Totally losing my mind right now for the third time I’m having oil pressure problems This time it is a bit different tho, it is very slow to get up to pressure as in 30-60 seconds to get to 40 PSI. What could this be from? When I put it back in tonight it was sitting on 60PSI all nice after 15km driving started dropping to 50PSI then slowly to 40PSI and that where it is now.

I’ve changed the relief vale from a STD slide, to a ball bearing, back to a slide with a bolt in the back of the spring to give more tension and no different at all.

I’m more then over this thing now, and pulling my hair out with what it can be... It shouldn’t be this hard. My last motor never ever had any problems with oil pressure, even with all the abuse we all gave it (you know who you all are ) this one that I have tried to do every last thing right with it, didn’t scrimp with anything and can’t get it to work ..

Throw as many questions as you can think of to give me some more ideas of what it could be.

Thank you from a very tired, cold and frustrated Nathan.

How sure are you about the state of the pump?

When i've re built engines that are low on pressure the pump internals look like a reccord.

Gearbox crunchies, khana 1st to reverse bad....

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Dean Hutton's first car was a Mini.

Well the pump that is in there is the new one I throat I was having trouble with the shaft in the other thread. So it is a new pump with an old shaft in to it. I know what you mean about them looking like a record, this one doesn’t. But can’t rule the pump out.

Tomorrow I will redo all the tests I did last time.

This is the first two times in case people haven’t seen.
http://www.ausmini.com/forums/viewtopic.php?t=54835

Nathan.

Don't feel alone Nathan your not on own with this particular problem i have a mate that has a brand new 1275 engine that has started to do the same thing, it's running 40-50 hot, 20 at idle, it hasn't totally lost pressure altogether as such , so far he has changed the oil, spring and relief valve, he is going to give it a run today to see if it helped. I was telling him yesterday of your problem and the finding's with the pump so i will keep an eye on the subject with interest.All i can say is BLOODY MINI'S, they can test you.

Colin.

After all the work on the pump you may be able to assume that that is OK. A few other obvious thoughts....

1. Is the gauge correct? Electrical or capillary - maybe an air bubble in the capillary??

2. New filter - for a few bucks try changing the filter in case it's restricting the flow too much.

3. What oil are you running - not too thin? You said it dropped after running and stayed down - was the engine still hot or did it have a few hours to cool down and let the oil thicken back up?

4. On another thread you said you changed to another pick-up - it doesn't have a hole or not fitting flush and allowing some air to be sucked up.

5. What were all the bearing clearances? Maybe wrong size bearing somewhere letting too much oil out of the pressurised system?

6. what does it look like is happening under the rocker cover? Small air bubbles (see 4.) - lots of oil (see 3.)

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That won't cause a false reading, the pressure applied to one end of the capillary will register at the other even if it's got air in it. The air will just get compressed.

If it's got nothing but air it might be different, though

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Simon

The adventures of an owner builder in the Tallarook Ranges

1. The gauge is a capillary one, have tried two both the same reading.

2. New filter - It is a different one to the last time, I can test that like I did last time with the two gauges hocked up.

3.What oil are you running -HPR30, that is what I always run. Except for the run in of this motor it just had cheap oil in it. The engine had a maybe two hours in the 6deg temp it was last night to cool down and was still low. With my last motor always had 70-80PSI so this one is way lower then I’m use to.

4. The pick-up as far as I know doesn't have a hole and is fitting flush although the oil on the dip stick did have same little air bubbles, but they same times do from the gearbox?

5. What were all the bearing clearances, don’t know but they were all cheked by someone that did. Maybe wrong size bearing somewhere letting too much oil out of the pressurised system, all were 10/10 with the right bearings. I would suspect that if that was the case it would have never had pressure to begin with.

6. what does it look like is happening under the rocker cover, I will look at that today hadn’t throat of that

Small air bubbles I haven’t ruled this out as the dip stick had this and the line to the oil gauge had this at the start but seemed to setal once running for a bit.

Thanks Nathan, there has to be a simple answer to it.

Was the o-ring between the gearbox and engine in place and in good nick? You could be drawing air in through that join.

M

40psi is fine?

Not on my motors it's not and not when it gose down that fast.

Looks like we may have finally fixed it by putting a 1275 steel backed pump in it, tomorrow night will tell all. All the bench tests today say its looking good

Nathan.

i have 60 psi hot,and 70 psi idling hot,using a ball bearing and 40 mill rod,cheers the doc,i use hpr 30 also,did remember seeing a thread on dodgy oil pump shafts,this could be your problem,dont, know your engines history,could it be a possible spun bearing???.hope this aint the case,20psi is low,and in my experiance there is almost always a mechanical reason for this.cheers andy

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First you get the money,then you get the power,then you get the Mini.

if you did drop oil pressure for any reason the bearing might not last long.

what type of bearings did you use for this build?