Hey Guys, so i got my oil changed and the oil light is still saying there is low oil, does any one know how to reset the oil pressure light?

 

Hi csperling,

A very common issue with XJ40s is the oil pressure sender, which mounts on the left side of the engine block under the intake manifold. The original senders were of the "transducer" type, with a variable output that would allow the needle in the gauge to rise and fall with the oil pressure, but Jaguar found that their customers were being unnecessarily alarmed by the needle falling low on the gauge. Their solution was to replace the transducer senders with switch type senders that send a steady signal to the gauge to center the needle at all times unless the pressure falls below a preset threshold, at which time the orange "Aladdin's Lamp" illuminates (that's my silly term for Jaguar's depiction of an old style oil can). The light can't be reset: it's a real-time indicator with no stored memory. The lamp only extinguishes when the signal from the sender indicates the oil pressure is above the warning threshold. The problem isn't the actual oil pressure, it's the incorrect signal from the sender.

If your oil pressure sender is original to your car, it is probably no longer functioning properly. You can try cleaning its electrical connector, which may be loose and/or contaminated with oil. Changing it is far easier to do with the intake manifold disconnected from the head, but it is possible to do it "blind" by disconnecting only the air intake plumbing up to the throttle body and using a crow's foot wrench to remove the old sender and install the new one.

All that to say, modern low-viscosity oils seem to cause the dash warning lamp to illuminate more often, (especially when idling with the transmission in Drive). If you're running, for example, 10W-40 oil in the summer instead of 20W-50, you'll probably get the warning lamp more often.

On the Jag-Lovers forum a number of veterans had a discussion about whether any of us had ever heard of an AJ6 engine failing due to low oil pressure, and none of us could recall ever hearing of one, so you're engine is probably not at risk. But I know how irritating the lamp is.

Replacing the sender may help, or it may not. Many of us just keep the oil topped up with the proper viscosity oil (as recommended by Jaguar) and live with the sender's idosyncrasies.

Cheers,

Don

 

Don, sorry to resurrect an old thread here, but I was wondering: Is there a new 'design' oil pressure sender that is available as a replacement? My wife wants to drive the Jag in the future and I'm trying not to train the 'don't worry about the oil pressure' behavior


Thanks,
Pete

 

Did you change the oil yourself?

A few years ago, I made the mistake of having it done for me and I had low pressure reading. The shop did two things.

One, they used the wrong viscosity, I always run 20-50.

Two, they "assumed" the quantity to replenish, they were wrong.

If you're confident the above items are okay, then check the sending unit.

 

I have to double check, but I think I'm running 10w40 based on being in a colder climate...(at least heading into it, for another 5 months)... I know the level is ok, as I just checked the level...and nothing's leaking or burning, miraculously...


Pete