Repair And Fix it

Oil pressure in an engine is critical to proper operation and to avoiding irreparable damage to internal engine parts. Electric oil pressure gauges sense the oil pressure inside the engine, then transmit the pressure information to the gauge inside the vehicle. A malfunctioning oil pressure sensor may send erroneous information to the gauge. Test the sensor before you replace the gauge. The sensor screws into the engine block, which connects to the gauge by a wire that is routed through the firewall to the gauge on the dashboard.

Instructions

1

Find the oil pressure specification for your model vehicle and engine size in your owners manual or a vehicle service manual for your car. Find the voltage and resistance parameters for the oil pressure sensing unit in your vehicles service manual.

2

Disconnect the wires that attach to the oil pressure sensing unit. Its usually located on the bottom of the engine near the oil filter. Attach the multimeter that leads to the sensor and then start the vehicle. Check the multimeter and note the voltage and resistance reported by the multimeter.

3

Turn off the vehicle and disconnect the multimeter. Connect the potentiometer to the oil pressure sensing unit by connecting one lead to the blue and white wire on the sensor and the other potentiometer connection to the ground connection on the frame.

4

Set the potentiometer to the resistance (in ohms) as specified by your owners or service manual. Start the vehicle. Check the reading on the potentiometer and note the resistance. Turn off the vehicle, disconnect the potentiometer and reconnect the leads to the oil pressure sensor.

5

Replace an oil pressure sending unit that returns values outside the acceptable range for your model vehicle. Replace the electronic oil pressure gauge if the sending unit tested within acceptable ranges.

When you look at the dashboard of your car, you see several different types of gauges. While youre likely familiar with speedometers and fuel gauges, you must also pay attention to the other display panels in your car. These gauges keep you aware of how your car is functioning and when it needs maintenance.

Speedometer

Standard on all vehicles, speedometers measures your rate of speed in miles per hour. Nearly all automobiles use electronic sensors that determine the wheel speed and then send that information to the speedometer. Since speedometers calculate your speed using wheel speed, the size of your wheels will alter the accuracy of your speedometer. For example, replacing your standard tires with larger tires will make the speedometer think youre traveling slower than you really are. If you decide to alter the size of your tires, have a technician calibrate your speedometer to the new size of the tires. Recalibration requires specialized equipment.

Fuel Gauge

Using a device called a potentiometer, fuel gauges alert you to how much fuel you have in your gas tank. When the needle of the fuel gauge points to the "F," you have a full tank. When the needle points to "E," you usual have 1 or 2 gallons of fuel left in your tank. Check your owners manual for an exact amount, since it will vary by brand and model. This reserved fuel gives you a little extra time to make it to a gas station. However, do not let your fuel gauge fall below 1/4 gallon, which could cause your fuel pump to become exposed, run hotter than normal and burn out.

Temperature Gauge

Your vehicles engine requires coolant to keep it from overheating or freezing, depending on the weather. The temperature gauge reads the temperature of the coolant in the engine. Rather than giving you a temperature reading in degrees, most temperature gauges run from cold to hot with a range in between. If the needle points to the hot side of the scale, your engine is overheating. You must pull the vehicle over and turn off the engine immediately to avoid the risk of damaging your engine.

Tachometer

Using revolutions per minute (rpm), your tachometer tells you how fast your engine is turning. Drivers of cars with manual transmission use this gauge more often than those with automatic transmissions. These gauges employ both colors and numbers to inform you of your rpm. Blue usually signifies a low rpm, while red signals a dangerous rpm. The gauge also includes single-digit numbers such as 1, 2 and 3; multiply each number by 1,000 to get an actual rpm reading. If the needle moves into the red zone, your engine is working extremely hard, which can result in poor fuel mileage as well as damage to your engine.