Does anyone know at what pressure the release valve operates?
Before being put into storage at the end of last Summer my car ran with normal oil pressures, generally about 50 psi when running hot.
For some unknown reason it now wants to run at 90 psi most of the time. Its like someone turned on a switch to just about double the pressure!!
I put in a new oil pump, two new filters, changed the oil from 20/50 to 10/30, tried two other oil gauges including a calibrated capillary gauge and
took the head off to ensure no blockages to all accessible oil galleries.
Looks like I now need the experts. Please help.
Pressure relief valve stuck shut?
(I have zero Pinto experience, but all engines have a oil PRV to moderate pressure)
Thanks, but as far as I know the pressure relief valve is part of the pump assembly, which was replaced in its entirety. Difficult to believe that
both the existing and replacement pumps have the same issue
Does anyone know at what pressure the release valve operates?
It will be a stuck oil pressure relief valve , it's the only thing to control the oil pressure
quote:
Originally posted by rusty nuts
It will be a stuck oil pressure relief valve , it's the only thing to control the oil pressure
Just a guess is the pipe over the cam ok
I know you say the valve is new but that’s does not mean to say it’s ok
Did you swop the pump like for like not a high capacity
Graham
[Edited on 11/4/21 by jacko]
First thing to do is confirm the oil pressure by fitting a test gauge. Most garages will have one. More often than not its the gauge is incorrect. If its an electronic gauge check the wiring and earthing.
quote:
Originally posted by Mr Whippy
First thing to do is confirm the oil pressure by fitting a test gauge. Most garages will have one. More often than not its the gauge is incorrect. If its an electronic gauge check the wiring and earthing.
quote:
Originally posted by jacko
Just a guess is the pipe over the cam ok
I know you say the valve is new but that’s does not mean to say it’s ok
Did you swop the pump like for like not a high capacity
Graham
[Edited on 11/4/21 by jacko]
quote:
Originally posted by Mr Whippy
First thing to do is confirm the oil pressure by fitting a test gauge. Most garages will have one. More often than not its the gauge is incorrect. If its an electronic gauge check the wiring and earthing.
quote:
Originally posted by David Jenkins
quote:
Originally posted by Mr Whippy
First thing to do is confirm the oil pressure by fitting a test gauge. Most garages will have one. More often than not its the gauge is incorrect. If its an electronic gauge check the wiring and earthing.
That was my thought - it could be a faulty oil pressure gauge or sender. Can you scrounge one from somewhere, just to try it out? Doesn't have to be anything grand, or calibrated, just a cheapo gauge to see whether it still shows an abnormally high pressure.
A standard oil pump works at 60psi at 6000 rpm a high pressure oil pump is 90psi
So I have just read on classic Ford forum
As a matter of interest where did you buy the new pump as I have just read burtons sell high pressure pumps
Graham
[Edited on 11/4/21 by jacko]
quote:
Originally posted by bumpy
You must have missed that that has already been done (first post)
quote:
Originally posted by jacko
A standard oil pump works at 60psi at 6000 rpm a high pressure oil pump is 90psi
So I have just read on classic Ford forum
As a matter of interest where did you buy the new pump as I have just read burtons sell high pressure pumps
Graham
[Edited on 11/4/21 by jacko]
quote:
Originally posted by bumpy
quote:
Originally posted by jacko
A standard oil pump works at 60psi at 6000 rpm a high pressure oil pump is 90psi
So I have just read on classic Ford forum
As a matter of interest where did you buy the new pump as I have just read burtons sell high pressure pumps
Graham
[Edited on 11/4/21 by jacko]
It was indeed a Burtons pump OP1
https://www.burtonpower.com/std-oil-pump-sohc-ford-pinto-e scort-cosworth-t25-op01.html
Still doesn't answer the question why a car that ran all last year at normal oil pressures should suddenly double its oil pressure when re-started this Spring, when absolutely nothing had been changed ?????
Have you stripped old pump and checked relief valve piston?
Looks like the only thing you can do is sump off and check the relief valve there is nothing else that I can think of to cause your problem
Unless some one can think of something else
Graham
Still doesn't answer the question why a car that ran all last year at normal oil pressures should suddenly double its oil pressure when re-started this Spring, when absolutely nothing had been changed ?????
quote:
Originally posted by jacko
Still doesn't answer the question why a car that ran all last year at normal oil pressures should suddenly double its oil pressure when re-started this Spring, when absolutely nothing had been changed ?????
Old PRV was taken apart, and no sign whatsoever of it sticking
Well if you think it isn’t the valve I don’t know what it could be faulted oil gauge maybe but you say you checked that
Graham
Does the engine sound rattly as if its starving of oil? If so, something could be blocking the galleries close to the pump.
