Hi everybody:

I understand the temp guage ( I have 99 xk8 convert ) is not really an analog device. Its reads good then bad as temp climbs above a preset level. I and I am sure others must think this is silly. My question is really has anyone either interfaced the oem guage to read proper or installed an aftermarket guage that actually tells the coolant temp. I am thinking about doing this as I think this should be done

Howard

 

I've got a ScanGaugeII that I plug into the DTC port and keep the engine coolant temp up on it so I can see what it's really doing. You can read four variables at once out of a list of about fifteen. It is "impressive" how the gauge on the panel will stay at the mid point while the ScanGauge will range between 180 and 225. The car's computer knows how hot the engine is even if we aren't supposed to see it.

The ScanGauge is also useful for reading and clearing the standard OBD2 fault codes. It doesn't show the upper level Jag specific codes.

The speedo is off, too. I hate to think what the oil pressure is really doing...

If you look into and decide to order one of these you need to ask for the NON-CAN cable. The standard universal cable will cause mass confusion with the computers and many faults. The non-CAN cable has not had any faults generated.

 

That gives me an idea given the several electronic gurus here on the forum. I also think the stock temp gauge setup is boneheaded in that it is not really giving an indication of the temperature but only a good/bad indication. I had read in one of the Jaguar World Monthly columns a month or so ago that this was by design. I wonder if something can be installed within the existing circuitry that will convert the existing gauge into a real temperature gauge.

Doug

 

I heard the oil pressure guage is the same way. Will read normal until a certian low pressure occurs in the engine, then it will suddenly drop to a low reading.

I think these guages should be seen as warning lights in the form of a gauge, nothing more.

 

Our cars do not even have analog oil pressure senders, just a low pressure switch....the oil pressure gauge is a total illusion. The gauges are computer driven stepper motors.

Doug, that is a pretty good product idea if it can be done at a low enough price point.

 

Why Bother? Lifes to short to become obsessed with gauges. The ECM knows what temp/pressures are in spec, and if they,re not it gives a warning to take the appropriate action. The reason the gauges are as they are is to because not every driver is technically inclined, and the first buyers of these cars were certainly not, and to those people, seeing the oil pressure drop to @18psi or less at 650rpm when standing a traffic lights in a car they have just paid £70,000 for could induce a coronary.
The analogue read outs are really just a visual reassurance, strictly speaking all you really need with modern cars is the speedo and a fuel gauge.
But wouldn,t that be so ****"%g boring!
Bob

 

The last car I had (1995 Corvette) not only had an analog temperature gauge that was a real gauge but also a digital readout. It turns out that these were really 2 different readings (one was coolant temperature and the other was block temperature) but you had plenty of warning that something was going wrong. And I don't mean minutes but sometimes days or weeks of warning. For example, I noticed my analog gauge had been reading somewhat higher than normal (probably not high enough to trigger any sort of warning on the type of system used in our cars). Still, something looked funny so I had my mechanic check it out. It turned out the water pump was in the process of going south so I had it replaced. With our cars, we would get no warning until the pump essentially fails. In other words, by the time the gauges in our cars tell you something it is way too late!


Doug

 

Doug,
I tend to disagree with you on the temp gauge, I think it gives a true but "Damped" response to temperature. OK it dosn,t go up and down like a ****** draws with every few degrees of coolant temp difference but a sustained increase will show, as I found out on my first XK. I had a similar occurance to yours, my temp gauge was reading above "Normal" for a few days, so checked the obvious in the cooling system and found the regulator was about to fail completely.
OK, I shot myself in the foot with last post, But!...... all you really need is a speedo,fuel gauge, and some sort of temperature indication then!....... just in case.
Bob

 

One of the reasons I loved Mercedes gauges so much. Accurate readings and condition aimed at knowlegable drivers. When normal oil pressure in the summer can fall to 3 psi at idle, it was always refreshing to see it jump right to the limit once you stepped on it. Same for the non linear fuel gauge.

 

This is an old posting. My company now offers a solution. See https://www.jaguarforums.com/forum/x...04/#post525886

 

To the point: More and more mfrs are now deleting even the temperature gauge. They've learned previously that many people would add oil if their oil-pressure reading was low, so they deleted the oil-pressure gauge awhile back. Not sure how people were responding to low temp readings. Not sure I want to know.

Remember the phrase "idiot lights"?

 

I have replaced thermostat and housing, new water pump, and a rad flush with coolant change. Although the temp gauge is in the middle I have a feeling the car is running a bit hot. When I get out of the car if feels hot underneath. (new trany as well)

European car repair specialists gave it a green light.

What else can I check to make sure I am not going to be on the road side with an instant HOT reading on the temp gauge.

Maybe I am being too picky? How can i check coolant mixture ratio to water?

 

I don't know how you'd measure water vs. antifreeze, but auto stores sell little coolant testers that show what outside temperature you are protected to, e.g. 32F, 20F, 0F or below. Looks like an eyedropper with little floating ***** in it.

 

There's several brands of coolant tester available. This is one from Prestone:



To use it, draw coolant from the Expansion Tank into tester and read the strength off the scale.



This one is available through Walmart.

Graham

 

The antifreeze testers measure the density or specific gravity of the coolant, just like the battery testers with the floating *****. But why all the discussion on measuring temperature? Hasn't everyone checked out the Realgauge kit from whitexkr?

 

If you have a obd-ii reader, one of the parameters it can read is coolant temperature. You can leave it hooked up for a long drive and see what it looks like.

 

I have a 1998 XK8 and I came very close to cooking my engine because the gauge was reading normal & BANG!!! it jumped into the red and then the red light came on & I was in traffic with no place to pull over. Had the gauge showed the climb so I could have seen the heating up problem, I would have pulled over and allowed the car to cool down then take it to my mechanic ASAP. But because gauge was such a piece of junk, I almost destroyed my engine. I had to replace the thermostat, water pump and housing.

I little warning would have been really nice. I have been thinking of installing after market oil & temp gauges. I am pretty sure it would even fit in the stock location and if you pick a nice gauge, it wouldn't look out of place. The gauges come with their own sender units so all you would need to do is run a couple of wires and your in! working gauges.

 

Would be cool if I could display water temp on my dash. I already have a trip counter, mpg, etc, If other scanners can read it why can't the message display center read it and display actual coolant temp. mmmmmmmmmmmm

 

Read message #10 in this thread. I have the temp gauge upgrade installed and it works great. OEM gauge remains in place, but actually works now.

 

A few years ago after an overheat scare I installed a digital gauge on my '97. Since I did not want to replace one of the Jag gauges with a non matching one I was able, with a little backyard fab work, to install it in the flip out glasses holder This way it can be hidden or left open. The sender I installed in the heater hose. Seems to work well but the temp these engines run on a hot day at a long stoplight will scare you before the fans kick on and she cools down some. I have seen it go as high as 135 on a real hot day and the jag gauge is still dead center. I think White XKR has now come up with the better mouse trap but at the time this worked for me.