10 replies to this topic

[Bigremi]

Greetings all,

Long time no chat, I've had my fair share of issues with my mini ( A  '78 1275* clubman) but they've all come down to old pipes or english electrics.

 

https://ibb.co/v1rkwxq

https://ibb.co/CQyrC9F

 

This current problem I am having is different:

The car will start and run absolutely fine no unusual noises (may or may not have driven a decent distance on 0 pressure)
From start up the oil pressure is reading 40ish psi (a little lower than the standard 50-55)
After 20 seconds the pressure will drop to 30, then 20 ect, so that after 2 minutes i have between 7 and 0 psi, always 0 by about 5 minutes.

 

Troubleshooting:

Originally i believed this to be an electrics problem with the sensor, so a new battery has been installed
Topped up the oil to the max

Cleaned the pressure relief valve (with the valve removed we cranked the car and oil came out but not at high pressure)

Attempted to prime the oil pump, pouring oil into the inlet and pushing the car in gear (definitely moving oil)
 

I have ordered another oil pressure sensor just incase, I will update this with results once it arrives

 

My question to you,
Is there anything else I can test without tearing the engine out and having a look at the pump directly?
Is there anyone in the west midlands i could take it to to have a look? and potentially replace the pump?

Normally i would be happy to mess around myself and sort it out, but i have a strict deadline of having the car running reliable by the 2nd of April for a road trip.

Cheers for any help,
Remi

[nicklouse]

The only thing that come to mind is oil pressure relive valve. Yes it won’t pump out at high pressure the pressure is made by the bearings (a restriction). Check it again. 
 

or your bearings are shot.

[Cooperman]

It sounds like a bearings or oil pump problem.

You get some pressure at initial start up when the oil is at its thickest and as it warms the oil effectively thins and you end up with virtually zero.

You can 'fiddle about' with it all you want, but if the pressure is that low and you continue to run the engine you will simply do a lot of damage and the only real way forward is to pull the engine and inspect the crankshaft bearings and oil pump.

It is doubtful that it is the pressure relief valve.

Every engine I have ever seen with that problem has needed a bottom-end rebuild, usually with a crank re-grind, plus a new oil pump. At that point it is usually best to hone the bores and fit new rings, a new water pump, etc.

[bluedragon]

If you really doubt the accuracy of your oil pressure gage, plumb in a mechanical one for temporary purposes.

 

An engine oil analysis seems like it would tell you if you had really been running at low to 0 oil pressure - should be plenty of bearing alloys floating around in the oil that the analysis will pick up.

 

 

Dave

[Bigremi]

Hello all,

 

Thank you very much for all your advice,

I fitted the new sensor today, and the oil pressure is now reporting as absolutely perfect.

I still have more testing to do before taking the car on any long trips but it seems the sensor was just completely shot

[DeadSquare]

Thanks for coming back and telling us the good news.

 

It is information like that, that is really useful, as it could save an owner a lot of time and wasted money.

[Ethel]

Maybe it was a heat/viscosity thing, thinner oil getting in & equalising the pressure across the sensor.

[sonscar]

I had similar hopes for my Triumph TR7,but sadly the engine is dying.Do you think Mini engines are expensive to repair?At least the Mini has some value when finished.Steve..

[Cooperman]

You sure 'lucked out' there. Good news for you.

 

Ah, the TR7. My wife had a new one in 1977 - a collection of spare parts in close formation. Quality control, what quality control?

[Bigremi]

Final update for you all,

Found out the sensor was full of oil, not a clue what that would do to the sensor but can't imagine it was any good. Probably what tmf team said.
Again thanks for all your help

[DeadSquare]

You sure 'lucked out' there. Good news for you.

 

Ah, the TR7. My wife had a new one in 1977 - a collection of spare parts in close formation. Quality control, what quality control?

 

 

Poor old Triumph.   ...   My brother-in-law had a Stag, with the infamous "air-cooled" V8