Wasn't there some issue with Burtons oil pumps? Seem to remember something about the galleries not lining up properly that o read something about a while ago. Probably on a ford forum..
Did you put gasket past in-between the pump and pick up or pump to block ? If so it could have part blocked a gallery
[Edited on 13/4/21 by jacko]
@Bumpy
Can you repost EXCACTLY what has been changed on or in the engine since the oil pressure was around 50psi until now its 90psi
I have had similar problems on a xflow, when the Prv wouldnt open but was more around 70psi at tickover
quote:
Originally posted by r1_pete
Does the engine sound rattly as if its starving of oil? If so, something could be blocking the galleries close to the pump.
quote:
Originally posted by jacko
Did you put gasket past in-between the pump and pick up or pump to block ? If so it could have part blocked a gallery
[Edited on 13/4/21 by jacko]
quote:
Originally posted by steve m
@Bumpy
Can you repost EXCACTLY what has been changed on or in the engine since the oil pressure was around 50psi until now its 90psi
I have had similar problems on a xflow, when the Prv wouldnt open but was more around 70psi at tickover
Considering the pressure relief valve.
Old pump and new pump gave exactly the same readings
Specs say the PRV should open between 58 and 68 psi.
I guess that it is opening OK, and that pressure shown above this is because the pump must be designed to give some oil pressure within the engine
even then. If this were not the case then nobody would have an oil pressure reading of greater than 68psi ever.
[Edited on 14/4/21 by bumpy]
[Edited on 14/4/21 by bumpy]
[Edited on 14/4/21 by bumpy]
The prv opens when the pressure exceeds the specified amount. It then maintains that limit pressure. The only way you can get higher pressure is if it doesn't open/operate
quote:
Originally posted by adithorp
The prv opens when the pressure exceeds the specified amount. It then maintains that limit pressure. The only way you can get higher pressure is if it doesn't open/operate
“ When you have eliminated the impossible, whatever remains, however improbable, must be the truth”
quote:
Originally posted by adithorp
The prv opens when the pressure exceeds the specified amount. It then maintains that limit pressure. The only way you can get higher pressure is if it doesn't open/operate
quote:
Originally posted by bumpy
quote:
Originally posted by adithorp
The prv opens when the pressure exceeds the specified amount. It then maintains that limit pressure. The only way you can get higher pressure is if it doesn't open/operate
So are you saying that any pinto engine that shows a pressure reading higher than 68 psi (which is the upper spec of the PRV) has a fault?
If this is the case I suspect there will be a lot of worried owners out there.
quote:
Originally posted by bumpy
Old PRV was taken apart, and no sign whatsoever of it sticking
Nope neither pump had been tampered with. Namely an old one that spontaneously doubled its reading after a winter storage in a garage, and a brand now
one from Burtons.
[Edited on 15/4/21 by bumpy]
So lets have a recap on what i believe has gone on here
Car and Engine last year ran perfectly, good normal oil pressure conducive with a Pinto engine
NOTHING HAS BEEN DONE TO THE ENGINE since last year ? and i really do mean NOTHING
Yet this year on first start up, the oil pressure has jumped to 90psi and remains there ?
and even with a NEW pump, the pressure is still 90 psi ?
From this we can discount the oil pumps, if two have been used, and verified by a couple of different guages,
and you say you replaced the two filters, why has your engine got two ?as ive never come across that,
The spin off filters have a valve in them, and i wonder if the one you have fitted is faulty (not sure how) but apart from OIL, and TWO ? Filters that
is the only work on the engine from last year, so i believe
My last point is, that running 90psi on the oil system is going to play havoc with the crankshaft end seals, but at least on a Pinto the spray bar and
valve train should be good !!
We seem to have got caught in a cyclic discussion where blame has been put on the PRV, so I would like to explore this problem from a different angle
if possible.
On the Pinto engine the Ford Motor Company and Autodata books specify an oil pressure of 37psi at 2000rpm with hot oil. This is a stated fact.
Now under just those conditions, my engine pressure, using a variety of matched senders and gauges, reads 75-80psi.
At the normal 37psi the PRV is not called into play at all, as its lower working limit of 58psi has not been reached. So even if it was welded shut it
would have no impact at all on that reading and cant be responsible for the 75-80psi
So I think we need to consider alternative possibilities for the high readings.
quote:
Originally posted by steve m
So lets have a recap on what i believe has gone on here
Car and Engine last year ran perfectly, good normal oil pressure conducive with a Pinto engine
NOTHING HAS BEEN DONE TO THE ENGINE since last year ? and i really do mean NOTHING
Yet this year on first start up, the oil pressure has jumped to 90psi and remains there ?
and even with a NEW pump, the pressure is still 90 psi ?
