Discussion
Hi guys I have a problem with my oil pressure or something!
When I turn on the ignition the gauge goes straight to the top reading 100, then I start the engine and it goes straight to the bottom reading 0, what am I to do!
I don’t want to drive it until it gets sorted.
I have changed the sender and the gauge its self but its still doing the same thing.
Any ideas anyone?
Thanks, jonny g
When I turn on the ignition the gauge goes straight to the top reading 100, then I start the engine and it goes straight to the bottom reading 0, what am I to do!
I don’t want to drive it until it gets sorted.
I have changed the sender and the gauge its self but its still doing the same thing.
Any ideas anyone?
Thanks, jonny g
Jonny, firstly your oil pressure will be ok its an electrical problem so to drive her will not be a problem. Unfortunately I'm at work so cannot get to 'bible' for wiring details. I am sure someone who is not out enjoying a blat will be along soon with the details of which gauge terminal should be live which has the sender wire and which is the earth. You will need a cheap multimeter to prove.
bible suggests the oil pressure gauge has three terminals,
colour coding to wiring being;
(B) black, connects to all gauges and then to earth
(G) green, connects to all gauges, live feed to gauge illumination
(WN)white brown (behind dash) turniing to (UG) blue green in engine bay, connects gauge to sender unit.
have you tried doing a continuity check on the sender wire ie between connection to sender and gauge terminal? to ensure its not a broken wire /poor connection at some point.
bil
colour coding to wiring being;
(B) black, connects to all gauges and then to earth
(G) green, connects to all gauges, live feed to gauge illumination
(WN)white brown (behind dash) turniing to (UG) blue green in engine bay, connects gauge to sender unit.
have you tried doing a continuity check on the sender wire ie between connection to sender and gauge terminal? to ensure its not a broken wire /poor connection at some point.
bil
I'd bet that you have the wrong sender and actually have low oil pressure switch that would normally be fitted to these cars and is used to illuminate a dash warning light in the event of low oil pressure.
My reasoning being....
You turn on the ignition and get full scale deflection. This means that the gauge is getting full voltage because the switch is on because at that time the oil pressure is zero. Start it up and the oil pressure goes to a safe level so the switch turns off and the gauge drops to zero.
So while you have no reading on the gauge you're safe but it is nicer to see what the OP really is.
Edit: Whan I say oil pressure switch I mean one with just ON/OFF states and not a variable output as an oil pressure sender would give.
My reasoning being....
You turn on the ignition and get full scale deflection. This means that the gauge is getting full voltage because the switch is on because at that time the oil pressure is zero. Start it up and the oil pressure goes to a safe level so the switch turns off and the gauge drops to zero.
So while you have no reading on the gauge you're safe but it is nicer to see what the OP really is.
Edit: Whan I say oil pressure switch I mean one with just ON/OFF states and not a variable output as an oil pressure sender would give.
Edited by Jed-S on Monday 13th August 18:00
Jed-S said:
I'd bet that you have the wrong sender and actually have low oil pressure switch that would normally be fitted to these cars and is used to illuminate a dash warning light in the event of low oil pressure.
My reasoning being....
You turn on the ignition and get full scale deflection. This means that the gauge is getting full voltage because the switch is on because at that time the oil pressure is zero. Start it up and the oil pressure goes to a safe level so the switch turns off and the gauge drops to zero.
So while you have no reading on the gauge you're safe but it is nicer to see what the OP really is.
Edit: Whan I say oil pressure switch I mean one with just ON/OFF states and not a variable output as an oil pressure sender would give.
I'd been trying to puzzle this out today - I think you are exactly right about the switch, good thinking. My reasoning being....
You turn on the ignition and get full scale deflection. This means that the gauge is getting full voltage because the switch is on because at that time the oil pressure is zero. Start it up and the oil pressure goes to a safe level so the switch turns off and the gauge drops to zero.
So while you have no reading on the gauge you're safe but it is nicer to see what the OP really is.
Edit: Whan I say oil pressure switch I mean one with just ON/OFF states and not a variable output as an oil pressure sender would give.
Edited by Jed-S on Monday 13th August 18:00
I'd also suggest that as the switch (instead of the sender) is giving the symptoms you describe then it sounds likely to me that everything is in order - you just have the wrong sender as Jed-S said.
spivvy is quite correct, you need to get one from TVR Carparts it is a special. Also we should not get too precious about oil pressures etc, we have had very few engine failures recorded on PH over the years.
My gauge went on the blink 18 months ago so I got really paranoid about oil pressure and impending wrecked engine until I rationalised that what sits up front is a Ford concrete block, nigh on bomb proof.
Gauge watching was ruining the driving experience, until I fitted the new sender and realised I had no wire to reconnect, 'cos the bloody thing had broken off due to the exhaust heat. So I left it and do not worry about it any more, it is absolutely fine, but then mine is a daily driver so I am more used to it and less nervous than most.
Uncle Henry and most other manufacturers have got us sussed, give 'em a little light as a warning then they won't get too bothered.
After all we aint got a 'rrari cash gobbler up front!
YB
My gauge went on the blink 18 months ago so I got really paranoid about oil pressure and impending wrecked engine until I rationalised that what sits up front is a Ford concrete block, nigh on bomb proof.
Gauge watching was ruining the driving experience, until I fitted the new sender and realised I had no wire to reconnect, 'cos the bloody thing had broken off due to the exhaust heat. So I left it and do not worry about it any more, it is absolutely fine, but then mine is a daily driver so I am more used to it and less nervous than most.
Uncle Henry and most other manufacturers have got us sussed, give 'em a little light as a warning then they won't get too bothered.
After all we aint got a 'rrari cash gobbler up front!
YB
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