Oh no !!

I was due to take the car to an airfield today to shake down the gearbox.

Started it up to take it out of the garage and no oil pressure......not even a twitch on the gauge

EEKKK I thought and quickly switched it off. rechecked the levels and pipes, no leaks etc, remembered the engine hasn’t run since Snetterton so perhaps it just needed a bit of time for the oil to get round the engine.

Tentatively I restarted....1sec...2..sec......10 seconds no pressure and looking through the rocker cover cap its looking awfully dry none of the usual oil flinging off the cams.....15 seconds  SWITCH IT OF!!

Swor...allot.... phoned the airfield cancelled the booking...pushed the car back into the garage....fetched tools!

Phoned Ernie, he suggested I check the oil pump pressure regulator and the oil filter. So I removed checked and cleaned the pressure regulator, and fitted a new oil filter.

Now this could be a clue. I then cranked the engine for 10 seconds, and removed the new oil filter, not a drop of oil in it. I would have expected it to fill with oil.

Moving on, I have now also checked

Oil pressure lamp and gauge wiring - ok

Oil pressure sender unit checked with a foot pump and tube attached - ok

Sump removed and oil pickup tube checked - It’s still securely mounted. I haven’t checked for blockages yet but the mesh looks clear in fact the inside of the sump was very clean with no sludge. And no metal bits on the sump plug

I am pretty stumped now. I would expect if it was a big end bearing or something like that there would still be some oil pressure all be it quite low. And lots of bits of bearing in the sump.

It’s difficult to imagine how the oil pump could fail as its driven straight off the crank but I guess it could happen

I can’t imagine how a cylinder head gasket failure would cause total pressure loss especially without lots of oil usage, either into the water or cylinders.

And what’s really weird is it was fine when I parked it up! 

My next plan is to take the oil pump off and have a close look at that maybe its seized.

Does anybody have any suggestions as to what else it could be or what else I could check? I’m going back to my cold garage floor!

Steve

Hi Steve,

Several possible causes spring to mind, however you have covered most of the obvious ones.

Remember that the oil system works on both vacuum and pressure.  The oil pump has to lift oil from the sump.  Check for a cracked oil pickup pipe or failed gasket.  Also, I cannot remember but I think that the gallery in the block may have a plug that could have fallen out or failed.  Also, take off the pump and check that the woodruff key is ok and it is still able to turn the pump. Fill the pump with oil, and check that it does actually pump by turning it with your fingers.  I wouldnt expect a failed pressure relief valve to cause total pressure loss, but I suppose it is possible.  Check that the valve, spring and seat are all ok.  As the pump isnt pumping any oil at all, I suspect the fault to be caused by the pump not getting any oil in the first place than loosing it under pressure.

Let me know how you get on,

Regards

Martin

Thanks Martin

I Havent managed to get the pump off yet, the bolt in the middle of the pulley is very tight! but Ive ordered a longer breaker bar that should help with that job.

I have removed the oil pickup pipe to give it a closer inspection on the workbench, the pipe seems fine. Unfortuanatly as I turned it around lots of pieces of shrapnel fell out of the pickup end. Biggest is about 1cm square the rest are smaller, they have a curved surface so i suspect are bits of bottom end bearings. There are nowhere near enough pieces to make up a whole shell, but the rest could have gone anywhere I suppose.

I dont know if these are from a previous failure or a result / cause of the lack of oil pressure. Either way it looks like the only thing for it is a bottom end rebuild.

I dont have the tools or the measuring equipment to carry this out to a high standard. I could probably put it together with new bearings etc but...not sure how long it would last!! 

Can anybody recommend an engine builder? locations not really important as nowheres too far from the midlands!

Cheers

Steve   

Quick update

Finally got the bottom end apart. pump was ok ish, a little scored on the back plate but thats all.

However main bearing on cylinder No4 was seized and worst still the crank is cracked! so if anybody has a good crank they would like to swap for some beer tokens im interested!

However this still dosent solve the mystery of why the pump couldnt even fill the oil filter, unless the seized bearing had blocked the oil way? I hate not being able to figure this out!! anyway the engine is at harvey engineering being completey rebuilt......so thats 1 race one new gearbox and a rebuilt engine........its expensive this motorsport init!!!

SB

Hi Steve

I've sent you a PM on this.

All the best

Alec