Lurch has had oil temperature and oil pressure gauges fitted as it is nice to know what is happening inside your engine.
The other week I noticed that the oil pressure gauge was reading it's maximum.... 100psi - this does drop a bit when the engine is idling but not a lot. So out come the repair manual. High oil pressure reading can be damaging.
Oh dear, this means I need to do something before something else breaks. Now as it happens Lurch was due an oil change after going to Holland and back so I took the opportunity to read a bit more and discovered my engine has the late type III oil pump and oil bypass valve based on the "mushroom valve" rather than using a "Barrel valve" as mentioned in the repair manual.
So as high oil pressure is due to some thing (barrel valve, mushroom valve) sticking in the closed position I decided to put an oil flush into the oil before doing the oil change. The one I purchased was from Tool Station (you can look them up). Requires you to run the engine at idle for 5 minutes before changing oil and oil filter. Whilst oil was draining I took the oil pump mushroom valve out and cleaned it and then the oil bypass one which is under the oil pressure switch. Life is easier if you have a magnet on the end of an extending rod to get the mushroom valve out. Cleaned everything I could.
Put it all back together, filled the crank case with oil.
Started the engine and my oil pressure is back to what it should be.
Moral of the story is: Having the gauges helps. Without them I would have been none the wiser to the high oil pressure as the oil pressure light was off.
Maybe some one needs to design an oil pressure switch which has two settings: One to say you have "enough" oil pressure and then to go on to light up again if you have too much oil pressure - only issue I can see with that is how would you know if you had too little of too much oil pressure? Simple I say... two different lights. When you have low / no oil pressure you get the standard RED light. Then if you have high oil pressure it turns on a different light.