Markus Posted March 11, 2019 Report Share Posted March 11, 2019 Just had my engine rebuilt and a new oil pump and PRV fitted but when cranking over to build pressure before first start up I'm not getting any oil pressure. I even removed the PRV to check if oil is flowing but nothing. Can anyone shed any light on what I should do? Cheers! Quote Link to post Share on other sites
Mike C Posted March 11, 2019 Report Share Posted March 11, 2019 Did you pack it with Vaseline to provide an initial seal? Quote Link to post Share on other sites
Waldi Posted March 11, 2019 Report Share Posted March 11, 2019 Better ask the supplier as Mike recommends before damage is done. how long did you crank? It took some 30 seconds on my car after the rebuild before I saw pressure on the dash board. remove the plugs to lower the forces on the bearings. if you have a modern filter, you can fill that with oil. have you tested the pressure gage (with compressed air), so you can be sure it is indicating. If the pump is not self-priming, you can fill the oil gallery by pumping oil in, this will fill the pump too. Others may know the best point for this (the oil pressure gauge pipe is hard to get to and if you do it via the prv I’m not sure if it will reach the pump or drain back in sump. Waldi Quote Link to post Share on other sites
astontr6 Posted March 11, 2019 Report Share Posted March 11, 2019 1 hour ago, Waldi said: Better ask the supplier as Mike recommends before damage is done. how long did you crank? It took some 30 seconds on my car after the rebuild before I saw pressure on the dash board. remove the plugs to lower the forces on the bearings. if you have a modern filter, you can fill that with oil. have you tested the pressure gage (with compressed air), so you can be sure it is indicating. If the pump is not self-priming, you can fill the oil gallery by pumping oil in, this will fill the pump too. Others may know the best point for this (the oil pressure gauge pipe is hard to get to and if you do it via the prv I’m not sure if it will reach the pump or drain back in sump. Waldi I had this problem years ago after my car was laid up for 18 months. I was told to fil up the canister/cartridge filter with oil making sure that I had the type with a non return valve in it. Back fill the oil gallery with oil by taking out one of the blanking plugs. To my surprise it took quite a bit of oil before it over flowed. I use an oil syringe to do this. Oil pressure came back within 5 seconds to my surprise. Good luck! Bruce. Quote Link to post Share on other sites
SeanF Posted March 11, 2019 Report Share Posted March 11, 2019 9 hours ago, Markus said: Just had my engine rebuilt and a new oil pump and PRV fitted but when cranking over to build pressure before first start up I'm not getting any oil pressure. I even removed the PRV to check if oil is flowing but nothing. Can anyone shed any light on what I should do? Cheers! Hi Markus, This happened to me when I was trying to build pressure prior to my first start a few months ago. After some research I came across the advice to remove the oil pressure relief valve and using a squeegee bottle or a trigger oil can, pump about 100ml of oil into the opening. Make sure you get the nozzle all the way in so that the oil goes down inside to the pump. Replace the PRV nut and try again. Worked for me and it was such a relief to see the needle climb on the gauge! I was also advised that there could be an air lock in the small pipe to the back of the OP gauge so to remove the pipe from the gauge and pump some oil down the pipe also. I did both and between them they worked. I assume you have filled the filter with oil? Cheers, Sean Quote Link to post Share on other sites
Tim D. Posted March 11, 2019 Report Share Posted March 11, 2019 You can also manually prime the pump by taking the distributor off and then turning the oil pump with a tool that has a slot one end to engage with the top of the pump. You turn the tool with a drill (anticlockwise I think). You know when it begins to prime because the drill has to work harder. Tim Quote Link to post Share on other sites
Andy Moltu Posted March 11, 2019 Report Share Posted March 11, 2019 The easier way is to pull out the PRV and pour 250ml of oil in this way - drains pretty well straight to oil pump and usually enough to prime it. Put the PRV and spring back in and turn it over until pressure builds up. Occasionally it's because the oil pump drive hasn't engaged properly with the drive gear, but I'd prime it before taking off the dizzy etc. If you use Tim D's suggestion make sure you use a battery drill with a torque control so that you don't do any damage to the drive or yourself when pressure builds up and resistance increases. Quote Link to post Share on other sites
John L Posted March 11, 2019 Report Share Posted March 11, 2019 If its the new aluminium pump with the round mesh on the suction pipe, I think you have to readjust it to the correct length as in the WSM. or it will be too high up the oil level in the sump. Not sure why they always come screwed in, perhaps to save on packaging? John Quote Link to post Share on other sites
