Converting to Ethanol
Q: I have a 2002 Dodge Dakota with the 4.7-liter V-8. The engine has only 38,000 miles on it, so it's barely broken in. Dodge is making a 4.7-liter V-8 for some of its vehicles, which can run on ethanol. Is there a conversion for my 4.7-liter to make it ethanol compatible?
A: Ethanol is an alcohol-based alternative fuel typically derived from renewable sources such as corn, barley, or wheat. E85 is a mix of 85 percent ethanol and 15 percent gasoline for use in cars and trucks factory-equipped with an FFV (flexible-fuel vehicle) option and available at a growing number of pumps in various regions across the U.S. E85 produces lower amounts of certain harmful emissions and also can reduce the amount of imported petroleum-based fuel burned. But a gallon of E85, while comparably priced with regular unleaded, generates less energy than a gallon of straight gas, resulting in a shorter range and fewer mpg. Flexible means just that--FFVs also can run on standard grades of gasoline at the owner's discretion. Factory-installed FFV packages include upgraded fuel pumps, lines, tanks, and additional fuel-system components modified to tolerate the corrosive properties of alcohol-based fuels. Larger injectors are installed to disburse the necessary higher volume of fuel. Most systems require a fuel sensor to determine ethanol content and PCM calibration to adjust the air/fuel ratio. Many FFV owners are unaware of their vehicle's fuel-flex capacity and run solely on gasoline. There's usually an FFV notice on the fuel-tank filler door, or a dealership can determine E85 compatibility by the VIN. For 2002, Dodge produced only the 3.3-liter V-6 FFV Caravan for retail sale, so your Dakota isn't FFV-equipped. Currently no EPA-approved FFV conversion kits are available, partially due to the minimal expense of the factory option, and perhaps the higher focus on additional alternative energy sources, as seen by the growing production of hybrid-electric vehicles and aggressive early development in hydrogen fuel-cell technology.
Clean-Car Gremlins
Q: My 2000 Oldsmobile Bravada wouldn't start after I had it washed. The car-wash attendant jumpstarted it, and it lit right up. Soon after that, the air-conditioner quit working. When the controls are turned on, it blows hot air. I traced the problem to something under the hood and changed out fuse #10, in case it had blown. I know there's a relay for the A/C and the compressor's cold, but I'm not sure what to do at this point. If the unit's low on Freon, would there be any warnings before the unit blows hot air?
A: I can't see the car wash or jumpstart being a relevant factor. Needing a boost is a sign of a bad battery or a charging-system problem and shouldn't have an effect on air-conditioner operation. That the compressor is cold and the air coming out of the A/C vents is hot suggests a temperature-control fault in the system. The temperature knob on the manual air-conditioning control panel powers an electric temperature-control motor. The motor positions a valve that directs air through the air-conditioning evaporator and/or the heater core, therefore managing air temperature out of the ducts. There may be a problem with the controller, the temperature motor, the valve hanging up, the electronic climate-control module (if equipped), or there may be a wiring problem. But the first thing to check is the temperature-control knob itself. It's plastic and has a habit of cracking right where it attaches to the switch in the control panel. If it cracked while turned all the way to hot, you can turn the knob back to cold without actually moving the switch, therefore it would remain in hot mode. Pull off the knob and inspect for cracks. You shouldn't have to replace the entire control assembly to get a new knob. If it checks out okay, a qualified technician can accurately pinpoint the problem.