No or very little oil pressure
Turbo Mini Forums

If something is worth doing, it's worth doing half of.

plastiguage ordered; will strip it at the weekend and see what I find

you could just bung some lorry 20/50 in ,and see how that affects it , also , your pressures cold and slightly warm seem ok , maybe a oil cooler ?(if there is not one on there already .)

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Tried a totally new plunger, and spring? Also made sure its nice and flush against the seat

Edited by minimole23 on 2nd Jul, 2015.

Have you checked the oil pump bolt lengths? They need to be measured when a pump is changed as pump depths aren't consistent. The bolts feel tight and torque up, but can still allow the pump to float by a few thou.

Robert, no oil cooler fitted. Did wonder sbout trying another oil but with the slow pressure build up from initial start, i think there is something else going on

Mole, have tried various springs and plungers

Graeme, not checked that.


Anyway, with the delay on pressure at cold start and the weak synchro, i no option but to pull it and see. Think i'm going to remove the oil jets as well

fair enough rob , at last that will give most peace of mind . and you can have a good measure up of things too.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

I had similar issues with zetec jets. The check valves in them I removed, and the engine always took time to build pressure from first start and tickling the oil light on hot idle.

In my opinion, I would be looking at those jets

thanks Colin. I've no idea on their flow rates although I did have the Zetec jets fitted before (albeit without the slow pressure build at cold).

I'd love to do one thing at a time to actually identify the culprit but a little worried I'd change more than a few things in one hit and never actually identify what was causing it..........

suppose I could check the pump and pull out the jets and try again

Why fit oil jets unless you have a windage tray?

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

I'm running standard pistons; was just trying to give it a bit more protection but starting to wonder myself. The car is never going to be big power as I've got the metro for that so thinking I don't need them

given the photo of the oil pump gasket above, also wondering if the pump isn't fitted correctly (bolts as noted by a few too long) and allowing loss around that area/ tearing of the gasket

If something is worth doing, it's worth doing half of.

Interesting John. As I say, my concern is dealing with a few issues in one and not knowing which was the actual problem.

for now, I think i'll pull them and see.

I am of the opinion that standard metro turbo pistons are as good as Omega cast pistons.

Van had tons of abuse and pistons came out clean as a whistle without a mark on them.

If something is worth doing, it's worth doing half of.

My guess is that if there's any blockage before the relief or it jams shut when warm, the hydraulic pressure would rocket and tear the gasket back to the low pressure side, just as pictured.

Before you pull the engine is it worth detaching the pipe to the filter housing, put a gauge on the end, then cranking to see if it builds and holds pressure? Might give you more confidence as to whether it's the pump side, or bearing side. Sad times :(

Edited by PhilR on 3rd Jul, 2015.

I know what you mean but the synchro needs fixing anyway so I'm not really loosing out on pulling the engine other than quality time with the family, painting house, cutting grass etc!

Oil jets are easy enough to test with a foot pump. Mine open and hold at 30psi so shouldn't affect idle oil pressure. Would be a shame to take them out, just in case.

to be fair, I did test them at the time but cant remember what the pressure was; you do have a point..........

OK, looked at my notes and they opened at around 30psi. Now a quick search online found info suggesting they opened at 28psi so close enough. So that could rule out an impact on low pressure below 28psi anyway particularly at idle (on the assumption that they are operating correctly).

Eyes wide open I think as I proceed

How well are the oil jets sealed into the block?

Any internal leak will reduce idle oil pressure.

Also, bearing clearancies. Large clearance means more oil flow and again lower oil pressure at idle.

Oil pump lobe clearance. Large clearance and the pump is less efficient


Gasket is always a week point though. Can be indicated by the oil pressure taking a long time to build after the car has been left for a few days.

Jets are bolted in with a copper washer under so they should be good. Pump was new but I've never checked it for clearance.

Plastigauge turned up in post today so will being working on it over weekend

engine back out. found some more debris on the strainer again which wont be helping but doesn't explain the variable pressure between hot and cold.

However the pump gasket has torn again so I need to get the bottom of that. Joe has already suggested a couple of points that I'll need to investigate

I would say from that photo and the previous one, that the pump isn't seating on the gasket.
Although the bolts being too long is the most common/obvious cause it is also possible the drive dog on the end of the pump shaft is bottoming out in the slot on the end of the cam.
That I know is what Graham T found in his case.
Try inserting the pump without gasket or bolts and see if it rocks ever so slightly.
Or if it's a tight fit in the hole (so it won't rock even if it is bottoming out) bolt it in with plastigauge instead of the gasket and see what thickness it comes out.

Schrödinger's cat - so which one am I ???

I was having the same thoughts Rod, thanks. Going to skive off early today and pop up the workshop for an hour and investigate.