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Thanks, i think i remember some of those videos now I've seen them again
Calling all oil-pressure experts!
- Thread starter paul.adshead
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paul.adshead
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It think Island4x4 just has it listed wrong (- at least according to what LR planned to do).
My belief, is that the sump mating face on the V8 was a well known 'leaker' on the RR Classic and D1. For the start of the P38 (i.e. GEMS) LR kept the same steel sump but used sealant to hopefully stop the leaks. For the later 99-02 P38, they changed to an ali sump with rubber gasket (and RAVE says to also use sealant with that too).
paul.adshead
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[<videos>
And have a read...
https://www.landyzone.co.uk/land-rover/main-and-big-end-bearing-replacement-gems-v8.271468/
Thanks, I'll go through that and work out what I can.
paul.adshead
Member
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Hi Guys.
So I bought a replacement o-ring and fitted it. Problem solved.
As I tried to describe a few posts back, I am guessing that the o-ring pickup must have been leaking, allowing what was around the connection, into the pump. When the oil is cold, it is sticky enough to nearly seal the area. When the oil is hot but RPM high, there is enough 'sump splash' to be continuously coating the o-ring area, minimising the effects of the leak. When the oil is hot, but idle RPM for 30+ seconds, then the hot oil more easily drains off the surfaces, exposing some/all of the o-ring area, then allowing crankcase vapours into the pump. This makes the pump partially 'loose it's prime', meaning it can't supply as much pressure whilst also feeding air into the oil system. At some point the air in the system causes the back-pressure to drop, allowing the pump to fully re-prime, whereby the pressure rises again. This just keeps on cycling.
Interestingly, the oil pressure warning light, is tripped at VERY low pressure (a couple of psi). So whilst the pressure was oscillating around, you wouldn't know it, just by looking at the warning light. As such, I suspect MANY vehicles have this issue, as it is a silent failure - you just wouldn't know unless you have added additional oil monitoring gauges!!
So I bought a replacement o-ring and fitted it. Problem solved.
As I tried to describe a few posts back, I am guessing that the o-ring pickup must have been leaking, allowing what was around the connection, into the pump. When the oil is cold, it is sticky enough to nearly seal the area. When the oil is hot but RPM high, there is enough 'sump splash' to be continuously coating the o-ring area, minimising the effects of the leak. When the oil is hot, but idle RPM for 30+ seconds, then the hot oil more easily drains off the surfaces, exposing some/all of the o-ring area, then allowing crankcase vapours into the pump. This makes the pump partially 'loose it's prime', meaning it can't supply as much pressure whilst also feeding air into the oil system. At some point the air in the system causes the back-pressure to drop, allowing the pump to fully re-prime, whereby the pressure rises again. This just keeps on cycling.
Interestingly, the oil pressure warning light, is tripped at VERY low pressure (a couple of psi). So whilst the pressure was oscillating around, you wouldn't know it, just by looking at the warning light. As such, I suspect MANY vehicles have this issue, as it is a silent failure - you just wouldn't know unless you have added additional oil monitoring gauges!!
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Hi Guys.
So I bought a replacement o-ring and fitted it. Problem solved.
As I tried to describe a few posts back, I am guessing that the o-ring pickup must have been leaking, allowing what was around the connection, into the pump. When the oil is cold, it is sticky enough to nearly seal the area. When the oil is hot but RPM high, there is enough 'sump splash' to be continuously coating the o-ring area, minimising the effects of the leak. When the oil is hot, but idle RPM for 30+ seconds, then the hot oil more easily drains off the surfaces, exposing some/all of the o-ring area, then allowing crankcase vapours into the pump. This makes the pump partially 'loose it's prime', meaning it can't supply as much pressure whilst also feeding air into the oil system. At some point the air in the system causes the back-pressure to drop, allowing the pump to fully re-prime, whereby the pressure rises again. This just keeps on cycling.
Interestingly, the oil pressure warning light, is tripped at VERY low pressure (a couple of psi). So whilst the pressure was oscillating around, you wouldn't know it, just by looking at the warning light. As such, I suspect MANY vehicles have this issue, as it is a silent failure - you just wouldn't know unless you have added additional oil monitoring gauges!!
Yeah, that o-ring has caught out some very experienced members in the past.
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You just won't drop it will you...jezzz....Yeah, that o-ring has caught out some very experienced members in the past.
only kidding - much respect to you and your brother....
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