Engine Oil pressure?
Discussion
I've recently brought an M reg TVR chim 4ltr and am having some serious fun it, with just one concern.
Before I purchased the car I noticed the low oil pressure light was on. When I asked the owner about this he said that it had been like that for as long as he had owned it. (which was about four years) I rightfully got him to reduce his asking price due to the fault.
Anyway, I have now become obsessed with looking at the analogue oil pressure gauge and wondered if anyone could advise as to what pressure I should be getting on the gauge? My gauge reads as follows:
On start up and Idling when cold, Between 15-30 lbs.
Idling when warm, between 5-15lbs.
When warm and rpm from 1400-3000, between 15-30 lbs.
When warm and rpm over 3000, just over 30lbs.
Is this the norm?
Some figures to compare to would be useful so that I can either go and buy a new oil pump or start watching the road when driving instead of this gauge.
Before I purchased the car I noticed the low oil pressure light was on. When I asked the owner about this he said that it had been like that for as long as he had owned it. (which was about four years) I rightfully got him to reduce his asking price due to the fault.
Anyway, I have now become obsessed with looking at the analogue oil pressure gauge and wondered if anyone could advise as to what pressure I should be getting on the gauge? My gauge reads as follows:
On start up and Idling when cold, Between 15-30 lbs.
Idling when warm, between 5-15lbs.
When warm and rpm from 1400-3000, between 15-30 lbs.
When warm and rpm over 3000, just over 30lbs.
Is this the norm?
Some figures to compare to would be useful so that I can either go and buy a new oil pump or start watching the road when driving instead of this gauge.
Probably not what you want to hear, but those pressures are all a bit on the low side.
Not 'imminent-risk-of-engine-seizure' low, but certainly 'start-saving-up-for-a-rebuild' low; the Bible (born out by my admittedly limited experience) offers:
10-15 psi minimum hot idle
25-40 psi at revs (I've seen a bit more - up to 50 psi at revs.)
It also gives the sensible (and normal for pretty much any engine) advice: If the oil pressure drops below 10 lbs/sq. in. then stop the engine immediately
If you are genuinely getting 5 psi at hot idle (and it may just be a faulty sender, gauge or wiring), then it's time to start worrying a little.
Edited to add: Someone with more experience of the Rover V8 may wish to correct me, but typically the oil pressure warning switches on most engines are set to illuminate the warning light if the pressure drops below about 10 psi (though you can get 'high pressure' ones which illuminate if pressure drops below about 28 psi, to give advanced warning of oil pressure loss). If your hot idle pressure is dropping below 10 psi and the oil pressure warning light is only on at idle (rather than all the time), it may well be doing its job correctly.
>> Edited by Martin_S on Thursday 24th March 21:57
Not 'imminent-risk-of-engine-seizure' low, but certainly 'start-saving-up-for-a-rebuild' low; the Bible (born out by my admittedly limited experience) offers:
10-15 psi minimum hot idle
25-40 psi at revs (I've seen a bit more - up to 50 psi at revs.)
It also gives the sensible (and normal for pretty much any engine) advice: If the oil pressure drops below 10 lbs/sq. in. then stop the engine immediately
If you are genuinely getting 5 psi at hot idle (and it may just be a faulty sender, gauge or wiring), then it's time to start worrying a little.
Edited to add: Someone with more experience of the Rover V8 may wish to correct me, but typically the oil pressure warning switches on most engines are set to illuminate the warning light if the pressure drops below about 10 psi (though you can get 'high pressure' ones which illuminate if pressure drops below about 28 psi, to give advanced warning of oil pressure loss). If your hot idle pressure is dropping below 10 psi and the oil pressure warning light is only on at idle (rather than all the time), it may well be doing its job correctly.
>> Edited by Martin_S on Thursday 24th March 21:57
Hi'
I wouldnt become obsessed with your oil pressure issue as that will certainly effect your enjoyment, although it does appear a little on the low side. First of all, do you now what grade engine oil you have, because if it is one of the lower viscocity oils , eg Mobil 0-40 that could be a little thin for a worn engine, it maybe a good idea to change it for a thicker oil, for example a 15-50, or castrol do a 10-60 if you can find it.Also have you noticed excessive oil consumption? its not unusual for the RV8 to consume a little, but if you are constantly topping and there are no obvious leaks, then that may suggest excessive bore or top end wear. I think I am correct in saying these big V8 engines can run quite happily on lower pressures, more cause for concern would be any sudden drop in pressure for no obvious reason.
I wouldnt become obsessed with your oil pressure issue as that will certainly effect your enjoyment, although it does appear a little on the low side. First of all, do you now what grade engine oil you have, because if it is one of the lower viscocity oils , eg Mobil 0-40 that could be a little thin for a worn engine, it maybe a good idea to change it for a thicker oil, for example a 15-50, or castrol do a 10-60 if you can find it.Also have you noticed excessive oil consumption? its not unusual for the RV8 to consume a little, but if you are constantly topping and there are no obvious leaks, then that may suggest excessive bore or top end wear. I think I am correct in saying these big V8 engines can run quite happily on lower pressures, more cause for concern would be any sudden drop in pressure for no obvious reason.
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