Morris Minor Owners Club

Hi There

Yesterday I discovered that my oil pressure light in the speedometer comes slightly on at slowrunning. Only with the engine hot. (the oil pressure is lower at hot engine) When I accelerate the light switches off.
Now - the car has been standing for a while ( 14 days or so) without driving. Has anyone experinced anything like this .
The engine is in good condition. Oil new. And there is enough oil on.
The oil pressure switch is 2 years old.
Anyone knows what the trouble is ? Is it electrical or mecanical ?
Dont say its the oil pump !!!

Please help - im desperate

cheers
Carsten

If your engine is in good condition then usually this is a faulty oil pressure
sender switch( to the rear of the dizzy). If a new one does not cure it then you really need an oil pressure check with a gauge. This will show if the pressure is too low on tickover and if it gets up to the correct 60 psi when
running.

It's quite normal with an older and therefore worn engine. You could use 20w50 oil - which is a bit more viscous. The real solution is a crankshaft regrind and a new oil pump - but your engine will run as it is for many years to come.

The engine is in good condition. Oil new

What oil did you use? I've had this on a worn engine with cheap 20/50 oil. I changed back immediately to Castrol GTX and that cured it.

Well - there's not much cheaper than Asda 20W50 - at £ 2.74 for 4.5 litres - and it gives me no trouble at all, and 70 psi oil pressure even when scorching hot! You could check the oil pressure relief valve - just to be sure it's not stuck part way open. You say the engine is in good condition - how do you know that ? You could fit an oil pressure gauge - it's the only extra gauge worth fitting - but it may just give you sleepless nights. Ideally you should have 10 psi pressure for every 10 mph in top gear - up to 60 or 70 psi depending if you have boosted the relief valve spring, or not!