Defender Posted January 2, 2020 Share Posted January 2, 2020 The engine has been stood for 12 months or more, started it today and the oil pressure light stayed on so I switched it off after 2 minutes. This has never happened before the light always went out. Should I try priming it and how can I do this on a 3.5 is it coil disconnected and turn it over? I'm waiting on gauge to actually check the pressure but is there anything else I can try in the meantime without causing damage? Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted January 2, 2020 Share Posted January 2, 2020 If you ran it for two minutes with zero oil pressure, in all likelihood you have wiped out your crank and big end bearings, and probably something else. By all means prime the engine and give it a go, but don't get your hopes up, at all. Quote Link to comment Share on other sites More sharing options...
Defender Posted January 2, 2020 Author Share Posted January 2, 2020 18 minutes ago, Bowie69 said: If you ran it for two minutes with zero oil pressure, in all likelihood you have wiped out your crank and big end bearings, and probably something else. By all means prime the engine and give it a go, but don't get your hopes up, at all. OK thanks, I'm kind of guessing on the time it may have been less but I guess any time is bad. Would it have made a noise if this was the case because it didn't sound any different. How will I know after it's primed will it make a horrible racket? Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted January 2, 2020 Share Posted January 2, 2020 Be rather difficult to tell at idle. If you can get the oil warning light to go out when priming then you may find it runs for a while, but be prepared for a rebuild at some point. The other possibility is the oil pressure switch has failed or there is a fault in the wiring - that is best case scenario of course Quote Link to comment Share on other sites More sharing options...
Defender Posted January 2, 2020 Author Share Posted January 2, 2020 Yep I'm hoping it's the switch or wiring too Ok thanks will try and see if I can prime it tomorrow and see what happens. Quote Link to comment Share on other sites More sharing options...
Cynic-al Posted January 3, 2020 Share Posted January 3, 2020 I'm not sure turning it over with the coil disconnected will do any more than running it? On mine I took the dizzy out and made a bar which went down to the top of the oil pump and put it in an electric drill so that I could run thr pump without turning the engine over. You could tell from how hard the drill was working when it was pumping. To make the bar I got a length of steel rod, probably 14mm in diameter, cut a notch in the end then welded a bit of tube around it to hold it on the oil pump. I can have a look through my random bits of metal pile to see if I still have it if you like. If you take the dizzy off make sure you mark the timing. Take the top off and mark where the rotor is and put a scratch between the dizzy and engine so you can get the timing back and dont turn the engine over whilst it's off. Or set it up from scratch again afterwards. I also fitted a pressure gauge as it wasnt great for oil pressure. Quote Link to comment Share on other sites More sharing options...
smallfry Posted January 3, 2020 Share Posted January 3, 2020 Did you change the oil before the run ? Assume you know that you are supposed to change the filter (new one filled) THEN drop the oil and change it, but not both at the same time, as this supposedly causes priming problems. Other than that, a long layoff should make no difference I would imagine that after a long layoff, the tappets would have made a racket on startup, and continued to do so until you shut it down, if there was no oil pressure. If the tappets went quiet, that would mean that you did have pressure, and that the pressure switch is faulty (hopefully) Quote Link to comment Share on other sites More sharing options...
Quagmire Posted January 3, 2020 Share Posted January 3, 2020 I'd go with what Smallfry says - if you had low/no pressure then the tappets would be noisy, especially if its been stood for a while- mine sounds horrendous for a couple of seconds on starting even after a few weeks of being idle. Fingers crossed its just the switch! Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 3, 2020 Share Posted January 3, 2020 1 hour ago, smallfry said: Did you change the oil before the run ? Assume you know that you are supposed to change the filter (new one filled) THEN drop the oil and change it, but not both at the same time, as this supposedly causes priming problems. Other than that, a long layoff should make no difference I never had that problem with the old style oil pumps and oil changes - what I did have a problem with was when I used the wrong grade of oil (too thin) and the damn thing lost prime off-road and wouldn't re-prime until we poured some thicker oil in. I'd check the easy and cheap switch before farting around with anything else though. Quote Link to comment Share on other sites More sharing options...
Defender Posted January 3, 2020 Author Share Posted January 3, 2020 19 hours ago, Cynic-al said: I'm not sure turning it over with the coil disconnected will do any more than running it? On mine I took the dizzy out and made a bar which went down to the top of the oil pump and put it in an electric drill so that I could run thr pump without turning the engine over. You could tell from how hard the drill was working when it was pumping. To make the bar I got a length of steel rod, probably 14mm in diameter, cut a notch in the end then welded a bit of tube around it to hold it on the oil pump. I can have a look through my random bits of metal pile to see if I still have it if you like. If you take the dizzy off make sure you mark the timing. Take the top off and mark where the rotor is and put a scratch between the dizzy and engine so you can get the timing back and dont turn the engine over whilst it's off. Or set it up from scratch again afterwards. I also fitted a pressure gauge as it wasnt great for oil pressure. My thoughts on turning it over with the coil disconnected was that it's not running at 1000rpm with the choke on but I see your point that any turning it over without oil pressure is bad. Thanks for the tips that is good advice, if it's not the switch that bar my come in handy. 9 hours ago, smallfry said: Did you change the oil before the run ? Assume you know that you are supposed to change the filter (new one filled) THEN drop the oil and change it, but not both at the same time, as this supposedly causes priming problems. Other than that, a long layoff should make no difference I would imagine that after a long layoff, the tappets would have made a racket on startup, and continued to do so until you shut it down, if there was no oil pressure. If the tappets went quiet, that would mean that you did have pressure, and that the pressure switch is faulty (hopefully) No it's not been serviced which is why I was confused as there's no reason for no pressure. Yes it doesn't sound noisy so i'm hoping it's just the switch. 7 hours ago, Quagmire said: I'd go with what Smallfry says - if you had low/no pressure then the tappets would be noisy, especially if its been stood for a while- mine sounds horrendous for a couple of seconds on starting even after a few weeks of being idle. Fingers crossed its just the switch! Yep I'm guessing as it's not really noisy it's got to be the switch. 7 hours ago, FridgeFreezer said: I never had that problem with the old style oil pumps and oil changes - what I did have a problem with was when I used the wrong grade of oil (too thin) and the damn thing lost prime off-road and wouldn't re-prime until we poured some thicker oil in. I'd check the easy and cheap switch before farting around with anything else though. Good point switch is £40 and easy enough to change so I will start there, thanks. Thanks for all the replies. I didn't get chance to investigate any further today but will try over the weekend. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 3, 2020 Share Posted January 3, 2020 4 hours ago, Defender said: Good point switch is £40 and easy enough to change so I will start there, thanks. 40 frickin quid, where the hell are you buying your switches? Genuine is £14, aftermarket Allmakes and/or Britpart is £3. Quote Link to comment Share on other sites More sharing options...
muddy Posted January 4, 2020 Share Posted January 4, 2020 7 hours ago, FridgeFreezer said: 40 frickin quid, where the hell are you buying your switches? Genuine is £14, aftermarket Allmakes and/or Britpart is £3. Xxxxxxxxtreme innit 😎 Quote Link to comment Share on other sites More sharing options...
smallfry Posted January 4, 2020 Share Posted January 4, 2020 Or is it one that runs an electric pressure gauge ? Quote Link to comment Share on other sites More sharing options...
Defender Posted January 4, 2020 Author Share Posted January 4, 2020 Yep it's a three pin one 589470 Found one of the wires to the switch covered in insulation tape and on further investigation it appears that the wire's have been joined, so it's looking like a bad connection! Thanks again for all your help everyone. Quote Link to comment Share on other sites More sharing options...
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