colin3511 Posted March 11, 2019 Report Share Posted March 11, 2019 Exactly at this stage too. Initially turned it over with plugs in. No pressure after several seconds. Removed the plugs and the high torque starter motor span over much, much faster. Within 5 seconds the oil pressure was 100 psi, even with a bad leak from the oil filter seal at the block interface. I used the original oil pump as the 3 new ones I checked had much larger clearances, which would result in reduced displacement and therefore pressure. Colin Quote Link to post Share on other sites
Waldi Posted March 11, 2019 Report Share Posted March 11, 2019 100 psi is probably why the seals are leaking. I have K&N oil filter, and with 70-80 psi it is wheeping, although tight. Waldi Quote Link to post Share on other sites
colin3511 Posted March 11, 2019 Report Share Posted March 11, 2019 Hi Waldi, Poor installation on my part. The seal will take significantly more pressure than 100 psi. Never had a problem before on previous cars with 100 psi pressure. Cold oil so the PRV would restrict flow out to sump, allowing the high pressure to be seen (delta P). Colin Quote Link to post Share on other sites
cookie Posted March 11, 2019 Report Share Posted March 11, 2019 2 hours ago, Tim D. said: You can also manually prime the pump by taking the distributor off and then turning the oil pump with a tool that has a slot one end to engage with the top of the pump. You turn the tool with a drill (anticlockwise I think). You know when it begins to prime because the drill has to work harder. Tim We did the same as Tim, struggled to get pressure after a full rebuild but using the drill worked well, sorry can't remember which way the drill should spin. Good luck Dave Quote Link to post Share on other sites
Markus Posted March 11, 2019 Author Report Share Posted March 11, 2019 Thanks guys. When I first noticed the gauge wasn't moving I removed the pipe as I thought it may have been air locked but that didn't help. Then removed the PRV and cranked but no oil flowed out of the hole so poured oil into the PRV port and tried again but no oil flowing out. By this stage I'd been cranking for approximately 5 minutes in total so I'm getting a little worried about the time it's been without pressure. Might try making up a shaft and hitting it with the drill. Mechanic who built the ending coming over tomorrow so hopefully all will be good. I just want to get it done so we can go driving! Thanks again! Quote Link to post Share on other sites
Gary Flinn Posted March 12, 2019 Report Share Posted March 12, 2019 Anticlockwise for the drill if you use that method. It does work, but takes a while to build up the pressure? Gary Quote Link to post Share on other sites
SeanF Posted March 12, 2019 Report Share Posted March 12, 2019 11 hours ago, Markus said: Then removed the PRV and cranked but no oil flowed out of the hole so poured oil into the PRV port and tried again but no oil flowing out. Markus, How much oil did you put into the PRV hole? When I did it I kept pumping it in until it started to flow back out the hole, then closed the PRV up again and cranked. Not sure you should leave the PRV open when cranking as pressure will not build up and nothing will flow. Cheers Quote Link to post Share on other sites
Waldi Posted March 12, 2019 Report Share Posted March 12, 2019 If the pump is filled with oil and the suction sieve is submerged in oil and cannot draw air in, the pump will (should) deliver oil. No back-pressure is needed. Waldi Quote Link to post Share on other sites
colin3511 Posted March 12, 2019 Report Share Posted March 12, 2019 Waldi is correct. The pump will deliver oil at displacement x rpm. The pressure is generated by the resistance in the system. With the prv removed you should see most of the oil there as this is the easiest route for the oil to travel. This is assuming the oil pump is OK. If the clearances are excessive, this will reduce flow rate proportionally to tolerances. Colin Quote Link to post Share on other sites
SeanF Posted March 12, 2019 Report Share Posted March 12, 2019 Thanks guys. Oh well. Shows how much I know Quote Link to post Share on other sites
Markus Posted March 13, 2019 Author Report Share Posted March 13, 2019 We have pressure! Yay! My mechanic came to visit with a cordless drill and a pump drive shaft and after a couple of false starts I had a lovely, and I do mean LOVELY, oil spill on the concrete garage floor. He had that drill turning counter-clockwise for quite a while with the PRV removed but once we put the PRV back in place we had a gusher. Everything back in place and we had ignition and lots of wonderful noise. Still lots to do before getting back on the road but we're well on our way. Thanks again to everyone for all the support and ideas. Quote Link to post Share on other sites
cookie Posted March 13, 2019 Report Share Posted March 13, 2019 Excellent, good luck with getting it back on the road. Dave Quote Link to post Share on other sites
SeanF Posted March 13, 2019 Report Share Posted March 13, 2019 Great news Markus Quote Link to post Share on other sites
Waldi Posted March 13, 2019 Report Share Posted March 13, 2019 Very good Markus, another tick in the box:) Waldi Quote Link to post Share on other sites
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