After 800 miles of flawless operation on my Monterey Car Week road trip, I backed it into my parent's garage last night when the oil pressure gauge suddenly dropped to zero. I immediately shut the engine down to check the oil level, which was completely normal. After starting the car again, I noticed the gauge go up to normal, fluctuate for a few seconds, and then drop back to zero. Considering that, I believe it is just the sensor beginning to go bad. I couldn't find any definitive answer or diagrams online last night but after following the oiling pipes, I guessed that it might be the sensor at the top of the engine in the back of the V with a single yellow wire coming off of it. After fiddling with the connection for a bit and restarting the car, the oil pressure gauge and light operated completely normal.

A couple of questions:

1. Is this the right location of the sensor?
2. I notice that the replacement sensors appear to have a resistor pack ( ), My car dosen't appear to have this, would this be the correct part for replacement?

 

Jaguar addressed this issue several decades ago.
I would not reconfigure the INSTPK but the switch will turn the gauge into an 'idiot-light' if you still have a pressure SENDER/SENSOR instead of a switch.

 

Well, I think the original sender/sensor is on the fritz and the old-style one no longer appears to be available. It didn't really fluctuate anyway before this so turning it into an idiot light/gauge isn't that bothersome. I just want to make sure that thats the right sensor I'm looking at and if thats the correct replacement part.

 

You've got the right location, LNA5642CA is the right part (the switch). There is some doubt if the Amz JLM part will fit. I've heard the replacement LNA part has a resistor attached to give the correct output, the original transducer doesn't have one.

Great to hear of your total success at Monterey car week! I was imagining the fun that must be. I hope you rolled into town with your Union Jack skull cap on, proud as a new daddy to be behind the wheel of the Monarch of luxury automobiles!

 

Ok I'm on track with you, LNA5642CA looks to be discontinued, and it was the TSB switch replacement part. But I see JLM20791 fits as the replacement for the replacement. Worth a try I'd say, can't go around looking like you've got no oil pressure! (Ref: Terry's and Jagbits)