Sierra Posted June 8, 2017 Report Share Posted June 8, 2017 How possible it is to have a faulty oil pump? What are some of the symptoms of having a bad oil pump? I'm working on A14 engine that was rebuilt from previous owner. Thanks in advance Quote Link to comment
racerx Posted June 8, 2017 Report Share Posted June 8, 2017 No or low oil pressure, since its bad, valvetrain can be noisy than normal. Temp.,can rise. But maybe ur sending unit is not read in right. Quote Link to comment
Sierra Posted June 9, 2017 Author Report Share Posted June 9, 2017 Thanks for the response racerx, I definitely have a very noisy valve-train and the oil presume light is on even after I replaced the sensor. It also has low power. I checked compression on all four pistons and all average 90 psi. Quote Link to comment
racerx Posted June 9, 2017 Report Share Posted June 9, 2017 Oil pressure is low. Have u adjusted your valves? Quote Link to comment
racerx Posted June 9, 2017 Report Share Posted June 9, 2017 Meant your compression is low. Quote Link to comment
Sierra Posted June 9, 2017 Author Report Share Posted June 9, 2017 I was just looking at my service manual so I can get the right pressure numbers. So the ideal pressure should be between 170 and 190 PSI, based on that, I am way low. I also realized that I did the compression test with the throttle valve close. I adjusted the valves cold at .25mm I will post an updated tomorrow when I redo the compression test correctly. Thanks again for your feedback. Quote Link to comment
racerx Posted June 9, 2017 Report Share Posted June 9, 2017 Engine should also be warm when doing test and use screw in type of compression tester. Btw how many miles on engine? Quote Link to comment
banzai510(hainz) Posted June 9, 2017 Report Share Posted June 9, 2017 try a different oil filter Quote Link to comment
Doctor510 Posted June 9, 2017 Report Share Posted June 9, 2017 Hook up a mechanical gauge Quote Link to comment
racerx Posted June 9, 2017 Report Share Posted June 9, 2017 /\...yep, went with route eventually. Quote Link to comment
Sierra Posted June 9, 2017 Author Report Share Posted June 9, 2017 I will pick up a new oil filter today. How do I install a mechanical gauge on an A series engine? Quote Link to comment
racerx Posted June 9, 2017 Report Share Posted June 9, 2017 U didn't answer miles on engine....also when u buy the mechanical gauge, it should have directions...u may want to consider, getting a cluster of water, voltage and oil pressure gauges. Quote Link to comment
Sierra Posted June 10, 2017 Author Report Share Posted June 10, 2017 This is not what I wanted to see. Now, I need to replace my camshaft and oil pump. Quote Link to comment
racerx Posted June 10, 2017 Report Share Posted June 10, 2017 Dang it....good luck with build. Quote Link to comment
racerx Posted June 10, 2017 Report Share Posted June 10, 2017 Do you think u did not have oil which caused this... Quote Link to comment
Doctor510 Posted June 10, 2017 Report Share Posted June 10, 2017 This is not what I wanted to see. Now, I need to replace my camshaft and oil pump. Sad, sorry to see that... Quote Link to comment
Crashtd420 Posted June 10, 2017 Report Share Posted June 10, 2017 Just my curiousity... anyone know what causes a failure like that?... Quote Link to comment
Stoffregen Motorsports Posted June 11, 2017 Report Share Posted June 11, 2017 Boy, who knows... Since this oil pump is driven by the cam, it's possible that the gear on the cam just wore out and chipped a tooth. Maybe the engine sat for a long time and rust formed on the gears. Maybe there was foreign debris in there somewhere. The lifters on these engines can chip on the edges, maybe that happened and a chip found its way to the gear and got jammed. One other possibility is that the oil pump froze (from lack of use or poor maintenance) and the gear couldn't take the beating. I doubt the cam is in good shape after that failure. 1 Quote Link to comment
racerx Posted June 11, 2017 Report Share Posted June 11, 2017 Or maybe there's tons of sludge and oil was not flowing Quote Link to comment
Sierra Posted June 12, 2017 Author Report Share Posted June 12, 2017 Sorry to keep all of you in suspense. So, this is the story. Got the engine, rebuilt already by a shop from previous owner. I got the oil pump from ebay. I was the one that installed the engine and placed all other essential parts in order to have a working power plant. This was my first time replacing an engine. After this mishap, I did some research and talk to some more experienced Datsun guys. Long story short. I did not bled the oil pump. I simply installed it and then install the filter. For some of you that do not know (like me) you need to bleed the pump in order to get the oil pump gears lubricated. Since I failed to do so the gears simply got to hot to quick and ceased to move. Causing the damage you see in the picture. Very expensive learning lesson for me. Now, I am opening the engine so I can inspect the damage. since I run the engine 3 or 4 times for about 5 to 10 minutes each time. And that's what happen. Quote Link to comment
racerx Posted June 12, 2017 Report Share Posted June 12, 2017 K, thanks for clarifying what happened. I figured oil was not getting there. Quote Link to comment
datzenmike Posted June 13, 2017 Report Share Posted June 13, 2017 I doubt this. You should be able to start this dry and have oil in seconds. Probably a shitty eBay pump cheaply made in China. This is the real lesson learned here. Buy quality made in Japan pumps if replacing them. If buying Chinese, only get floor mats... no one cares if they break. Quote Link to comment
Doctor510 Posted June 14, 2017 Report Share Posted June 14, 2017 Sorry to keep all of you in suspense. So, this is the story. Got the engine, rebuilt already by a shop from previous owner. I got the oil pump from ebay. I was the one that installed the engine and placed all other essential parts in order to have a working power plant. This was my first time replacing an engine. After this mishap, I did some research and talk to some more experienced Datsun guys. Long story short. I did not bled the oil pump. I simply installed it and then install the filter. For some of you that do not know (like me) you need to bleed the pump in order to get the oil pump gears lubricated. Since I failed to do so the gears simply got to hot to quick and ceased to move. Causing the damage you see in the picture. Very expensive learning lesson for me. Now, I am opening the engine so I can inspect the damage. since I run the engine 3 or 4 times for about 5 to 10 minutes each time. And that's what happen. Truly you mean PRIME the pump, not bleed! 1 Quote Link to comment
Sierra Posted June 14, 2017 Author Report Share Posted June 14, 2017 Correct! Prime the pump. Quote Link to comment
Stoffregen Motorsports Posted June 14, 2017 Report Share Posted June 14, 2017 I doubt this. You should be able to start this dry and have oil in seconds. Probably a shitty eBay pump cheaply made in China. This is the real lesson learned here. Buy quality made in Japan pumps if replacing them. If buying Chinese, only get floor mats... no one cares if they break. Agreed. Engines sit for long periods and the oil drains out. They are self priming pumps. Take the pump apart and look at the gears. Are they scored on the end (flat) surfaces? Is the housing scored anywhere? I bet the pump was built too tight to begin with and bound up. Quote Link to comment
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