The oil light on a ZD30 always takes a few seconds to go out. This is almost certainly because the engine has a high pressure sensor. If it is only a few seconds, I think it's normal operation.
As I said, I have had the high pressure sensor fail twice.
On the first occasion, it the oil warning light came on and stayed on whilst I was driving along at about 30mph. I stopped, switched off the engine and checked the oil. I restarted the engine and the oil warning light went off and stayed off. The problem didn't recur for weeks. On each occasion when the light came on, it stayed on. More often than not, if you stopped the engine and restarted, it was extingsuihed and stayed off.
On the second occasion (I was on holiday about 500 miles from home!!!), the light did not extinguish after starting the engine. It stayed on until I stopped the engine and restarted. If the light did extinguish, it stayed off for as long as the engine ran. It then would either extinguish (or not) the next time the engine started and would stay off (or on) for as long as it was running.
Fortunately, in both cases, I was very confident that it was a sensor problem so ignored it. Nissan checked the oil pressure for me and it is absolutely fine.
Andrew
