09-03-2023, 04:27 PM
Thanks for all the suggestions.
I hadn't previously considered the pressure relief valve, but not properly shutting off would presumably explain the symptoms, especially as revving it quite hard did result in the pressure coming up to around 1/2 what I normally get when the engine is cold.
I'm assuming this would be because at high revs enough pressure is generated by the pump to give a reading on the gauge even if the ball doesn't actually seat properly.
I don't think it could be the vanes sticking in the pump as then I guess there wouldn't be any pressure and also centrifugal force would be assisting the springs once the pump is rotating.
I also don't think it's likely to be water in the sump as the oil level hasn't increased and presumably any water would be coming from the block and I'd have thought I would have noticed something that serious. (The car was actually running fine when I last had it on the road).
I haven't actually done any further investigation as I don't have much room in my garage and working on the drive wouldn't be much fun in this weather.
I'm certainly hoping it's the pressure relief valve as that seems the least difficult / costly think to put right. Just a pain to get at with the engine in situ.
John.
I hadn't previously considered the pressure relief valve, but not properly shutting off would presumably explain the symptoms, especially as revving it quite hard did result in the pressure coming up to around 1/2 what I normally get when the engine is cold.
I'm assuming this would be because at high revs enough pressure is generated by the pump to give a reading on the gauge even if the ball doesn't actually seat properly.
I don't think it could be the vanes sticking in the pump as then I guess there wouldn't be any pressure and also centrifugal force would be assisting the springs once the pump is rotating.
I also don't think it's likely to be water in the sump as the oil level hasn't increased and presumably any water would be coming from the block and I'd have thought I would have noticed something that serious. (The car was actually running fine when I last had it on the road).
I haven't actually done any further investigation as I don't have much room in my garage and working on the drive wouldn't be much fun in this weather.
I'm certainly hoping it's the pressure relief valve as that seems the least difficult / costly think to put right. Just a pain to get at with the engine in situ.
John.