Using an Engine Heater in a Diesel Engine for Cold-Weather Starts
Because diesel engines require much higher temperatures to fire the fuel, they’ve always been harder to start in cold weather than gasoline-powered vehicles. To warm things up before the engine can run, a variety of heaters have been developed that keep various parts of the vehicle warm and snuggly even when it isn’t being driven. Some of these gadgets may be on the vehicle when you buy it; others you can buy and install later on if the need for them arises.
If you’re planning to buy a diesel, be sure to ask which heating devices are included in the purchase price. If you live in a cold climate or do much traveling, consider having several devices available for extreme weather conditions. The following sections describe some of your options.
Block heaters: Many diesels come equipped with built-in electric-powered block heaters to keep the engine block warm overnight. You just park the vehicle, plug the heater cord into a heavy-duty three-pronged extension cord, and then plug the extension cord into a 110-volt electrical socket that can handle a three-pronged plug. When shopping, don’t skimp on the length of the extension cord — it can be 50 feet to a socket from a motel parking lot! In Alaska, where a block heater is vital, electrical outlets are built right into some parking meters.
When buying a heater, consult the charts at an auto parts store or dealership to match the wattage of the heater to the size of your engine and the range of weather you expect to encounter. When plugged in, a high-wattage heater will run up your electric bills unnecessarily if you have a small engine or don’t expect the temperature to go below zero very often.
Battery warmers: If your diesel doesn’t start in cold weather and you remembered to plug in the block heater, your battery may be the culprit. Batteries can lose 35 percent of their power at 32 degrees F and as much as 60 percent at 0 degrees F.
This problem has two remedies: You can buy a battery with greater capacity (providing that there’s room for one under the hood), or you can buy a battery warmer. The two most popular models, both of which simply plug into a nearby 110-volt socket, are
The “hot plate” warmer, which simply slides under the battery like a cookie sheet and warms its little toesies.
The “electric blanket” warmer, which wraps around the battery and uses more current than the hot plate version to deal with really frigid situations.
Oil warmers: You can buy a heated dipstick to heat the oil in the engine crankcase — you just trade it for your normal dipstick and plug it into an electrical outlet.
If your heater isn’t able to combat the cold effectively, if you have an electric hair dryer and a long enough extension cord to get it to the vehicle, try turning the dryer on and putting the nozzle into the car’s air inlet duct. The warm air should help your engine warm up faster.
Never use engine-starting fluids to start your engine — no matter how eager you are to get underway. The ether in these fluids can ignite at such low temperatures that you risk a fire or an explosion. Although the containers carry instructions, measuring the “safe” proportions required is just too hard. If you feel that you must use this stuff, have a starting-fluid injection kit installed instead.