I seem to recall the idiot oil gauge and the oil warning light are linked but different, with the light signifying pressure below 5 psi and the gauge signifying a pretty mid-scale needle and not much else.
Either way, when I noticed the gauge at zero and the warning lamp on, it was quite a jolt. My first thought was how long had it been like that? Being about five miles from home and in bad weather, I eased the car carefully home, wondering when the clonking sound would start.
Next day it seemed OK and I suspected a temporarily stuck pressure relief valve. Over the ensuing weeks, the 97 XJ6L performed dependably as usual in its roles mi, apart from every so often throwing wild zero pressure signals. I began to notice faint knocking noises - or did I? after a total of about fifty miles of ‘zero pressure’ errand driving I finally got it on the ramp and plugged in a wet OP master gauge where I removed the oil . Result said 80 psi for a cold engine.
My CD ROM is currently not usable, so can anyone figure out which location to find the gauge sender and how to check the gauge wiring?