17 replies to this topic

[spritey]

My 1275 carb engine has low oil pressure on idle , any ideas what could possibly solve the issue I've changed filter and oil is there any pipe work or anything I can change before it's an engine out rebuild

[spritey]

My 1275 carb engine has low oil pressure on idle , any ideas what could possibly solve the issue I've changed filter and oil is there any pipe work or anything I can change before i go to a rebuild . When it's driving and I'm up the revs it's fine it's on idle and very low revs it goes to around 20

[dklawson]

Define "low".

 

You need a minimum of 10 PSI at hot idle, 20+ is better.  For each 1000 RPM off idle you want an additional 10 PSI up to the set point at which the relief valve opens.

 

Low oil pressure at idle can be from a worn pump, a new pump with excessive clearances, worn bearing, and perhaps a relief valve that is jammed open.  The only one of those you can look at and address with the engine in the car is the relief valve condition.

 

Also, the grade of oil you use will affect the pressure.  While later engines may call for thinner oils, 20W50 is what the early A-series used to maintain proper oil pressure.

[petey81]

Thats fine search on this forum for the answers

[spritey]

My 1275 carb engine has low oil pressure on idle , any ideas what could possibly solve the issue I've changed filter and oil is there any pipe work or anything I can change before i go to a rebuild . When it's driving and I'm up the revs it's fine it's on idle and very low revs it goes to around 20

[sonikk4]

Why do you keep posting this question. You have already started two other threads for the same question which i have merged.

[dklawson]

And now I have merged these two.  Please, no more new posts on the same topic.

[spritey]

My phone kept coming up with error so it must have went a bit strange , the other post was about an spi so I didn't know if it was different , the orange light comes on when started and goes off after a few seconds , the oil pressure gauge then rises to 50-60 then once hot it drops to the red on the gauge at idle , how do I check the relief valve is it a simple replace if I bought one or if there a special setting

[dklawson]

I cannot answer any questions about injected Minis.  If the SPI and MPI kept the relief valve in the same place as other A and A+ engines, it will be on the front of the block just to the left and slightly above the distributor as you stand looking at the engine.  The valve is held in place by a spring under a domed nut.  You remove the domed nut, sealing washer, spring, and finally the plunger that is the working part of the relief valve.  If it is stuck you can thread a tap into the back of the plunger just enough to extract it.  All parts are available from most parts suppliers.

 

Be advised though that if the relief valve is not stuck, no amount of fidling with it will change your hot idle oil pressure.  The valve does not control low pressure, only the maximum pressure that will reach the engine.

[spritey]

Thanks dklawson , so to put it back together it's just tighten am I right in thinking there's no certain turns for setting

[gazza82]

Just tighten it. The nut doesn't adjust anything.

[spritey]

Thank you u , I will have a look tomorrow

[spritey]

Here's a couple pics can you tell if it's ok

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[spritey]

Here is readings for a little bit revs

I haven't had chance to check the relief valve I plan to check that tomorrow

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•  image.jpg   72.35K   11 downloads

[Cooperman]

That all looks fine.

Presumably you are using a top quality 20w50 mineral oil and change it every 2000 to 3000 miles together with the filter.