22 replies to this topic

[mini-mad-mark]

My experience from years ago of fitting the oil pump gasket back to front (as you've done) on a new engine resulted in zero oil pressure. As a result, I now always fit the gasket to the block then fit the pump, rather than fit the gasket to the pump first.

Wasn't me, was the engine builder, I just bolted the head onto the block and that onto the box and transfer case but answers my question I think

Edited by mini-mad-mark, 17 January 2025 - 09:19 PM.

[mini-mad-mark]

Arghhh!!!

 

Got everything cleaned up, gallery plugs removed before having the block washed, had crank polished (its been previously balanced and cross drilled, the engine shop doing the work inspected it and pronounced it good)

 

I then re-assembled with new bearings and oil pump (gasket correct way round!) and new oil gallery plugs with a smear of RTV sealant aaaaannnnnddd.......

 

 

Oil gallery plug still leaks at the front and still intermittent oil pressure  -        and other such emotions.

 

 

The first time I spun the engine without plugs to test for oil pressure and leaks I got 45psi reasonably quickly (30 seconds) and didn't see the leak immediately, but then the second time it took absolutely ages to get to 40psi (more than a minute) when I thought it should be more instant once I had oil pressure the first time, and then I found the leak again so I threw down the spanners in a fit of pique and have no real idea where to go now

 

 

So has anyone got any surefire tips for:

 

1) fixing the oil gallery plug leak  - would tapping and fitting a threaded plug be a more certain seal? 

 

2) what could cause intermittent reaching of oil pressure  - I had a centre oil pick up pipe fitted to the gearbox (before the first time I had the problem not since this time) could that cause any problem?

[mini-mad-mark]

I had a hip replacement 10 weeks ago and for a few months before that I was not in a good way with the pain and inability to move/get into positions to work on any of the minis, however I've now been given the "all clear" by the specialist  and physio so back onto the minis and in particular this engine.

 

Fixed the leak!!! - Tapped the hole M14 and found some M14 plugs on Ebay from China (nothing found in the UK) but they turned up within 9 days so not too bad I thought.

 

However......I still have the intermittent oil pressure issue.

 

Spun the engine on the starter and first time got nothing, churning it for about 90 seconds,  second time after about 45 seconds I got 70 PSI on a Smiths capillary gauge (previous reading were a cheapo electric gauge) but then after letting it settle back to zero I got nothing, churning it over until the starter was too hot to touch at which point I gave up. I would expect it to go back up fairly quickly if not instantly once I got oil pressure the first time?

 

Any thoughts for intermittent oil pressure please as I'm out of ideas.

 

My thinking is that the system must be somewhat OK to get 70PSI on the starter but can't understand why it doesn't reach that:

a) more quickly 

b) each time I spin the engine

[Earwax]

Hi  MM Mark.  I hope your hip replacement results in better sleeping nights, after you solve this conundrum of the oil pressure.

 

Your spinning the engine up experience is baffling, as you said normally once Primed and up it is relatively easy to replicate the pressure on second go.

 

I have no real answers for you - but some guesses that don't involve pulling things to far apart. ( mull them over )

 

1. Can the grub screw ( or threaded plug) oil galley replacement go into far....

 

2. I would replace the oil filter and use the oil transfer pipe to backwards fill the filter and system prior to spinning- checking gaskets/ seals as well

 

3. The oil pressure release shuttle or ball - wondering if scored and effecting flow ( was okay but now stuck?)

 

4. With rocker cover off ( and ideally a helper to turn ignition or you using a remote starter button) see if oil is moving - or if nothing happening up top then crack a lower join in the oilway to see if pulsing ( mess will ensue)

 

beyond those - sadly my thoughts go to more invasive checks or replacements.

- oil pump sitting proud or something wrong internally - O ring between block and gearbox - and silcone blocking pick up or vertical galley etc

- swarf in a galley

[mini-mad-mark]

Hi Earwax, yes I was having real problems sleeping before the operation (pain of the hip not the pain of this engine although it has been playing on my mind !!)  

