Preparation ensures cold weather starting and running.
Many truckers idle to prevent starting problems on cold mornings. But with fuel only increasing in price and anti-idling laws popping up in many areas, overnight idling is no longer the easy way to operate in winter.
Everything works against diesel engine starting as the weather gets colder. The cold, thick oil slows the engine down so much that a starter that draws 700-900 amps at 70 degrees will draw 1,800-2,000 amps at frigid temperatures, says Bruce Purkey, president of Purkey’s Fleet Electric. A battery that works fine in warmer weather could let you down on the first cold day. Testing your batteries and the cable system that delivers the juice to the starter, and making necessary repairs, will help.
“Nobody ever checks the cables. You can’t just look at them,” Purkey says. You need to do an electrical test. For every 1-volt drop in voltage through the cables, you will lose 30 rpm at the starter.
There are sophisticated testers for doing this. But you can also use a clip-on ammeter and a voltmeter. Voltage measurements will be meaningless unless the engine is cranking and lots of amps are flowing through the circuit. That means you’ll need to get somebody to crank the engine for you while you take measurements. Have your instruments ready so you can read the voltage and amperage before the engine fires. Connect the voltmeter between the bare metal of a battery or starter connection and bare metal on or directly attached to the frame or engine block.
First, measure the voltage at the connection on the starter where the battery positive cable connects. Then go back and measure the voltage at the battery connection, and subtract the lower voltage from the higher one. Voltage drop should not be more than 1-2 volts.
“It’s just as important to check the ground,” says Purkey. Measure the voltage at the ground cable connections, too, in the same sequence. If there is a cable between the starter and a ground strap, and another at the frame or battery box, measure the voltage between both the battery and starter connections, and the frame, and then add the two figures. More than 1 volt between the starter and batteries shows high resistance in the system.
If you get a voltage drop, you might want to clean up the connections with sandpaper or steel wool and reassemble snugly, then retest before replacing the cables. Replace battery cables – both positive and ground – that show a voltage drop.
“When it comes to battery testers, you get what you pay for,” Purkey says. “A $45 hand-held unit will give you a test that won’t mean a lot. Go to a reputable manufacturer like Autometer, Midtronics or Argus Analyzers.”
Such testers are affordable for the serious do-it-yourselfer. Jim Hamann at Argus Analyzers reports that the company has two models appropriate for use on a big rig. The AA400 sells for $299 and the AA500 for $399. Hamann says these high tech testers apply a heavy load for a brief time and use that to calculate the battery’s internal resistance, “the holy grail of battery testing.” This works because batteries fail when something prevents the unit from passing enough current. The unit gives you a percentage figure that tells you how much of the battery’s life is left, Hamann says.
Once you know a battery is bad, replace it right way. The more evenly the load is shared among batteries, the longer you will go prior to having trouble, so “don’t mix and match,” Purkey says. Replace all the batteries in the box unless they are within six months of the same age. Also, stick with the same rating and brand so the performance characteristics are the same. This will pay off in reliability and long life.
Purkey says not to buy just by “CCA” or Cold Cranking Amps because the batteries with the most CCA often have only “half the cycling life.” Talk to your supplier and tell him how you use the truck. If you shut down and drain the batteries frequently, the best choice would be a Group 31, a “dual-purpose battery.” These can tolerate giving up a lot of their charge and having it replaced the next day, yet still have good cold cranking power.
Truckers are so used to 15W-40 oil, considered just about ideal from as low as +14 degrees F. up to well over 100 degrees, that they often forget it’s perfectly OK to run thinner stuff at the frigid times of the year. Detroit Diesel’s Scott Zechiel provides the standard SAE guidelines, which his company accepts as offering effective engine protection. Just dropping the oil grade to 10W-40 drops the minimum temperature all the way down to -4 degrees F.
Some 10W-30 grades are also designed to function well over a wide range of temperatures (approved to +95-degrees F.). Synthetics, such as Mobil Delvac 1, Shell International Rotella T and others like them, says Zechiel, are approved for use at maximum temperatures, as well as all the way down to -13 degrees F.
Cummins’ recommendations are only slightly different, allowing 15W-40 down to 5 degrees F. and 10W-30 to -5 degrees, with a maximum of 70 degrees, though certain 10W-30 oils that meet CI-4 Plus and Cummins CES 20078 can be used throughout the year. Cummins also approves 5W-30 from -10 up to 70 degrees F.
Zechiel points out that “the actual operating conditions may determine the lowest temperature at which the engine will start.” However, a thinner oil will allow the engine to turn faster, which always helps.
One way to start more easily is to install a diesel-fired coolant heater. These have their own water pumps connected into the cooling system so the coolant flows around the heater’s metal jacket and through the engine. The heater is much more efficient than idling to warm the engine because it takes in just enough air to burn the fuel, while an idling diesel takes in extra air.
Using a heater to warm the engine before cranking also eliminates the high stress of cold starts, when oil has trouble getting to the parts.
As the heater warms the coolant, the oil on the pistons and bearings will also warm up. This will allow much faster cranking, which decreases the load on your battery and starter. The faster cranking and warmer cylinders will make the air much hotter during compression, resulting in an instant start.
Checking your coolant
For winterization purposes, the largest issue is freeze protection. Shut down overnight in extreme weather and the coolant in an engine with straight water or the wrong concentration of antifreeze will freeze solid. Because water expands when it freezes, the result will be a cracked cylinder block.
