Jump to content

Oil Pressure Gauge


Recommended Posts

Turn on ignition and before I start the engine the pressure gauge goes to max off the scale! Once started it stays right over pass max.

Is this as simple as a faulty gauge or could it be a problem with whatever is on the other end of the gauge?

Cheers in advance

Link to comment
Share on other sites

Thanks for replies

The two wires that connect to switch have got hot and fused together.

Don't know how I'm going to get to them without dropping the down pipe or possibly the manifold.

May leave it until they need to b removed.


Link to comment
Share on other sites

Short circuit. 12v will give full scale reading

Dude you are forgetting stuff.

Open circuit makes it read full scale, so disconnected at the plug on heater box, broken wire or broken sender. shorted to earth reads 0.

You can see I am right if you disconnet the twin plug on the wiring loom near where it is zip tied to the airbox, you will then have no oil light and oil gauge reading full scale showing open circuit reads high

Theres a plug for that part of the loom byup the bulkhed. Unplug it, squeeze your fingers up below the exhaust and the engine block (assiming its a CIH) pop the spades off and repair the little loom in your garage and reinstall.


One is a spade and other a ring terminal as standard so if not been messed with that doesn't quite work.

I have a spanner cut in half to remove them with manifold on.

Once you haveone removed DO NOT try to undo the nuts holding the terminals on.

The terminals have a square post in some form of insulator, trying to turn the nut twists them, often it shatters and they are then scrap.

Each terminsl post has flats on the tip, gripping these , so as not to damage thread, will sometimes allow the nut to be spun off so you can change the ring terminal.

Last time I had two senders so I converted mine to twin spade terminals by bolting the same "adapter" the other terminal has off a spare unit onto the other post.

Even when you have done all this you may be working with a broken sender.

Also on reassembly, as it works like this...................

OIL LIGHT Wire earther = light on

OIL LIGHT Open circuit = light off

OIL GAUGE Wire earthed = 0 bar

OIL GAUGE Open circuit = 5+ bar

If you get wires backwards when you have oil pressure you will have open circuit and 5+ bar on gauge, but on light you will have no light when no pressure and once started ranges of glowing light, drighter at idle and less bright when revving , this confuses people

If they are backwards on the sender once re-assembled do not dispair, they can be popped out of the connector where it connects to the car loom and swapped there.

Two SEPARATE heat proff sleeves, one for each wire, silicon maybe will avoid having to do this again

Some people move the sender to the oil pump priming pump up front to avoid replacements getting baked / having to reach the old one but this area is more prone to damage and might not give same reading as it's pressure in themain gallery that matters

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Create New...