Hi again,
My 1976 XJ6C 4.2 is having oil pressure gauge problems.

My oil pressure, per the dash gauge, rises from zero to about 20 psi very slowly after startup. Takes 3 or 4 seconds. Then goes to almost 40 lbs when raising RPM to about 2500. Never goes higher. After running to temperature it drops to 20 lbs at 2500 RPM and below 20 lbs idling. I hooked up a mechanical gauge and get 62 lbs cold at idle rising to 75 lbs at 3000 RPM. Never goes higher. At temperature it drops to just above 40 lbs at 3000 RPM and just below 40 lbs at idle. I replaced the oil pressure sender with C46272 from URO. This made no difference. I believe its the correct sender. So I'm guessing it is the gauge. I ordered a NOS gauge and am waiting for it....

While waiting, I looked at the wiring diagram in my repair operations manual (published by british leyland in 1988) and noticed that the oil pressure gauge is NOT fed by the Voltage Stabilizer, Yet my gauge is acting as though it is... 3 or 4 second delay in the reading... Any one else see this delay behavior on their oil pressure gauge? Or do you see pressure immediately?

Thanks,

Steve

 

That gauge will never be accurate, no matter what you do. Better off just making sure it keeps doing what its doing. If its not moving, you have a problem

 

Hi Steve, I am using a standard Jaguar sender and the original gauge in my '85 S3. My gauge reacts immediately at startup and with RPM change, but the other three gauges are quite slow to settle on the correct reading. I have checked my pressure with a mechanical gauge and find the stock unit completely accurate.

Dave

 

Dave,

Thats what I would expect after reviewing the schematic. It shows the Voltage Stabilizer, which is basically a big capacitor, feeding all the gauges except the oil pressure gauge. However, mine ('76 S2) acts as though all 4 gauges are wired to the stabilizer.... If I can get the damn speedo out, I'll trace the wiring to see if it agrees with the schematic.... maybe a previous owner mis-wired it? Very strange...

Thanks,

Steve

 

Do your speedo and tach come out like an S3? Push in and turn counter clockwise 1/2", pull straight out.

Dave

 

Dave,

My tach removes easily... the speedo is ridiculously hard to remove... I'm 6'4 -- 200 pounds working with my hands all my life... but cant push it in far enough to get it to twist.. bottom pushes in fairly easily... top is stubborn... like something behind obstructing it... I'll give it another try this morning.

Thanks

Steve

 

get one of these for the toolbox..... 2.5 inch suction cup from harbor freight..... $3.... push and twist left.. literally 2 seconds... tried pushing and twisting using my fingers for about 1/2 an hour last night without any luck.

thanks,

Steve

 

n No worry. You have OP. the tme to worry is when tere is none.

those numbers and actions slund just fine to me.\\A rule to guide one i ten punds per thousand RPM.

M lum rns at a much lower OP. designed that way\\OP not as imprtant as ol flow. teh latter not subject to measure.

Carl

 

Caution on the suction cup, the speedometer face is most likely plastic. I suggest getting a cheap pair of rubber palmed gloves (Lowe's has them in the paint dept.) Then remove the lower dash panel (over your knees). Then with one hand grasp the front of the gauge and with the other reach under and grasp the back of the gauge. Then you will have enough torque to get it out.

Jeff

 

I have a '75 SJ6C and all my gauges are glass.

 

Yes, my '79 has glass on the speedometer but my '87 has plastic. If the odometer reset knob is through the speedometer cover it's probably plastic.

 

Hi again,

So i finally got my NOS oil pressure gauge... and no difference.... gauge sweeps to just under 40 lbs when cold and drops to about 20 when warm... with the gauge sitting on the inner fender (insulated with a rag) I completely isolated the new gauge and sender by wiring them directly, taking it out of the wiring harness.... So maybe i have the wrong sender or gauge? the gauge is a SMITHs 2212/00 and the sender is jaguar part no C46272.

Very frustrating.

Thanks,

Steve

 

Steve,
The sender you purchased (C46272) is the exact part number I ordered from Summit Racing and it works fine. I don't know if I have Smith gauges though.
Take a look at this chart I found on the interweb. The 0-80psi Oil Pressure chart (American) is how mine reads. Look at the resistance for pressures and see if yours corresponds.

Dave

.

 

I think I may have found the problem. I saw this on the Moss Jaguar site buried down in the "where used" tab.
Checked my VIN and looks like i need C31177... Ordered it.... we'll see...

Thanks,

Steve

 

Of course, the one you need is twice the price!

Dave

 

In one of my lump adventures, I sought a mechanical guage to verify the OP. No luck. i settled fpr a sun Pro electric guage and sender. i plumbed it in. it verifies that my lump OP was just fine. and then just for kicks i connected the Sun pro Sensr to the jaguar guage. it rae d the same. Whee, the sun pro sensor was more robust. But, i went back to a NPs sensor. Sourced from ever reliable david boger. everydayXJ.

 

Dave,

Yes twice the price..... it seems the C46272 is an industry standard... get them any where... so they're inexpensive... on the other hand, C31177 is peculiar to british cars and pretty rare... cheapest I found was $80.. saw some for $150. Love my Jaguar!

Thanks,

Steve

 

According to my records, I paid $23 for the C46272 from Summit. After some of the other Jaguar parts I've bought, I'll take a bargain.

Dave

 

So, I tried going the cheap route and got a sender the vendor thought was C31177.... It was in a box marked C31177 but the marking on the sender itself was a pt1802/00 which is wrong... I need PTR1811/10... So got one from Moss... $130 sender, tax, and postage... and everything works now.... YAYY!


Thanks Everyone for your help!

Steve

 

On the older cars ( E Type, Mark 2) there was two possible senders. One went to 60 psi, the other 100. Sounds like you had a 60 psi sender mated to a 100psi gauge.