See the three threads below, that essentially all detail how in circa 1995 Jaguar went to an "idiot/dummy" oil pressure sending switch versus sensor for our oil pressure gauges that causes the gauge to be somewhat binary instead of showing actual pressure.

https://www.jaguarforums.com/forum/x...e-gauge-41482/

https://www.jaguarforums.com/forum/x...e-gauge-11432/

https://www.jaguarforums.com/forum/x...r-moves-36676/


So with the information above in mind, I wonder if any one has found a traditional and reliable sensor/sender that will install in place of the OEM sender with no modification that will return the gauge to a true analog function showing true pressure as it rises/falls?


Similarly, the water temp gauge apparently suffers a similar fate where it only registers ranges of temps. It has its own sender, so I wonder if that function is in the sender or gauge pack itself. It would be nice if it showed actual temperature as it trended in real time.


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The instrument cluster gauges on the X300 are stepper motors, not conventional analog gauges. They are controlled by a computer in the instrument cluster module, and it is this computer that determines how the gauge behaves.

As some of you know, I make 'RealGauge' for the X308 and X100 Jaguars (XK8 / XKR / XJ RealGauge - TheJagWrangler ). Unfortunately, the X300 has a different instrument cluster design, a different coolant signal type and a different oil pressure switch, so RealGauge is not compatible with the X300. Despite this, I believe it is similar enough so that RealGauge can be adapted to work with the X300 with some software changes, a different mounting scheme and a different oil pressure adapter.

I would be willing to consider doing this over the course of the next 12-18 months if at least ten X300 owners come forward and state they are willing to buy this product (it sells for about $280 for a coolant and oil pressure conversion) and one owner in the metropolitan Washington DC area is willing to let me have access to his vehicle for installation, testing and documentation over a period of 2 to 4 half-day sessions. The owner who donates his vehicle to this development would get the upgrade for free.

The decision to develop most of my products has been driven by popular demand on this forum and this one would be no different.

 

Too bad I'm not in the D.C. area

Thanks for making the offer, and it will be interesting to see how much interest this develops. It would be great if there were enough interest to get this designed and developed.

I think $280 is a fair price, but that may be too pricey for my budget in the near future given some other pressing issues I've got to address on the XJR, other cars and house ....so I can't personally commit at this time unfortunately.

But I'll keep an eye on how many get on board, and if the product gets developed, perhaps can pick one up later.

Thanks again, this is a great and unexpected reply

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I was put off by the dummy gauges as well...but I eventually adjusted and even become fond of blissful ignorance. Overheating is a very rare occurrence and oiling system problems are virtually unheard of. With the AJ16 engine a gauge conversion like a cure looking for a disease

I'll admit it would be sorta neat, though.

Cheers
DD

 

I just use an ultragauge to monitor coolant temp. Bought it solely for that reason. But a working gauge would be nice. I would be willing to pick a realgauge should one be available. Would have jumped on the opportunity to be the test subject if I was close to DC

 

I hear ya, but like a lot of inexplicable things... to me, gauges that actually move add to the living/breathing element of the car & driver

....not really limited to cars either. I like blinky lights, gauges, meters and machines that go "bing"

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Steve, much as I appreciate the Realgauge in my xk8, I am comfortable using the Ultrgauge in my X300. That engine is so reliable that only a major coolant leak is a risk, and over the years the causes and prevention have been pretty well documented.
That said, there is no question I would purchase Your Realgauge x300 combination. I grew up (debatable) in the age of analog functioning gauges. My Alfa's even had oil temp, and I am most happy when I see real numbers in the acceptable range.

 

For you, Al:

ACHTUNG!
ALLES TURISTEN UND NONTEKNISCHEN LOOKENPEEPERS!DAS HELIOKOPTERMASCHINE IST NICHT FÜR DER GEFINGERPOKEN UND MITTENGRABEN!
ODERWISE IST EASY TO SCHNAPPEN DER SPRINGENWERK, BLOWENFUSEN UND POPPENCORKEN MIT SPITZENSPARKSEN.
DER MASCHINE IST DIGGEN BEI EXPERTEN ONLY!IST NICHT FÜR GEWERKEN BEI DUMMKOPFEN.
DER RUBBERNECKEN SIGHTSEEREN KEEPEN DAS COTTONPICKEN HÄNDER IN DAS POCKETS MUSS.

ZO..... RELAXEN UND WATSCHEN DER BLINKENLICHTEN.

Steve,

Great offer, but like Doug, I've come to appreciate the binary performance of the X300 Inst pack, along with the reliability of the AJ16. When I am overcome by a hankering for the real numbers, I consult my phone/Torque/ELM327 adapter system for a look-see.

 

Curious, with the AJ16 holding such a large 8.5 quart oil capacity, how much oil can be lost before the "dummy" pressure gauge and warning lamp will indicate a no/low pressure situation?

Also, is that gauge/lamp a conservative indicator (i.e. indicates far earlier than damage or concern would normally occur) or like some "idiot lights" only indicate when it is too late?

