That's what I'm left wondering as well. If the gauge has been manipulated as described yet indicates when a problem begins to come about, then I wouldn't be too concerned about fiddling with it. Same with the oil pressure gauge.

Having an exact reading is nice, but knowing what the display (in the current form) means when it's something just outside of normal is more important IMHO.

 

Good point, but it would be valuable to see the beginning of a trend, and have a choice whether to slow down, pull over, or continue on. Time of day or night, difficult or easy route ahead, all play a part in the decision.

I think considering the potential cost of a major repair due to low oil pressure or high water temp, we deserve to have the most accurate information available. I am also extremely disappointed in Jaguar and BMW for taking this simplistic approach to gauge logic, considering these are cars driven by many auto enthusiasts.

The gauges in my $1,000 '66 Mustang I drove in college provided me with more information than this setup.

I'm done now.

 

I hear ya. :-) But the other 97% of owners are perfectly content with the idiot gauges.....something Jag, BMW, and all the others surely must've presumed before making the change from "real" gauges.

I spent 30+ years in the auto repair industry. I can't tell you how many times....hundreds, probably....I explained that there's no need to panic because the oil pressure is much lower at idle with a warm engine versus 2000 rpm with a cold engine. Or because the coolant temp was a higher in Las Vegas in August in city traffic than it is in on the open highway in January in Boston :-).


Cheers
DD

 

Count me in as wanting one. But in the mean time why could we not come up with an idiot light sensor that activates around 190 to 200 degrees and mount it in the hotest place in the cooling system. Then just put a small red light somewhere it will get your attention. My experience in the airplane business of building I have found it better to have both a light and a guage. The light to get your attention and the guage to tell you how bad it is. The guage alone will almost never get your attention alone.

EZDriver

 

I'd be interested in this, count me as a move it up in line vote

 

Well I am a bit more enlightened now about how this guage works
And I guess with the chart now you have an idea of what temp you are running at. It would be nice to have a nice old fashioned analog guage. I believe they make a device that has a digital display which I dont like but you can program the temp at which it gives an audible alarm which I like.
In the meantime I am getting ready to put my car away for the winter....
But will remember this in the spring and may hook up my code reader and plot my own graph. Would be interesting to see if two cars are similar. I may return to this thread or one similar when the snow starts to melt

 

I understand the existing gauge better now, but would still opt for one with "real" readings.

Put me on the list...

 

I think so-called gauges on many modern cars operate the same way. We had a 2000 Acura TL and under almost all conditions the needle was pegged just below half. It didn't matter if it was 100-degrees outside with the a/c running or 50-degrees (doesn't get much cooler here in SoCal) the needle barely moved. This was in sharp contrast to my 1995 Corvette where the gauge more accurately reflected actual conditions. I noticed that the gauge in my 2005 XKR behaves exactly like the Acura and then I read in Jaguar World Monthly about how the temp gauges in these cars only really respond under dire conditions when it is already probably too late to do anything. Worse JWM said this was by design!


Doug

 

You need to call them up and ask for a non-CAN cable. I had random faults with the standard cable, too. I had to have the non-CAN cable for my 96 Chev diesel pickup so I tried it on the XK8 and it worked. It's just missing a couple of pins in the DTC plug. They will send you one for free.

The temp chart was typed in by hand while looking at the pictures. No download capabilities from the ScanGauge that I'm aware of.

 

You would want that light to come on at 225-230 or it would be flashing all the time. My car regularly swings between 195 and 220 once it is warmed up all the way (yes, I realize I've got some cooling system maintenance to do). The high speed mode on the radiator fans isn't set to come on until 207.5 degF according to the AJ engine control specs (in one of our FAQs).

 

Roughly, yes. That is the assumption since the engineers/programmers made things look normal in that range.

Again I would assume yes, or at least slow you down to give you a hint that something was awry. (hint-RESTRICTED PERFORMANCE) The only experience I had in this regard is on my 96 Chev Diesel pickup. When towing heavy in the stock configuration, as the engine temp went past a certain point the ECM would start scaling back the power it would allow the engine to develop. I could see 100% power on the scan gauge just barely touching the accelerator pedal. Mashing it all the way to the floor did nothing else. Let it cool down and it was back to normal. I would expect the Jag and any other computer controlled engine is programmed to do the same. It won't let you kill it all at once. You have to keep at it through all of its symptoms and objections..as some souls are prone to do...

 

I would for sure be interested in having gauges that were actually correct. It does bother me that when it is 30 degrees out or 100 degrees, my gauge goes to the middle relatively quickly and never moves.

 

OK....I am convinced there is more interest than I originally had thought. I will move this project up in priority. I will look at doing coolant temperaure and oil pressure modules which reflect real data on the factory gauges.

Does anyone have a spare used main and/or a auxiliary gauge cluster they do not need to loan to me for a few months? It does not even need to be working, since I am only interested in the gauges. As a reward you will a get free conversion module once it is developed.

 

I have read several articles in JWM where an XKR or XFR was tweaked by some shop like Spires to get significantly more power and pretty much the only thing that was done was an ECU remap. NO OTHER SIGNIFICANT MODS. Basically the gains from the remap were good enough that no other mods were needed.

So why is it that there are no companies like Hypertech or LT-Edit that have figured out how to provide some handheld programmer or editing software that can be used with a laptop that would permit guys like us to do a remap?

WhiteXKR--this looks like another project for your to-do list.


Doug

 

You all may be trying to solve something that's not really a problem since most modern cars run at far higher temps than years ago. My '91 ZR-1 could run at 190-200 but was really much better at 210-220, and was still considered in its range at up to 240+. Many emissions systems require those high temps. If the Jag guage went to 80% at 220, as opposed to hanging in the 60% range at lower temps, it may be exactly where it wa intended. I think mine has crept up in that range on 100-110 degree days with the a/c on.

 

I fully agree that it is normal for these cars to run at higher temperatures at times. The utility though of a correct reading gauge is to get accustomed to normal patterns (typical idling with a/c, typical hot weather driving, etc.) and get early warning of a potential issue when the normal behavior changes.

 

Fantastic. Thanks, JagWrangler. We're all looking forward to your next bit of genius, and I love that you're including oil pressure in the project. Sign me up, baby!

 

Thanks Coupe...please be patient though...I only wrangle Jags at night.

Now added to the 'upcoming products' list on my website.

 

I agree we would want the light to come on just a little above the maximum normal tempt for a hot day. You want it to tell you something is wrong and not give false warnings. On my airplane I have a fuel pressure light that come on if the pressure drops to 2psi. The normal is 4psi. The light gets my attention and tells me to switch tanks before the engine stumbles. With just the guage I would never notice and the first thing the engine would tell me it is out of gas which is a little exciting.

If someone knows of a location in the cooling system that could be tapped into to place a sensor that would help and I would try it.

EZDriver

 

Just happen to have an extra aux cluster, be glad to send to you! Still have your address, want me to send it on up?