting the mechanical energy of the engine into DC electricity to power all the electrical accessories and maintain the battery.
Batteries are actually loads on the charging system, and only supply power when starting the vehicle, when the accessory load (defroster, AC, headlights, etc.) exceeds the alternator capacity, or when the engine is at a very low idle. When alternators fail, vehicles switches to battery power and continues until the battery is dead.
When should you replace your battery?
Alternators are designed to maintain the charge of a functional battery, not to recharge a failing one, so the quickest way to kill an alternator is to put it to work struggling to maintain a failing battery. It not only damages the alternator, but can also cause damage to the starter motor and starter contacts. When alternators are replaced it is critical to make sure the existing battery is in good shape or it can cause the replacement alternator to fail.
Sometimes vehicles won’t start with a failed alternator and low battery, but other times the vehicle starts fine and then fails on the road when the battery finally dies. If you are not sure how old your battery is, have it tested. You should consider replacing batteries over 5 or 6 years old even if it tests OK now.
Most new vehicle batteries are rated for 36 months, and while a small number fail within this period, most will make it 4 or 5 years. It’s rare for original equipment batteries to survive more than 5 years. Preventative replacement is important for batteries, because extremely hot or cold weather will reveal marginal batteries at the most inconvenient times.
What’s involved in battery and alternator service?
Maintenance and service of the electrical system should always start with a careful visual inspection of belts and pulleys, belt tensioners and idlers, battery exterior condition, the battery hold down, and the battery cable connections. Most of these defects would need to be corrected before deeper testing can be done. For example, a discharged battery can’t be tested properly and would require several hours of charging to test it. With a visual inspection performed and problems corrected, actual testing of the electrical system can begin.
Complete electrical testing should include:
- Testing the battery for resting voltage
- Testing the battery for capacity and reserve
- Testing alternator output and diode condition
- Testing the starter for excessive draw and electrical signature
- Testing the resistance of ground circuits
- Voltage drop testing
It is much better to replace a questionable battery than to risk the consequences, but all batteries are not created equal and cheap batteries are not a value. We have tested many brands in the almost 30 years we have been servicing vehicles. We only stock high quality batteries like Interstate and AC Delco for most of the vehicles we service.
What can you do by yourself?
We’ve seen major and avoidable expense caused by battery acid on electrical harnesses and other sensitive electronics near the battery. Battery acid is highly corrosive and can cause major damage to the battery tray, battery cables and power feeds, fuse and circuit breaker holders, battery hold downs, and anything else exposed to it.
If you see fuzzy acid crystals growing on or near your battery, clean and neutralize everything that has come in contact with the acid. Unfortunately, you’ll probably need to replace the battery as well.
Do your electrical and coolant system need service?
A large percentage of vehicles broken down on the side of the road are there because of electrical or cooling system related failures, but these are some of the most basic things you can do to prevent major problems with your vehicle. Checking these systems are standard parts of our comprehensive and seasonal inspections, so if you’ve seen us for either of those services then you’re ready to go. If you’re not sure, give us a call and we’ll tell you the last time these services were done and when they’re due again.
In many cases charging and coolant system failures can be prevented or repaired before a breakdown causes major inconvenience or larger expense, but it requires a careful inspection of the systems BEFORE problems become obvious. You don’t want to be telling stories about this winter’s unplanned breakdown… call us today and drive with confidence throughout the winter!
