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MG Midget and Sprite Technical - No oil Pressure

No oil pressure after engine rebuild by specialist.
After refitting this engine I found on turning over with no ignition I had no oil pressure. Finding aritcles on forums I removed the oil cooler pipe from where the banjo is fitted and fitted a funnel with oil as suggested turning engine anti clockwise. I did this numerous times including leaving oil to drain into the engine. On cranking with plugs removed after a couple of times I got oil pressure about 50psi. Leaving overnight next day no pressure. removed filter full of oil I have also replace oil pressure relief valve still no pressure.From the banjo joint which way does the oil flow as I can't find this anywhere, to the oil cooler then back to the filter?
Any ideas?
Peter King

Yes, the oil comes out of the block behind the distributor, to the cooler, then back to the filter.

I would normally do what you have done, i.e. pouring oil into the outlet and turning the engine backwards to prime the pump, spin it up with the plugs out until pressure is achieved, then fire it up.

I don’t know why you would lose pressure again.

Was the filter filled with oil before it was fitted?

Are the oil cooler and pipework the same as before, or are they new? If the latter, it might be an idea to also pour some oil down the hose to fill the cooler.

If you spin it over again to build pressure, put the plugs in and start it up straight away.
Dave O'Neill 2

Have you bled the oil pressure gauge pipe? After my last rebuild it took me a hell of a time to prime the system, even with reverse priming. I also have a cooler, and it does seem to make priming more difficult. Silly question, but presumably you filled up the priming port on the n/s of the block?
Les Rose

Had this once upon a time 40 years back. The phone had interrupted me when doing up the oil pick-up pipe into the block. It was not quite fully home but looked it. Brain distracted by the phone conversation (another customer waving money at me) and I moved on to the next task in reassembly.
Fortunately like you I prefer to get pressure up before start-up and found the problem before any harm done.
Lesson learned, I never interrupted a tightening sequence again.
Paul Walbran

A trick I used to prime the oil pump in the EXPAG engine in my MG TF was to block up any breather holes in the engine and then give a blast of compressed air down the dip stick tube. May not be of use to Peter but others may use it some day.


Jan T
J Targosz

Missing oil pump drive-pin in back of camshaft perhaps?
Not all camshafts have this and not easy to check obviously
Simon Wood

Since you paid a 'specialist' to do the rebuild, as much as you want to fix it yourself, and fix it quick, you should really get them to fix it.

Otherwise, you may inadvertently give them an excuse to blame you if something is actually wrong.

It could be a number of things, and unless/since the simple checks you've done already don't/haven't fixed it or ID'd the problem, then it's sump off, engine out, pump off, caps off etc.

Ay this stage, my advice is give the engine builder a call to protect yourself, and save yourself hassle.


anamnesis

Agree with Anam.
I had mine rebuilt by a specialist, Welsh Mg, a few years ago and had no problems with oil pressure when the engine was first started so I'd get in touch with your engine builder and ask what is going on.
Jeremy MkIII

This thread was discussed between 20/04/2024 and 22/04/2024

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