Some silicone radiator hoses will allow water to slowly escape from the system, resulting in too much antifreeze.
Remember, when used almost straight, antifreeze may not even protect the system from freezing. Antifreeze by itself is a very poor coolant; much more than the required coolant percentage will cause critical cooling problems.
Check the coolant concentration with a hydrometer, a precision instrument that costs about $100.
Once you know what the concentration is, adjust if necessary. The ideal concentration is 50/50 unless you live in an area where the level of protection 50/50 provides, (-34 degrees F.) is not adequate. You can use up to 60 percent concentration, which protects down to -65 degrees. To increase antifreeze level, drain some coolant and add straight antifreeze. To decrease, drain some coolant and add de-ionized water or tap water whose mineral concentration meets your engine maker’s standards.
Check your hoses and clamps because cold often produces leaks. Hoses that are soft or cracked should be replaced. Tighten loose clamps or, better yet, get the constant torque type clamps that are spring loaded.
Diesel is subject to gelling and even water-related freezing problems. Also, if you buy fuel in Florida or Texas and travel to Minnesota, your fuel won’t be right for the climate.
That’s why a number of suppliers make carefully formulated additives. An inexpensive can of additive might be cheap insurance against gelling/freezing trouble.
Water is one of the winter problems because it often gets drawn right through the fuel, says Howe’s Lubricator’s Steve Sikorsky, vice president of sales and marketing. As soon as temperatures drop below freezing, that water can freeze. Opening a tank on a summer day after refueling from underground tanks will cause moisture to condense out of the humid air. This forms a water layer on the tank bottom.
Sikorsky recommends looking for a product that demulsifies or separates the water, rather than an emulsifier. He says, “Most engines have fuel/water separators. When you use additives with alcohol, the water gets lighter, won’t drop out. Demulsifiers separate the water from the fuel, breaking it into particles surrounded by petroleum. This enhances the effectiveness of the separator, so the water ends up in the bowl for draining. It also has a non-alcohol deicer, which renders the water harmless by keeping it from freezing.”
He claims fuel flow blocked by ice is just as common as gelled fuel from wax. Use a demulsifier before cold weather to clean the water out of the system.
Sikorsky says that alcohol will lower the viscosity of the fuel, interfering with injector lubrication.
And what’s going to happen with ultra low sulfur diesel? Sikorsky feels there are many variables that haven’t yet been fully explored, and that it will be harder to dissolve the type of paraffin (wax) it contains. Lubricity will be an issue because it must be added by the downstream suppliers to keep it out of the distribution system. That opens up the chance for error. The fuel is inherently lower in lubricity, and with injection pressures on the rise, lubricity is more important than ever.
Jeff Kramer, vice president of sales for Power Service Products, thinks the big ULSD issue is the fact that “blending with No. 1 is going to be obsolete.” Refineries are not going to make a lot of ULSD No. 1, so distributors won’t be able to blend it in with No. 2.
“We’re seeing that ULSD is so different,” Kramer says. “With a shortage of No. 1, truckers need to make sure the fuel is winterized. They need to take the situation into their own hands.” As a result, Kramer maintains that ULSD will need more anti-gel. “Operators will need to be proactive, as much as double treating to properly winterize their fuel in extreme temperatures.”
He recommends reading the label and using 96 ounces to 300 gallons normally, and 96 ounces to 150 gallons under extreme conditions.
The good news? “There is more energy in No. 2,” Kramer says. “A lot of people have been running No. 2 with additives for 20 years. Blended fuel could cost them the equivalent of 30 cents per gallon extra. People using additives have saved a lot of money.”
Kramer also says, “ULSD will have a lot more wax because of the refining process. So, it will require more anti-gel to keep the wax from causing gellation.” He says there used to be a temperature separation between the cloud point, cold filter plugging point and pour point. Now, they have almost merged. “There’s so much wax that once it hits the cloud point, it’s gelled.”
The cloud point typically occurs slightly below the average temperature for the time of year and location, so in cold snaps, you should be careful to treat aggressively.
“Every fuel batch is different,” reports Peter Guerra, vice president of sales and marketing at FPPF. “There are winter and summer blends. The winter blends are created by taking some of the waxes out. Some refiners do everything right.” But not all do.
In those cases, you might need anti-gel additives. Anti-gel puts a charge on the tiny wax molecules so they repel one another, which stops the wax from globbing together. “This prevents gelling from occurring for another 25-30 degrees F. below the untreated fuel,” reports Guerra.
“Current anti-gels will work, and treatment procedures will be the same,” he says, but he does suggest being “more cautious.” That would come down to using a better fuel/water separator. Plus, it’s important to use a dispersant, anti-ice or a water absorber, like FPPF’s anti-gel, which contains an absorber.
Guerra recommends that truckers “put in the additive when the fuel is relatively warm.” In winter, that would mean after a day of driving. “Add the additive first, and then fill the tank. Mixing is critical.”
If fuel is already gelled, you could try a product like Power Service Products’ Diesel 911, a special additive that will “reliquefy gelled fuel on contact,” Kramer says. “You could buy a product like 911 and keep it in the toolbox.”
Get Ready for Winter
Reid Landis, marketing specialist with Webasto Products North America, provides a pre-winter checklist:
For More Information:
FPPF Chemical Co.
Lucas Oil Products
Power Service Products
Webasto Product North America