Morris Minor Owners Club

Hi everyone

I have recently fitted new conrod bearings and pistons/rings. Before I did this the oil pressure was taking some time when warm to build up, from cold it was okay. Since rebuilding it's the same, however i get around 55Psi cold and 30 when warm at idle and 45-50 on a run in top gear. When switching off the engine the light takes some time to go back on. I have cleaned the sump/strainer etc so no problems there and changed the oil pressure switch, it's had a new relief spring and plunger too. Does this sound like a worn oil pump?

Your hot oil pressure is 'ok' but not fantastic - even so I think the pump will be ok. I would add a packer under the relief valve spring (a short 1/4" unf bolt works well) to raise the pressure to ~ 65 psi cold. Could it just be a sluggish gauge ? Possibly caused by a pinched/kinked pipe ?

No probs there I even removed the gauge to see if that was the problem, the light still remains on for longer than it should. It's very odd indeed

As far as I am aware it is recommended that the oil pump is changed when rebuilding an A Series engine.
Also did you replace the main bearings, if they are worn you could have more clearance