The oil pressure warning lamp, which comes on when the ignition is switched on, should extinguish at idling speed.
It is operated by a switch on the oil pump body.
If the lamp flashes, or remains on, check the oil level in the sump and ensure the filter is not clogged.
If these are in order, check the electrical system tor faults. See Chapter 10.
If the lamp comes on when slowing down from high speed,
again check the oil level and the filter. lf these are OK, the main bearings or big-end bearings may be worn, or the oil pressure relief
valve or oil pump may be faulty. Have the oil pressure checked with a guage. If the pressure is low, overhaul the engine.
To remove the switch, peel back the rubber cover and slacken or remove, as necessary, the terminal screw.
The oil should be drained before the switch is removed, so that the switch threads can be cleaned properly. Unscrew the switch.
On refitting, clean the threads of the switch and the oil pump body, apply a thin coat of sealant, and refit the switch.
Tighten it carefully to the specified torque wrench setting; do not overtighten it or the switch may be broken and the pump body cracked.
Tighten the terminal screw securely, apply a coat of WD40 or similar (see Chapter 10)
and refit the rubber cover, ensuring that it seats fully.
27.4 Oil pressure switch is screwed into pump body - ensure it is completely waterproofed