Posted June 19, 20159 yr comment_472278 Hi, i did change my engine lest fall. I had problems with my headone valve was not adjustable anymore so i bought that engine rebuiltfrom Datsunparts LLC think that was a mistake. The thing is burning oiland i got uneven oil pressure. It runs great pulls hard but burns oiland scarry uneven oil pressure. my other engine use to be dead center on theoil pressure gauge this one goes up and down. and i cannot figure the patern. It is not linked with reving it can be high at low rev and low at high rev and vice versa.complete aleatoire patern. Any body have an idea where to start. Thank`s Jean-P Link to comment https://www.classiczcars.com/forums/topic/51681-oil-pressure-uneven/ Share on other sites More sharing options...
June 19, 20159 yr comment_472284 The oil pressure sending unit by the passenger's side motor mount, to the right of the oil filter, could be bad. Clogged up or maybe just a loose wire connection. They are cheap too. Unplug the wire and clean the brass on the unit, then squeeze the wire connector so it will fit nice and tight. That's what I would do first. Edited June 19, 20159 yr by siteunseen Link to comment https://www.classiczcars.com/forums/topic/51681-oil-pressure-uneven/#findComment-472284 Share on other sites More sharing options...
June 19, 20159 yr comment_472286 my other engine use to be dead center on theoil pressure gauge this one goes up and down. If your oil pressure was dead steady with your old engine, it had the problem. Oil pressure should vary with the temperature of the oil and RPMs. When the engine is not warmed up, the oil pump must generate more pressure to circulate the thick oil. As engine RPMs increase more oil is pumped and will increase the output pressure. As the engine warms, it gets thinner and easier to push through the engine and thus less pressure is generated. The next question is whether you are burning oil or leaking it. Does the exhaust blow blue smoke? All the time or only after sitting at a stop light? How many miles have you put on the engine since the re-build? Some piston rings take a while to seat and seal properly. And finally, how much oil is being lost? How many miles do you drive before you are down a liter of oil? Link to comment https://www.classiczcars.com/forums/topic/51681-oil-pressure-uneven/#findComment-472286 Share on other sites More sharing options...
June 19, 20159 yr comment_472288 Another question, did you reuse your old oil sender or did the new engine come with one? Link to comment https://www.classiczcars.com/forums/topic/51681-oil-pressure-uneven/#findComment-472288 Share on other sites More sharing options...
June 19, 20159 yr Author comment_472290 Thank`s for fast answers I burned a liter in 250miles, there is 750miles since rebuild and i did change oil at 400miles and there was no grind in it. I have blue smoke when i leave a red light if i push-it. If i go smootly as soon as i will push it. have blue smoke almost every time i push it after idling or just smooth riding. I do not push it near red line yet but this engine and the one before realy like tobe pushed. My diagnostic would be valve seals but i cannot beleive that they were not changed. every pieces in there looks new. Link to comment https://www.classiczcars.com/forums/topic/51681-oil-pressure-uneven/#findComment-472290 Share on other sites More sharing options...
June 19, 20159 yr Author comment_472293 Ho just remember in the breakin starting procedure sent with the motorthere was adjust valve and the number given there were warm numbersAnd i did not check my Datsun manual i took these for cash i did adjust all valve to these numbers was suprised that they were all to tight.I ran the engine for 200 miles like this and i recheked my valves i took the number in my Datsun manual.they were all wrong to loose. But did not pass much time so i found the document shipped with the engine gavehot numbers for valves but say adjust before start. duuhh. anyway now they are OK adjusted but i did ran the enginewith loose valves for about 200 miles Link to comment https://www.classiczcars.com/forums/topic/51681-oil-pressure-uneven/#findComment-472293 Share on other sites More sharing options...
June 19, 20159 yr Author comment_472294 I did reuse my old sending unit. I will order a new one i think. Link to comment https://www.classiczcars.com/forums/topic/51681-oil-pressure-uneven/#findComment-472294 Share on other sites More sharing options...
June 19, 20159 yr Author comment_472295 I dont think it`s leaking oil because my garage floor is not covered with oil and the engine is completely clean 1 liter of oilwould have leave traces if it was leaking i think. Link to comment https://www.classiczcars.com/forums/topic/51681-oil-pressure-uneven/#findComment-472295 Share on other sites More sharing options...
June 19, 20159 yr comment_472300 This won't make you feel better or help your problem directly, but it might help you if you find problems. Better check your wipe patterns n the rocker arms. And Datsun Parts LLC is now California Datsun. Give him a call. http://www.classiczcars.com/topic/50485-rocker-geometry-woes/page-1 http://www.classiczcars.com/topic/51455-datsun-parts-llc-gone-to-the-dark-side/ Link to comment https://www.classiczcars.com/forums/topic/51681-oil-pressure-uneven/#findComment-472300 Share on other sites More sharing options...
June 19, 20159 yr comment_472302 If there's no oil stains on the floor, that motor is burning it. Could be the rings or the valve seals. Get a loaner compression gauge from your local auto parts and do a compression test. I've read if you don't use the "condom" on the valve stems when installing the seals it causes damage, maybe a slight tear. I've never installed them myself so I'm just repeating what I've read. Link to comment https://www.classiczcars.com/forums/topic/51681-oil-pressure-uneven/#findComment-472302 Share on other sites More sharing options...
June 19, 20159 yr Author comment_472304 Hay Zed head i am in these 2 pages of good reviews i think i will call him,I did send him an E-mail but he is slow on answers Link to comment https://www.classiczcars.com/forums/topic/51681-oil-pressure-uneven/#findComment-472304 Share on other sites More sharing options...
June 19, 20159 yr Author comment_472305 With the first post so as everybody nows I did had to elicoil one of my valve coverhole that was stripped to. Link to comment https://www.classiczcars.com/forums/topic/51681-oil-pressure-uneven/#findComment-472305 Share on other sites More sharing options...
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