- When the ignition is on, the oil pressure indicator receives voltage. As long as there is no oil pressure in the engine, its electrical circuit is closed by the oil pressure switch to ground; at the same time, you see the symbol of the manual oiler illuminated in red.
- After starting the engine, the oil pressure rises with increasing engine speed, the oil pressure switch opens the contacts, and the indicator goes out.
- Cold engine oil is quite viscous. This results in high oil pressure, causing the oil pressure indicator to go out as soon as the engine is started. In a warm engine in summer, the oil is thinner. Therefore, the oil pressure indicator may go out a little later, after increasing the engine speed.
Possible malfunctions
If the oil pressure indicator lights up suddenly during a trip, then this is a malfunction signal.
1. If the light comes on briefly during emergency braking or fast cornering, the oil level is probably below the minimum mark. Before starting the engine, this must be indicated by the oil level indicator on the control device. Check the oil level and top up if necessary.
2. The indicator is on for a long time, you must immediately stop! After that, first check for a short circuit in the green wire from the oil pressure sensor to the indicator: turn on the ignition, disconnect the wire plug from the oil pressure switch. When the engine is not running, the indicator should go out; it is better if an assistant is watching this. If the indicator continues to burn, then the insulation of the wire is broken somewhere and it closes to ground. This is not dangerous to the engine, and you can move on.
3. Typically, an oil pressure indicator indicates that the engine lubrication points do not have the necessary oil pressure. This is usually not due to a defect in the oil pump, but due to a sudden loss of oil. Look, for example, if the screw plug has popped out of the oil drain hole. If a malfunction dangerous to the engine is detected, your Renault should be towed.
4. When the oil pressure indicator is constantly on, the oil pressure sensor is rarely faulty. This can only be checked by replacing the sensor. Temporary control: move the tongue of the oil pressure sensor connector back and forth, it may be loose. Does the oil pressure indicator go out when the engine is started briefly?
5. The oil pressure indicator did not light up when the ignition key was turned! Turn the ignition on, disconnect the wire from the oil pressure sensor and connect it to ground: if the oil pressure indicator is now on, then the oil pressure sensor is faulty. Replace sensor. If the oil pressure indicator does not light up, the wiring is broken, the combination instrument board or the indicator itself is faulty.