Question: My 2003 Dodge Ram 1500 with the 4.7-liter engine has a problem that I can't figure out. The trouble started after I filled the gas tank and added a bottle of STP gas treatment (not right away, but when I had reached approximately half-tank level). The engine would start to miss if I tried to accelerate, and later started losing power (it wouldn't go any faster than 63 mph). I thought I might've gotten water in the tank, so I treated it with a bottle of dry gas treatment and refilled the tank. It seemed better at first, but that didn't last. I then noticed that my fuel pump was making a buzzing/whistling noise. I tried another bottle of gas treatment (the fuel injection type), but it didn't help. When I had the computer checked it showed a CODE 1. The pump is still making noise. The engine runs well when I first start it, but begins to act up when the engine reaches running temperature, and gradually gets worse the more I drive.
| 2003 Dodge Ram 1500 front View
Answer: A misfire (one or more cylinders shutting off), and a lack of power from fuel contamination or not enough fuel pressure, typically produce different symptoms on the road. The misfire is a more abrupt bucking sensation while accelerating, usually caused by a loss of spark or fuel to a particular cylinder. A loss of power from insufficient fuel (total pressure, not one injector shutting down) is a somewhat smoother bogging down of the engine"depressing the gas pedal with a lack of response. Not sure where the oeCODE 1 came from. Code P0016 is the lowest numerical diagnostic trouble code your powertrain control module can display, and this one deals with a crankshaft/camshaft timing misalignment. That noise from the electric fuel pump inside the fuel tank should be the red flag. That, along with a lack of power suggests the best next step is to hook up a fuel-pressure gauge to test fuel pressure and fuel quality at the same time. There are other areas that can cause similar symptoms, so you should also have the trouble codes double-checked with a scan tool.
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