 

To try and answer your points:

 

1. Can the grub screw ( or threaded plug) oil galley replacement go into far....

I was very careful not to turn the thread too far into the gallery  - stopping short of the oilway down from there - and made the plug only just long enough (9.5 mm and the oilway is 10mm from the end of the block) 

 

2. I would replace the oil filter and use the oil transfer pipe to backwards fill the filter and system prior to spinning- checking gaskets/ seals as well

Done this both times and also back filled the PRV with no success

 

3. The oil pressure release shuttle or ball - wondering if scored and effecting flow ( was okay but now stuck?)

Slight wear marks on the shuttle but definitely no raised metal that could cause it to stick and the seat seems OK so it shouldn't be allowing any flow when it should be closed

 

 

4. With rocker cover off ( and ideally a helper to turn ignition or you using a remote starter button) see if oil is moving - or if nothing happening up top then crack a lower join in the oilway to see if pulsing ( mess will ensue)

I haven't tried this but prepared to try anything now as I've exhausted my limited knowledge so I'll give it a go before I go too much further

 

 

beyond those - sadly my thoughts go to more invasive checks or replacements.

- oil pump sitting proud or something wrong internally - O ring between block and gearbox - and silcone blocking pick up or vertical galley etc

- swarf in a galley

 

New oil pump and I checked that the screws didn't bottom out before clamping the pump (and I put the gasket on the correct way round unlike the first time by the engine builder)

O ring definitely in place

The block has been properly cleaned (plugs out) twice so should be well clean 

 

 

Previously I mentioned the centre oil pick up pipe I had fitted - I have heard of bad pipes that can cause pick up issues but I looked at the pipe the last time the engine was apart and it seemed to be flush to the mounting plate but maybe I need to take this off and check

 

 

Thanks for the feed back, I think I probably need professional help (but it WAS put together by an engine builder the first time and it didn't work so might not be a guarantee of success)

[imack]

The pick up pipe is a distinct possible cause of you oil pressure issue. As you're already aware, there can be an issue withe the mating face of the flange being distorted or uneven and not sealing squarely with the gearbox case.
Recently, on MK1 forum was this pipe which was being hit by the con rod big end (1098), in this case the pipe fractured causing total loss of oil pressure, but if it just created a pin hole it might cause the symptoms you're experiencing.
Also, potentially a pin hole in the weld or braze where the pickup pipe is joined to the flange.

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Edited by imack, 25 August 2025 - 07:02 AM.

[Shooter63]

The COP's being sold are bang average at best, things to check
1 Is the mounting flange flat, check this by running a smooth file across it and look for low/high spots
2 Bolt the flange to the gearbox, is the COP hitting the gearbox web, is the support bracket lining up with the bolt hole
3 Select reverse to see if the COP is hitting the reverse gear

I had all these problems, I filed the flange flat, relieved the gearbox web and tweaked the pick up end to clear the gear. Also check the COP for weld pin holes

Shooter

[mini-mad-mark]

Sorry for the delay in responding, I've had no luck getting on for the last few days.

 

Getting the engine back to pieces this weekend hopefully and will look at the COP as I cant think of anything else that should cause a problem and I do get (good) oil pressure sometimes just takes a long time and is random as to whether it happens

 

Just to clarify my understanding 

 

1 Is the mounting flange flat, check this by running a smooth file across it and look for low/high spots

Understand this clearly and can check/fix - however does the gasket allow for a small degree of imperfection

2 Bolt the flange to the gearbox, is the COP hitting the gearbox web, is the support bracket lining up with the bolt hole

Do these issues stop the flange from mating squarely to the box leading to a gap?

3 Select reverse to see if the COP is hitting the reverse gear

Does this cause the pipe to be forced off the flange - not directly a problem ATM as I haven't selected reverse during the cranking  but I will check whilst I'm in there

 

Is there a way I check the weld for pin holes other than visually?

 

 

 

Thanks for the input