It could be this, It might be that

[DoctorDee]

I wouldn't be on here asking silly questions AGAIN if the Title of this post was not relevant

One of these piccies is a oil pressure gauge....... The other is a sender

What a clever dickie I am !!!

The pressure gauge once lit up never reads less than 100 psi

The sender, I assume, operates the o/p gauge and a low  pressure light...

Either the high oil pressure reading is the result of a duff sender,(please Lord), or a stuck oil pressure relief valve.

On a Zetec 2 litre that means sump off,  etc.etc..... Hallo Mr Ford parts man,  here's an engine no, ......"Need a chassis/ reg no mate" etc, etc

Any road up.

As the gauge is one of those  flashing light thingies and not a wavy pointy needle thing....

Does this mean that all the senders that am on ye olde evilbay are about as much use as the proverbial chocolate fire guard.

As usual, any advice will be gratefully received

 

 

 

 

 

 

[Peter Bell]

Did the gauge and sender come together? They will need to be matched. Oil pressure light will have its own switch/sender.

[IanS]

From the bottom picture Oil pressure light has its own switch at the end of the adaptor with the guage sender screwed into the side.

Out of curiosity what happens when we know that there is no oil pressure? Unscrew the sender and remove the PTFE tape to make certain that there is no trapped pressure and see what the guage reads.

Second thought is regarding the PTFE tape, does this system require an earth through the body of the sender and is the tape preventing that, test by connecting a wire from the body of the sender back to the battery negative.

[Snapperpaul]

Gauges measure differential resistance, they usually only have 1 wire to the sender, if the sender wire is broken or the sender does not Earth through the block the gauge will read maximum.

often to much PTFE will block the sender earth, I only wrap half of the thread in PTFE.

If you have a T piece or double output adaptor that takes the sender and the warning light switch you’ll probably have PTFE on that as well.

you could try a crocodile clip on the pressure sender body and earth that to check

[geordie40]

+1 for removing the ptfe tape from sender and adaptor, most senders earth through the body of the sender 

[nelmo]

1 hour ago, Snapperpaul said:

Gauges measure differential resistance, they usually only have 1 wire to the sender, if the sender wire is broken or the sender does not Earth through the block the gauge will read maximum.

I had the same thing and it was my wire from the sender that must have been broken somewhere (it was buried in the depths of my loom) - I just threaded a new wire from sender to gauge and worked fine (I wasn't using PTFE tape).

But it may never work if the sender and gauge didn't come together - they need to be calibrated for each other.

[Longboarder]

How many terminals are there on the sender? For example mine has three. One to the gauge, an earth and one to the oil warning light. Some senders have a built in low oil pressure warning light as well as the sender for the gauge.

Edited March 28, 2019 by Longboarder

[DoctorDee]

Thank you gentlemen..

As always, your replies are informative, concise and most importantly  make sense to a village idiot...IE me

The gauge functioned when I picked up the vehicle.......At some point it has ceased to operate

It's positioned on the nearside of the vehicle.... It's not visible from the drivers seat.... Nuts isn't it

Looking at the photograph of the sender you can see that there is shed loads of PTFE tape around the threads....

I will get out me length of wire with crocodile clip soldered on to it...

Report back I will... there may be a delay as I am rebuilding the front suspension and brakes at the moment

There is so much that is cockeyed with this thing I am seriously kicking myself. I paid way over the odds for it..

Thanks again

 

 

 

[blue]

Can I just add the zetec runs very high oil pressure - tick over is normally around 8 bar cold which is just over 116psi  -your gauge only reads to 100 psi food for thought 

Edited March 28, 2019 by blue

[DoctorDee]

Nothing surprises me with this car....absolutely nothing

[Longboarder]

I believe the pressure relief valve lifts at around 5.5 bar setting the upper limit hot or cold. Haynes quote hot 3.7 to 5.5bar at 4000rpm. Lower above that due to the piston cooling jets opening. My gauge only shows 4bar at 4000rpm hot.

I think you still don't have a complete electrical circuit running your gauge. No idea where the break is.

[DoctorDee]

Once again, many thanks for your assistance