4.0 Oil Pressure Sensors - Which Type Do You Prefer?

Been thinking of getting Superblue a new oil pressure sensor to help “celebrate” her recent 100,000 M “versary”. :smiley: Lately it seems more and more often her gauge reads on the low or even very low side (but no red light) although the oil level is fine. This is esp. true when the weather outside is hot and/or she had been running a long time w/o shutdown. :grimacing:

As we know, the OEM-style sensor that transmits the actual pressure readings was later “upgraded” to more of an “idiot light”-type sensor that continuously reads midway on the gauge so long as there is “some” oil pressure in the system. This upgrade by Jaguar was due to a “high failure rate” of the OEM sensors.

Wondering which type you have/prefer in your 4.0 cat? :confused:

Myself, I would tend to lean toward replacing her OEM style sender with another OEM one, being a bit of a “purist” as well as wanting to know the actual reading of the pressure. :thinking: However, I have found it interesting that the OEM-style sensors are relatively rare anymore when it comes to vendors, and I even checked a few of the usual suspects (i.e. sellers of only Jag parts) and was surprised to find the upgraded version of the sender is the ONLY version they sell. :open_mouth: So, that fact alone makes me think that the great majority of XJS owners must prefer, or at least are happy with, that version. Also, and I don’t know whether this plays a part in that “inventory decision”, but the OEM-style sensors that are still out there typically sell for 3x as much $$ as the upgraded version, or even more. :open_mouth:

Yeah, I find the old original style rare and over-priced. I’m not even convinced that the old style will actually be the old style when the part is received…as everyone knows, a common point of disappointment when ordering replacement parts for these cars.

I don’t need to spend that much more for peripheral information, especially since it’s a part that will eventually fail again and need to be replaced.

I stuck with the standard dummy sensor. No sense in overthinking this one. Either you’re comfortable paying the price for an interactive gauge, or it’s not worth it.

There are plenty of pressure sensors showing actual reading. Naturally non-OEM. You can easily find them on eBay. You will notice difference straight away.

Another thing to clarify: what makes you think that OEM means “quality”? It’s a stereotype, same as the people thinking that high price means good quality…

I consistently have significantly less problems with OEM, especially rubber.

Does that mean I buy anything at the dealer, hell no, but if I have to gamble with my money and/or my time, OEM will always be the safer bet.

In this case, specifically, I would go through an oil pressure sensor from URO every 10-15,000 miles. One time I had my shop call out the leaking sensor at a safety inspection, I had him replace it and I haven’t had a problem since. (They apparently used the part from Jaguar?)

I have a Sun pro after market sensor and guage.
Got it when my original arrangment was suspect. I wanted a mechanical guage to get a real verification. Not found.

I plumbed it in. In lieu of the Jaguar unit. Teh Sun pro had two connectors. So, one caused the guage to read as it should in PSI numbers… the other, not so.

Much better quality, but larger!!!

I got an original NOS from David Boger of everydayxj. All is well, numbers are what they oughta be

Aye, I prefer the real time units. The stablized units are to allay the fears of some tht happen when the needle moves!!!

My JEEP has the “no fear” type. Once tempted to fix that. No longer, I just live with it


I think you can break replacement parts down into three categories: OEM, cheaper than OEM, and better than OEM. The aftermarket being what it is, a lot of the non-OEM items fall into the cheaper than OEM category. For Jaguar parts it’s not all that common to find parts that are better than OEM, although it’s very common for GM or Ford parts.

On very rare occasions you can find non-OEM parts that are both cheaper and better than OEM. The poly steering rack mounts and the heater valve come to mind.

I’m glad you think that way…
Unfortunately - quality of OEM parts ends when car models falls off the manufacturing line.
Believe it or not, after this - batches of replacement parts are entirely uncontrolled.
Manufacturers are asking their suppliers to deliver small batches of parts when running low on stock. There is no SPC, no PPAP, no frozen processes as the suppliers would never accept small orders of such for the contracted price. Long lead time for each orderbis another thing.
There are only two requirements:

  1. Part must fit
  2. Part must work

Maybe hard to believe, but true. I cannot recall XJS being still hammered in Coventry…

Obviously you haven’t been following the thread about the guy trying to replace the heater core in his Delanair MkII.

I couldn’t, I was in the nursery that time and the topic was ongoing until end of my primary school… Frankly, done that myself later on. How old are you huys anyway…

ME ! 91 going on 92 I hope!!!


O.K., my new one came in today, and I decided to go with the upgraded version of the sender. I’m curious to see whether my '94 lug wrench for Superblue perfectly fits it, like the one in my '95 (Supercat) did. If so, should be EZ-PZ to reach down there from above and knock the old one loose, start the new one in and tighten with the lug wrench. :joy:

One thing I’m wondering, since I have never r/red one of those senders before on one of my facelifts, is when I break the old one loose is a ton of oil going to come gushing out all over everything through the sensor hole? :grimacing:

I think that can happen and does happen, but doesn’t necessarily happen. For a long time I could get Jaguar-branded/boxed parts that were indeed exactly what what used on the assembly line. Or they at very least had all the same markings and identifiers. My last few experiences have shown that Jaguar has turned to other suppliers and I’m pretty sure I’m getting the exact same brand-x parts as I would get from any number of aftermarket suppliers.

A few years ago I was researching parts suppliers and I recall reading something to the effect that Jaguar (and some others) had turned over a lot of its replacement parts sourcing and distribution to outside entities such as URO and Eurospare.

Every car manufacturer naturally monitors supply and demand of replacement parts and negotiates contracts to have them made. If a contractor is no longer interested in supplying the part (or is no longer in business!) then a new supplier is sought out and negotiation begins anew. And, judging from my experiences, Jaguar has lowered the quality control requirements quite a bit.

It’s fun and popular to grouse about Jaguar quality but, really, a lot of the parts they used once-upon-a-time were high grade items.


For oil pressure I really don’t care. I can’t even remember the last time I heard of a Jaguar engine suffering from an oiling system failure.

Temperature gauge? Well, I’d rather have a true-reading type.

My X300/XJR had dummy gauges for both. Bothered me at first but soon forgotten.

FTR, Jaguar is not alone on dummy gauges. When they finally threw-in the towel and joined the ranks of others I’m sure dealership service personnel were relieved. No more fretting customers calling whenever the needle moved off center!


Now you have me worried, DoubleD :grimacing: … are you saying our (facelift) temp gauges are “dummy” too? :open_mouth:

Not sure about the XJS. But on the X300s they went to a dummy oil gauge in early '95 and the temp gauges were the dummy style from day one (or maybe I have that backwards?)