max-ie Posted May 5, 2009 Share Posted May 5, 2009 Hi, I've done a search and can't find the answer. I've got a 3.5 V8 EFI fitted in my 90. The oil pressure warning light isn't working. I've checked the bulb in the instrument binacle and its ok. I've checked the oil pressure switch with a multi tester and thats ok also. I'm worried that there's not alot of oil pressure as the engine has started to be noisey at the top end on cold start . Is there an easy check i can make to check the pressure, i intend buying a gauge for the cab but not just yet as i don't know what type to get or how it all fits. The 90 isn't on the road yet and has been standing for a while so could probably do with oil and filter change. Theres plenty in it at the moment and its must have been changed soon before i bought it as the oil isn't black yet. Any replies appreciated thanks Max Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted May 5, 2009 Share Posted May 5, 2009 If the switch works and the bulb works there is only the wire in between them to go wrong you should have ignition switched 12v to the bulb and then from the other side of the bulb to the switch, which will short to ground when the oil pressure is low. Quote Link to comment Share on other sites More sharing options...
plank22 Posted May 5, 2009 Share Posted May 5, 2009 Hi, I've done a search and can't find the answer. I've got a 3.5 V8 EFI fitted in my 90. The oil pressure warning light isn't working. I've checked the bulb in the instrument binacle and its ok. I've checked the oil pressure switch with a multi tester and thats ok also. I'm worried that there's not alot of oil pressure as the engine has started to be noisey at the top end on cold start . Is there an easy check i can make to check the pressure, i intend buying a gauge for the cab but not just yet as i don't know what type to get or how it all fits. The 90 isn't on the road yet and has been standing for a while so could probably do with oil and filter change. Theres plenty in it at the moment and its must have been changed soon before i bought it as the oil isn't black yet. Any replies appreciated thanks Max so is the warning light working or not cos you said you tested that and the sender and you said both were ok? If you intend to buy a gauge then just get one now, not hard to fit and will give you an answer. Make sure the one you get comes all the gubbins you need whick will be the gauge, length of copper microbore and a T piece. The T piece goes in where the sender is and the sender goes back in on the other side of the T. All very easy it all screws together. I got TIM gauges from deamon freaks. Quote Link to comment Share on other sites More sharing options...
max-ie Posted May 6, 2009 Author Share Posted May 6, 2009 I'm presuming there's something wrong with the wiring.. I will have a look on my days off. I've looked at the switch and it appears to screw into a plastic fitting so not sure how it would ground out. I was just wondering if there was a quick check that i could do to see if there was any pressure there. Max Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted May 6, 2009 Share Posted May 6, 2009 I'm presuming there's something wrong with the wiring.. I will have a look on my days off. I've looked at the switch and it appears to screw into a plastic fitting so not sure how it would ground out. I was just wondering if there was a quick check that i could do to see if there was any pressure there.Max So if you can't work out how the switch would ground out, how have you confirmed it's working, being that when it's working (light on) it grounds the connection to the engine block? Quote Link to comment Share on other sites More sharing options...
zim Posted May 7, 2009 Share Posted May 7, 2009 I'm presuming there's something wrong with the wiring.. I will have a look on my days off. I've looked at the switch and it appears to screw into a plastic fitting so not sure how it would ground out. I was just wondering if there was a quick check that i could do to see if there was any pressure there.Max Has it ever worked ? Because, from what you describe "screw into a plastic fitting", are you sure you aren't suposed to have a gauge instead - as the sender for a gauge is a whole lot bigger (looks like an old camera film plastic tub almost, but white / orange / some other colour they had in stock when manufacturing lol)....whereas the sender for just an on/off bulb is relatively flat / small. G A picture is as good as a million words : This is the on/off sender : This is the oil temp sender, found in the same housing : This is for an oil pressure gauge : I guess, from your description, the first switch is kind of in a plastic housing, but that is only the spade connector which your wire connects to, but the actual item what screws into the block is metallic. To test, turn your key on.... take the wire off your sender, and touch it to earth - your light should come on. If it does, your sender is kaput. Hope that helps Gordon Edit again : thinking about it, if you had the sensor for a gauge then your light would probably be on dim then brightening up etc as the pressure changed.... so i think i was jumping the gun a bit. Quote Link to comment Share on other sites More sharing options...
max-ie Posted May 7, 2009 Author Share Posted May 7, 2009 Hi, thanks for the above replies, I checked the on /off switch with a multi tester set on continuity setting and the switch breaks ok. I've now put the wire off this tab to ground and the oil light in the cab comes on. The oil light has not worked since i put the EFI engine in. I have also tried to ground the case of the switch whilst its all connected up and the light won't come on. I assume that the switch itself is broken even though it shows ok on continuity test. Cheers Max Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted May 7, 2009 Share Posted May 7, 2009 Sounds like your switch is broken then, a multimeter might not poke enough current through the switch on the ohms scale to show up the fault. Grounding the body of the switch is unlikely to do much what with it being screwed directly into the big grounded lump of aluminium that is your engine Quote Link to comment Share on other sites More sharing options...
tillmannz Posted May 8, 2009 Share Posted May 8, 2009 I changed threetimes the on/off type sender at my car.But that is unretentive. I bought a VDO mechanical oil pressure gauge, plus two meter copperpipe.This is the best .If the motor run and oil is in pipe,then the gauge show the pressure. Quote Link to comment Share on other sites More sharing options...
max-ie Posted May 12, 2009 Author Share Posted May 12, 2009 New switch fitted and now working fine, thanks for the help lads Max Quote Link to comment Share on other sites More sharing options...
istruggle2gate11 Posted May 12, 2009 Share Posted May 12, 2009 New switch fitted and now working fine, thanks for the help ladsMax If its a britpart one, dont be surprised if its dead in a month! - Genuine part purchase everytime for me. Quote Link to comment Share on other sites More sharing options...
nikiboy Posted May 30, 2009 Share Posted May 30, 2009 I have bad experience in the past with the oil pressure ) So now I put to my 3.5 RR a guide and scale from Lada. It is very cheap - less that 5-7 Euro both. You need just a small transformation of the treath from 4x1.25 to imperial. This is the guide The connection is: - Orange - it is "+" - white/black- it is "-" - Right free place is the signal 300-320 oms = 0 bar 50-60 oms = 8 bars Quote Link to comment Share on other sites More sharing options...
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