no oil pressure
no oil pressure
My Z20 had 60 lbs oil pressure when it was shut off. When it was started the next time it had none. Found broken oil pump and replaced it. Still no oil pressure. Checked oil guage outlet on block and no oil coming out. No oil coming out of cam. Pulled pump and is pumping when you spin it by hand. Changed to another oil pump. Checked the oil pressure relief. Still no pressure. Dropped the pan and checked oil pickup and it is clear. Have run out of ideas. Anyone got any? Any help would be appreciated.
Re: no oil pressure
Did you prime the oil pump before install? very important.
Re: no oil pressure
i didn't prime my pump when i built my motor and after running it for the first time it didn't take long until the pressure got up to 60.defdes wrote:Did you prime the oil pump before install? very important.
Re: no oil pressure
Wear can happen between "start up" and "didn't take long...". I am just saying, it's standard rebuild procedure.
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datzenmike
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Re: no oil pressure
Check the drive spindle. Assume the engine runs so the drive gear is likely OK but the end that drives the pump may be damaged. What was wrong with the broken one???
"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs
Re: no oil pressure
Appears that there was no oil pressure at next start and the OP found oil pump failure.
How did the oil pump fail? If there were parts that broke inside (rare, haven't heard about that before) then you might have a blocked passageway now. Bit of gasket or goo (more likely, which is why goo's a no-no) could also cause a blockage.
The first step is as has been mentioned, prime the pump. I used a long standard screw driver shaft with the handle cut off. Insert the shaft into a drill and spin until you build pressure.
If the replacement oil pump spins and pumps, it should be doing the same inside the engine. If you prime the pump and never get oil out of the top of the engine, you might have to start looking at blockages.
How did the oil pump fail? If there were parts that broke inside (rare, haven't heard about that before) then you might have a blocked passageway now. Bit of gasket or goo (more likely, which is why goo's a no-no) could also cause a blockage.
The first step is as has been mentioned, prime the pump. I used a long standard screw driver shaft with the handle cut off. Insert the shaft into a drill and spin until you build pressure.
If the replacement oil pump spins and pumps, it should be doing the same inside the engine. If you prime the pump and never get oil out of the top of the engine, you might have to start looking at blockages.
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson
Re: no oil pressure
The small drive tab that is in top of oil pump broke off. When we took the pump apart the rest of it seemed fine. No spare bits floating around. By the way the pump was gasketed. The oil pump/distributor shaft is fine and when motor is turned over the rotor turns so gears on shaft must be okay. We also put the shaft in a drill press to make sure it was straight and it was fine.
Yes, I'm stupid and didn't think to put oil in pump before assembly but there was oil in the replacement pumps that we changed out. I did put oil in new oil filter but not pump. I guess some blockage is the best answer and now I have to figure out how to find that. Anyone have any briliant ideas? I guess I could try to use air to blow out some areas but I don't want to lodge a blockage tighter.
Yes, I'm stupid and didn't think to put oil in pump before assembly but there was oil in the replacement pumps that we changed out. I did put oil in new oil filter but not pump. I guess some blockage is the best answer and now I have to figure out how to find that. Anyone have any briliant ideas? I guess I could try to use air to blow out some areas but I don't want to lodge a blockage tighter.
Re: no oil pressure
Pull the shaft to the distributor, pull the distributor, install the oil pump and prime using the screwdriver shaft trick. If you can pull oil into the pump, then you know your blockage isn't between the oil pan and the pump. If you verify oil in the pump but never get oil into the block (via leakage through the oil pressure sender boss) or into the head (leakage through the cam) then you can break down the oil circulation problem by sections.litho9000 wrote:I guess some blockage is the best answer and now I have to figure out how to find that. Anyone have any briliant ideas? I guess I could try to use air to blow out some areas but I don't want to lodge a blockage tighter.
I'd still attempt to prime the pump first. Just because there's oil in the pump when you installed it doesn't mean it's going to hold the prime while the pump sucks the air in the pick up tube.
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson
Re: no oil pressure
Did you put oil back in the motor?? I know what you're thinking....stupid question,.....but you would be surprised.... 
Re: no oil pressure
Yes there is oil in the motor. I'll try the screwdriver trick. A friend also suggested using an oil can to pump oil into the oil pressure outlet to see if it comes out at the pump. I try and find a long enough screwdriver tomorrow and try that. Thanks
Re: no oil pressure
Thanks okayfine. Instead of using a screwdriver I used a piece of rolled rod and filed it to fit in the oil pump drive slot. I hooked it up to the pump and drill. After much sputtering I have oil. I guess it was an airlock. Thanks again for everyone's help.