Discussion
Quick question - what should the oil pressure be at certain revs?
Say at 900rpm, mine's between 21-25psi
Although at higher rpm, ie 5500rpm it's running in the late 30's, as in 39psi
Does this sound correct, or should it be 47-48psi at higher revs?
Reason I ask is that I'm sure I say an oil light flicker on Saturday, but I've not seen it since - could be engine poping paranoya!
Say at 900rpm, mine's between 21-25psi
Although at higher rpm, ie 5500rpm it's running in the late 30's, as in 39psi
Does this sound correct, or should it be 47-48psi at higher revs?
Reason I ask is that I'm sure I say an oil light flicker on Saturday, but I've not seen it since - could be engine poping paranoya!
I had a loan Tuscan where the oil light came on at high RPM but no alert came up on the pod. I changed the oil pressure sender which made no difference. The factory asked me not to drive it and get it recovered back to them, as they were concerned about engine damage.
If your oil light is coming on I suggest getting it checked out before driving any further. tvr5000 is right, it could save you a big bill.
If your oil light is coming on I suggest getting it checked out before driving any further. tvr5000 is right, it could save you a big bill.
Guys,
The handbook for my 'S' suggests the pressure should not drop below 32 psi at 2000rpm. I am not convinced that the senders are at all accurate across the board also not that sure of the performance of the pumps across the board either. I asked a similar question a while back on another forum and the feed back resulted in all sorts of readings from other owners (I did ask for all engines to be warmed up from cold and reading to be taken at 2000rpm). Oil type used also has some influence.
If you want to test it yourself rather than take it to a dealer. Get hold of a mechanical oil gauge (not electronic, you could use one of these but its more expensive), the likes of which Demon Tweeks supply. Remove the engine oil pressure sensor and fit the adaptor and tubing that will come with the mechanical gauge then run the car on the driveway (you will likely get the fault code J display).
Such a test will go towards giving you an indication as to whether the pressure is healthy or not. (You are best off using a new gauge rather than one that has been bounced around in the bottom of a spares or tool box). Any 0-100 psi bourdon tube gauge should suffice, but getting the right adaptors will be more difficult this route. BUT NEVER use a gauge that has been, or will be used on oxygen (such as oxy/acetelene welding/cutting equipment) the likely resultant explosion will be somewhat startling....
Regards
G
The handbook for my 'S' suggests the pressure should not drop below 32 psi at 2000rpm. I am not convinced that the senders are at all accurate across the board also not that sure of the performance of the pumps across the board either. I asked a similar question a while back on another forum and the feed back resulted in all sorts of readings from other owners (I did ask for all engines to be warmed up from cold and reading to be taken at 2000rpm). Oil type used also has some influence.
If you want to test it yourself rather than take it to a dealer. Get hold of a mechanical oil gauge (not electronic, you could use one of these but its more expensive), the likes of which Demon Tweeks supply. Remove the engine oil pressure sensor and fit the adaptor and tubing that will come with the mechanical gauge then run the car on the driveway (you will likely get the fault code J display).
Such a test will go towards giving you an indication as to whether the pressure is healthy or not. (You are best off using a new gauge rather than one that has been bounced around in the bottom of a spares or tool box). Any 0-100 psi bourdon tube gauge should suffice, but getting the right adaptors will be more difficult this route. BUT NEVER use a gauge that has been, or will be used on oxygen (such as oxy/acetelene welding/cutting equipment) the likely resultant explosion will be somewhat startling....
Regards
G
Just to confuse matters… I *think* it is possible for the pressure being displayed on the pod to be normal, yet there can still be a problem. On the Tuscan I mentioned above the pressure on the digital readout was fine, yet the oil light came on at high RPM. On my Sagaris the oil pressure on the digital readout has been far too low due to a duff sender, yet the oil light never came on. Does anybody know where the red oil light takes it feed from? And how does it decide when to come on?
I started having this problem before my last service. (i.e. the oil pressure would be at around 10psi at tick over, and never get above 25psi, no matter how much it was revved). At 3100 rpm the oil light would come on, and would not go off until the revs dropped below 3100 again.
The dealer assured me it was nothing to do with the engine, and to corroborate this it is not burning any more or less that it used to, nor is it leaking any - I have no way of measuring how well the pump is working though. They changed the pressure switch out at its service and it was fine for about 200 miles, but has been wrong since then (about 2500 miles ago). I have now resorted to a classic TVR fix - small piece of black gaffer tape over the red light!
I have since moved down south, and County TVR have said that they will post me another oil pressure switch when they got one in stock, as they agree that it is almost definitely this (they are so unreliable that the factory has run out apparently).
The way the light is controlled, as was explained to me is as follows. Programmed into the ECU is effectively a graph of load/rpm against oil pressure values. There is a tolerance for any particular point on the graph, and if the computer detects a devation of more than the tolerance between the expected output and the reading from the sensor it turns on the oil pressure warning light.
What I have discovered (although this is my own deduction only, so don't quote me on this) is that the !WARNING! read-out on the dashboard is less intelligent and only pops up if the pressure drops below 4 or 5 psi regardless of the load on the engine. Bizarrely, however, at this pressure at idle the oil pressure light DOESN'T come on, presumably because the ECU reckons that at 700rpm the (hot) oil could conceivably be as low as 2 or 1 or even 0 psi (
).
It all sounds a bit cobbled together to me, and an overly complex arrangement. I'm beginning to think that I'd far rather have a mechanical gauge, as when the little red light comes on, my natural instinct is always to panic first, think second.
The dealer assured me it was nothing to do with the engine, and to corroborate this it is not burning any more or less that it used to, nor is it leaking any - I have no way of measuring how well the pump is working though. They changed the pressure switch out at its service and it was fine for about 200 miles, but has been wrong since then (about 2500 miles ago). I have now resorted to a classic TVR fix - small piece of black gaffer tape over the red light!
I have since moved down south, and County TVR have said that they will post me another oil pressure switch when they got one in stock, as they agree that it is almost definitely this (they are so unreliable that the factory has run out apparently).
The way the light is controlled, as was explained to me is as follows. Programmed into the ECU is effectively a graph of load/rpm against oil pressure values. There is a tolerance for any particular point on the graph, and if the computer detects a devation of more than the tolerance between the expected output and the reading from the sensor it turns on the oil pressure warning light.
What I have discovered (although this is my own deduction only, so don't quote me on this) is that the !WARNING! read-out on the dashboard is less intelligent and only pops up if the pressure drops below 4 or 5 psi regardless of the load on the engine. Bizarrely, however, at this pressure at idle the oil pressure light DOESN'T come on, presumably because the ECU reckons that at 700rpm the (hot) oil could conceivably be as low as 2 or 1 or even 0 psi (
). It all sounds a bit cobbled together to me, and an overly complex arrangement. I'm beginning to think that I'd far rather have a mechanical gauge, as when the little red light comes on, my natural instinct is always to panic first, think second.
Interesting reading 
I've just checked mine again, it doesn't go over 40psi, or drop below 20psi. 2000rpm is 35psi where is sort of stays as you increase the revs. It had a rebuild in April BTW.
Red oil light has not come on at all, in 1st, 2nd, 3rd gears, and it's not using any oil
It's due a service in a couple of weeks, I'll pootle down there to check it out
I've just checked mine again, it doesn't go over 40psi, or drop below 20psi. 2000rpm is 35psi where is sort of stays as you increase the revs. It had a rebuild in April BTW.
Red oil light has not come on at all, in 1st, 2nd, 3rd gears, and it's not using any oil
It's due a service in a couple of weeks, I'll pootle down there to check it out
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