Oil Pressure

[Taff]

Hi All,

Just replaced the oil gauge and sender with a JEC in my 69 Series 2.
The oil pressure was very low, 5-10 cold. Now its gone the other way, showing oil pressure off the clock at 65 lbs. Took it for a 10 mile run to get the oil up to Temp, and its still off the clock.

Just wondering if anybody here has ever had the same problem,

Regards,

Art

[JEP41]

Hi Art,

I had a lot of trouble with oil pressure readings on both my E-Type and MK2. Like yourself I tried different senders, each one tried seem to give a different reading so I purchased direct pressure gauges from MC Wilkinson these are calibrated to 100 psig and after firstly checking the calibration of the gauges, installed in my cars. With these gauges installed there is no doubt what the pressure is, good or bad

[Heuer]

Agree with John. I fitted the JEC gauge and the needle was pegged to the stop so I installed M&C Wilkinson mechanical 100psi gauge which shows the pressure at 68psi, correct for my VSE02 engine.

Even with the JEC gauge your pressure should drop at idle when warm. Could be a dodgy sender or the wiring is wrong.

[hedde]

Hi Art,
I have the same problem. Installed the JEC sender gauge combination. With engine off I am reading 40, it goes up to 60 with running engine.
I measured the sender, engine off -> 285Ohm, engine running (cold) 130Ohm.
Maybe the gauge should be conected to the voltage regulator that delivers 10V instead of 12V? Just guessing, the diagram states otherwise.
Thanks for any reactions.
Hedde

[daverawle]

Hi Art,
I have the same problem. Installed the JEC sender gauge combination. With engine off I am reading 40, it goes up to 60 with running engine.
I measured the sender, engine off -> 285Ohm, engine running (cold) 130Ohm.
Maybe the gauge should be conected to the voltage regulator that delivers 10V instead of 12V? Just guessing, the diagram states otherwise.
Thanks for any reactions.
Hedde

If you get any reading on the JEC gauge with the engine stopped there's a problem, either with the wiring or the gauge; it doesn't need a regulated supply.

I just edited this... I don't understand why a 60lb gauge would peg, that's the whole point of the pressure relief valve.

Dave

[hedde]

Thanks for your reaction dave. I can't think of anything wrong with the wiring, battery plus to gauge to sender. I checked the polarity on the gauge and can't imagine it will work the way I described with the polarity wrong.

Are there any checks to prove the sender or the gauge is wrong? I am looking for a table with Ohm - LBS relations.

Regards,
Hedde[/quote]

[Heuer]

... I don't understand why a 60lb gauge would peg, that's the whole point of the pressure relief valve.

Dave

In my case it was because the oil pressure relief valve blow-off pressure was 75-82 lbs. Idle pressure 52 and at 3,000 rpm 75lbs. All this data from the VSE Hot Test Report on my VSE02 engine:


Hence I bought a 100psi mechanical gauge.

[Taff]

Thanks all, for your replies.

A little delayed in doing so, has its taking some time to get the info needed.

Having spoken to JEC, and a very nice person running it I must say, it was decided it would be best to go to the premises and have a chat with the Design Engineer Ian John.

Explained to Ian my problem with the readings from gauge. Came up with a table of numbers to do a test on the sender unit. They are as follows,
0% 250 ohms
20% 225
50% 129
80% 57
100% 20

Test: Engine off. Remove wire from sender Terminal.

Measure resistance from sender terminal to block, should be more than 250 ohms.

Engine on, still wire off, measure resistance again, should be one of the figs above.

Having tested my own, i was having 14.6 with engine on. Needs to be over 20 ohms.

Having spoken to Annie at JEC, I have had the sender replaced.

Repaced sender today, and its still the SAME...

Check power supple, Earth, and even used another cable to sender, all good.

Will be returning to Caerbont Automotive Instruments with the Gauge and sender to be Tested by them. The story will continue tomorrow...

Art

[christopher storey]

Taff : with that reference to Caerbont, have you been mixing a Caerbont ( ie standard) gauge with a JEC sender, because AFAIK the two are incompatible - the JEC sender must be matched with a JEC gauge

[hedde]

My problem is solved. It was an not in place earth connection on the gauge.

Art, did you ground your meter/gauge correct? I got the same results as you had, but an good earth to the gauge solved my problem.

Keep us informed.
Regards,
Hedde

[Taff]

Hi All,

It looks like we are back to square one. Called to see Ian John at Caerbont this morning where he tested the gauge and sender there in front of me.
All working as they should be. So many Thanks to him for taking the time to do this for me.

That still leaves me with the same problem.

Will now fit a Mechanical Gauge to find the true pressure, and then decide from there on which one to use. Can anybody point me to the best place to buy a T Piece Adaptor and the necessary pipes to do this. Would it be better to use a Steel Adaptor or use Brass?

Hoping to pick up a Gauge tomorrow.

Thanks again for all your replies,

Art

[daverawle]

Taff,

We should discount your old gauge as they were unreliable and didn?t improve with age. So, re-reading your posts: the JEC gauge is pegged both cold and hot; the gauge has been tested by the manufacturer and proves to be accurate. No need then to go to the trouble of lashing up a mechanical gauge which will show the same thing. For your own satisfaction you could attach an air-line to the sender and see if the reading matches the air pressure.

Has the system been modified in any way. Spin on filter, oil cooler, different filter head with the wrong gasket?

Dave

[Taff]

Hi Dave,

Having gone through the trouble to get this far, I would still want to know the true reading with my oil pressure.

As for the system being modified, it all looks original as far as I can see.

Been around a few local places today looking for a T piece, not having much luck..

Will keep looking over the Weekend,

Art

[Heuer]

Art

Try a Plumbers merchant (they are BSP fittings) or a supplier who deals with hydraulic or air lines. Failing that give M&C Wilkinson a call as they supply a full Mechanical gauge kit (?130 I think) so will have the ancillary parts off the shelf.

[Taff]

Hi All,

Managed to find the T-piece, plastic connecting pipe, and Adapor at a place called Speedy Cables. Here's the Link should should you go the same route. http://www.speedycables.com/

Another I found is, http://www.merlinmotorsport.co.uk/INSTR ... index.html

Found the Oil Gauge at the Newport Classic show over the Weekend, costing just ?8. There are also quite a few being sold on bay.

Finally I have a true reading of my oil pressure. 70-75 from cold. Dropping down to around 65 when warm. Now I know why the JEC gauge was pegged to the 60.

My only concern now is can you have too much pressure?

Also, which gauge do I keep. I may have a JEC gauge kit to sell.

Art

[pmansson]

My S1 3.8 has a different gauge, going all the way to 100.
Was probably installed in Germany along with an oil cooler (no longer in place).
Is this part of the JEC mechanical kit?
I haven?t looked for the sender.
What can I expect to see?
Normal position, or mounted somewhere else?
Thanks,
Peder

[Taff]

Hi, If it is a JEC, you will have Elec wire running to the sender on the
oil pump, like you would on the original set up.

Hope this helps you,

Art

[Heuer]

Peder

There are some pictures here: http://etypeuk.com/forum/viewtopic.php?t=173

The 100psi gauge is likely to be a mechanical one.