I guess a related question might be what is the actual minimum capacity oil the AJ16 will run and maintain pressure without damage?


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When I first learned that the oil and water gauges were dummies, I did feel a bit let down, but when I later had the rationale explained to me, I did manage a smile.
Customer research had identified that many customers (and more importantly, prospective customers) equated steady gauge readings, in the middle of the scale, with reliability, an area where Jaguar had considerable room for improvement in those days. Members of this forum are a self selecting minority among the wider Jaguar owning community, and our interest in and understanding of fluctuating gauge readings would not be widely shared. The majority prefer middle of the scale unless there is something amiss, and prefer a warning light when something goes awry to the extent of needing an intervention. Jaguar (Ford more likely) were simply paying closer attention to what customers wanted. In fairness, it should be acknowledged that they had built an engine whose reliability was such that the oil and water gauges had never been less relevant.
Turning to the question of whether those of us who are more technically minded should be thinking of making our gauges "real", I still think the answer is far from clear cut.
The "dummy" water temperature gauge shows the temperature building from cold, and moves quickly to the red if the temperature should stray above normal. When my water pump/ alternator drive belt broke, the gauge moved quickly enough to red to persuade me to stop, where the no charge warning light made me think of driving on to see how far I could get before the battery dies. Net result, belt replaced, water topped up, no further issue.
Combined with the low coolant level light, do we not have all of the information about our engine cooling that we could need? Do we want to have the forum pages full of threads about " my water temperature gauge moved 5 degrees today, what should I do?", and a raft of replies about the battery, the alternator, the sender, earth connections,the instrument pack, not to mention the coil pack, before we get to those that concern coolant! We are blessed with cars which are rarely afflicted in this area, and if it aint broke....
The case regarding the oil pressure sender is perhaps a little different, although it is again worth reminding ourselves of our good fortune with the AJ16 in this area.
Thanks to good engineering, and modern lubricants, the general body of evidence would suggest that these engines are good for +250,000 miles in rude health, and without any significant mechanical interventions. Consequently, one of the historical uses of oil pressure as a barometer of general engine health, is of little current relevance. As a means to detect some catastrophic oil loss event, such as a punctured sump, or the more common, low sump contents, an oil pressure gauge tends to be at best a "lag" indicator, as it is only after the oil pump starts to ingest air that you receive an indication of a problem, and by then your problem is well under way. In any event, the drop off in pressure would likely be so marked that the low oil pressure light would pick it up just as quickly as a "real" gauge.
As with the water temperature gauge, just thing of the fun we could have with threads in the forum about 5 psi drops in oil pressure!
For my own part, I am not minded to try to make my gauges "real". Combined with the warning lights, the "dummy" gauges tell me what I need to know, but of course, each to their own.
On the other hand, if someone had an upgrade to create a low oil level light......

 

For the record Jaguar is not alone in the 'dummy gauge' thing by any means. They've been around for years in various brands. And, even before the dummy gauges many were so heavily dampened that the reaction was *very* slow.

Yes, customers often get nervous whenever they see a needle move. When I was in the business I can't tell you how often customers' anxieties needed to be assuaged....which wasn't always easy. Sometimes it seemed as though they wanted there to be a problem and were convinced I was lying when telling them that oil pressure would drop at lower RPM or as the engine got hotter!

Cheers
DD

 

Would this new product work with my X305 1996 XJ12?

As many know, the V12 suffers from more cooling issues than the I6 and it would be very nice to have live gauges for oil pressure and temperature.

Thanks,
Nick

 

I performed MANY of these 'conversions' when the senders became faulty. We used both PDU and WDS to recalibrate the INST PK.

I don't know if the INST PK can be used with a variable sender once the calibration is completed.

alholbro1 and I had this discussion (along with others on this forum) some time ago and I don't remember if anyone installed an older sender in a re-calibrated INST PK.

You can do a search for this discussion we had a few years ago.

With a PDU or WDS you can read what version of software is installed in any given INST PK so a salvage yard cluster might NOT have been 'updated'.

You could install that unit and then a suitable sender???

Read the attached TSB.

bob gauff

 

BTW, does the oil pressure warning light also have an audible alarm, or just the light?

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I didn't know I knew German so well until now!

Thank you for that Mr. Holbro! Thanks are in order to White XKR too, for offering to develop a system. Great points made here. I too don't see a large enough demand with the X300.

Be it known that the early 1995 MY cars have "true" OIL pressure gauges... as does my 1995 XJ12. The gauge reads "0/4/8" (bar) instead of the "N" in the middle of the range like the 1996 XJ6. I have never seen a false low oil pressure reading on the "true" gauge nor any warning light. Edit: Now I'm wondering if my car got the upgrade without my knowledge!

Knowing that the COOLANT gauges are not true, I watch for the low coolant light, especially in the XJ12. That light will come on almost immediately if the coolant level drops much. STOP if that light comes on