hmmmmm, the 1275LS has no oil pressure,had been sitting idle for around 3-4 months, dropped oil and changed filter, started her up and nothing..... had always taken a while to get pressure but never like this.. gauge sits on 0 and light stays illuminated.... thinking it could be the oil pump knackered... are there any better options other than standard pumps? any one else experienced this?????
cheers...

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1978 1275 LS silver 3rd palce mini Oz50 LS,SS,GT Class
1970 MORRIS MINI K 1100 3rd place mini50 pre '71 Class
Rover BBQ.....

Firstly the oil pump sucks and pumps from the sump so any rubbish that is in the sump is going to score the oil pump and yes - given dirty oil they do get old very quickly. You never do an engine rebuild without changing the oil pump. Having said that oil pumps are not expensive to buy - plus or minus $50.

You do hve to take the engine out to change a pump and you will have to take off the clutch , clutch housing etc. So you would also need clutch housing gasket and a clutch oil seal.

But...... perhaps all is not lost, you can prime the oil pump while the engine is still in. Take off the oil pressure relief valve - thats the big nut under the oil line to the filter. Inside that is a spring and a bullet shaped bit of metal. Give them both a good clean and the tube in the block that they came out of. Then with a oil can - squirt oil deep into that recess, leave it a couple of seconds to settle and repeat the process until it doesn't settle any more. Put the oil relief assembly back into place and tighten the nut. Start the motor and let it idle to see if pumps up pressure and kills the light. DO NOT REV THE MOTOR and do not run the motor for more than a minute or so.

If the light does out and the pressure does come up then you are doing well. Perhaps the oil has thickened with time and is hard to suck up. CHANGE IT - perhaps the oil is too thin and simply seeps out of the oil galleries - Change it. Perhaps your bearing are to worn to hold enough oil pressure.

But what ever the reason do not rev the motor or run it for long without oil pressure - that will quickly ruin a motor or even cause it to snatch a bearing and ruin the block.

Could be your oil pressure relief valve stuck open?

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850 Morris Mini
Morris Mini Traveller
Mini sports Sedan

Try removing the the oil pipe that runs from top of the engine that runs to the oil filter and use an oil can to pump oil back to the pump through the hole untill its full and then put the pipe back on and wind the engine over, also make sure the oil filter is full of oil also.

After the time you have left the engine sitting the oil pu,p will of drained and with the oil and filtter change the pump will not pump up without priming it, just like a new engine

Jon

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Roundies and Clubbies(except vans) are both ugly that is why I have Midas and a van
1293 Mini Midas Bronze,1275 Clubman van

is there sumthing wrong with the sender unit or has the wire fallen off??

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- '74 Clubman Ute project

The sender unit
Good god yes - check the obvious first - I had forgotten about that

I have had the same problem before with my car , had sat for maybe 3 months
without being started ,cranked it up , no oil pressure ( shat myself, thought here we go ,engine out, re-build big buck's).rang a mate,he told me the same as what Mike and Jon advised oil pressure fine, it appear's that oil had drained back from pump, just needed priming.

Sounds like the pump needs priming due to an air lock. My Cooper S does this every time I start it (about every 12 months )

Does it have an oil cooler?
First thing is how long did you run it with the light on?

I would remove the spark plugs so that it spins over easier.
Follow "feralsprints"s advise about priming the pump by removing the pipe.

This means that it can't be a wire fallen off because it is a light and a gauge.

I've seen this problem when people run too light an oil. Barney's previous owner was running Valvoline running in oil in the 1098 because he had a drum of it, it's about 20 grade I think. If he left it more than a week it wouldn't prime.
Since filling it with 20W/50, no problem.
So if it's an old engine, don't run thin stuff in it...

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.