From this we can discount the oil pumps, if two have been used, and verified by a couple of different guages,
and you say you replaced the two filters, why has your engine got two ?as ive never come across that,
The spin off filters have a valve in them, and i wonder if the one you have fitted is faulty (not sure how) but apart from OIL, and TWO ? Filters that is the only work on the engine from last year, so i believe
My last point is, that running 90psi on the oil system is going to play havoc with the crankshaft end seals, but at least on a Pinto the spray bar and valve train should be good !!
^ as unlikley as it might be its not impossible that you could have 2 doggy pumps (or gauges for that matter)
maybe you could borrow another known working pump/gauge rule things out completely - where abouts in the world are you ?
Hi
If it’s not the pump s or gauges or oil filters what could it be only a blocked pipe / gallery you have said the cam pipe is ok but is it clear and
not blocked where it pushes into the block can you see oil coming up to the top and spraying oil on the tappers
I think we are grasping at straws on this one
Graham
Is the oil filter fitted on the engine block as standard or are you using a remote filter/take off?. Is the oil pressure gauge fitted into the engine block / T piece on the oil pressure switch?.
This is why fitting an oil pressure warning light is better than a gauge. It prevents over analysing everything. The light goes out, it runs, f£ck it...just drive the car.
Think about it like this -
The oil pressure is meant to be ~45-65 PSI depending on the PRV in the pump (ignoring the 75-80 PSI HP ones burtons offer)
Some things like cold oil, blocked filters/galleries, wrong oil - could all have an effect of raising the pressure - but none of them can take it
past what the pressure relief valve will allow (at least not by much or for long)
If the pressure builds through the system for any reason the PRV should open limiting it
Even if you could somehow have a pocket of high pressure oil somewhere on the engine (stuck behind some kind of one way valve) it can't ever be
higher than the PRV will allow - oil isn't going to flow from a low pressure area into a high pressure area
all this really only leaves 2 options - either the PRV isn't working correctly for some reason (set too high, stuck or the outlet blocked /
partially blocked)
or the gauges are reading incorrectly
short of you having a second secret oil pump somewhere in the engine - there really isn't anywhere else this can be coming from...
[Edited on 16/4/2021 by mcerd1]
Exactly
Exactly what I said in my first post but maybe not so well described
quote:
Originally posted by Mr Whippy
This is why fitting an oil pressure warning light is better than a gauge. It prevents over analysing everything. The light goes out, it runs, f£ck it...just drive the car.
Have you changed the oil pressure sender (not the gauge)? It’s not explicitly stated in your OP although in a later reply on the thread where someone
has mentioned gauge and sender you said it’s been done.
As others have posted, it seems there are limited potential culprits for the high reading (and they’ve all been listed) and, inevitably, it must be
one of them that’s causing it.
I’ve read all the posts and don’t want to go over all that’s been said before but just add my thinking.
Oil pressure is created by resistance to flow but there are many places oil squeezes out of bearings and oil feeds but mostly the main bearings crest
the main resistance to oil flow hence why it is an indicator of bearing health.
If it’s a 1 wire sensor it will earth through the block make sure there is a few clean threads to connect the electrical path to the block. PTFE tape
is sometimes used and can insulate the gauge signal. A good earth is needed under the dash where all gauges should be earthed at one point.
A good engine block earth is needed as sensor measure resistance, a broken gauge wire throws the gauge to max end of the scale so maybe it’s a
resistance issue.
I would consider running a temporary earth to the battery from the sender and all new wires to the gauge from the sender, maybe pop the gauge out of
the dash and wire it direct to sender and battery.
Oil pressure senders have a perforated plug that lets oil through to the pressure sensor if this is full of crud MAYBE it’s not letting oil pressure
out just building pressure. Check sender unit perhaps swap with someone else to try in their engine.
I have no other ideas on this but please please let us know if you solve the problem.
quote:
Originally posted by bumpy
Before being put into storage at the end of last Summer my car ran with normal oil pressures, generally about 50 psi when running hot.
For some unknown reason it now wants to run at 90 psi most of the time. Its like someone turned on a switch to just about double the pressure!!
I put in a new oil pump, two new filters, changed the oil from 20/50 to 10/30, tried two other oil gauges including a calibrated capillary gauge and took the head off to ensure no blockages to all accessible oil galleries.
Looks like I now need the experts. Please help.
Is it possible to pressurise the oil if a piston ring is passing?
Although isn't the crankcase breather meant to deal with this? What if that was blocked?
[Edited on 19/4/21 by Toys2]
quote:
Originally posted by Toys2
Is it possible to pressurise the oil if a piston ring is passing?
Although isn't the crankcase breather meant to deal with this? What if that was blocked?
[Edited on 19/4/21 by Toys2]
if not quite literally explode 
Bump any news on the problem
Graham
Any news on what caused the high pressure ?
It’s always interesting to know for future reference
Graham
Seems the pressure is to high on Bumpy