The temperate gauge on my 1974 xke has been working fine.
Under normal consitions the guage needle was above the
first half of the word ''NORMAL'' - so between ''O'' and ''R''.
After a Highway run in the summer it moved up to between
''A'' and ''L''.
Last week, the temperture guage did not move at all. I
replaced the sender which looked like it was the original.
I installed a new one from SNG Barrett part number
DAC2583#. After the install the guage needel is moving to
the end of the word ''NORMAL'' and stays at ''L''.
What has happend ? Is the new guage showing a false
reading or has my car alwys been running hot ? Does anyone
has experianced the same ? Thanks.

 

It's probably OK, one way to check is to use an infra red thermometer on the engine temp sender. I thought my Series 2 was running hot because the needle on the temp gauge was in a similar place between the N and H but it was reading around 205 F. The cooling fans don't even come on until the temp reaches 205F.


andy

 

I remember Road and Track commenting on the change from a temp gauge with numeric markings to the type with cold-normal-hot markings, in theory to make things less worrisome for the driver. The author said "Again missing the boat, Jaguar calibrated the gauge so that the needle reads somewhat high on the scale at normal operating temperature"

One thing that has always troubled me, though, is that the DAC2583 has become the 'works on everything' part number for virtually every Jag from the early 1960s (perhaps even earlier) thru early 1990s, (perhaps even later). Add to that that most vendors sell an aftermarket part.

I have to wonder if the senders being sold really *are* compatible/correct for such a wide range of applications. Maybe so, but it just doesn't sound right to me.

For example, owners of older Corvettes know that you can't use 'just any' sending unit....even though many vendors sell the same sending unit for Corvettes as used on a wide variety of GM cars, claiming, erroneously, that it'll work properly.

Perhaps some vendors will chime in.


Cheers
DD

 

Thank you for the reply's.
I will measure the temperature with a laser and let you know the reading. I have the feeling that the sender is more sensitive.

Indeed, DAC2583 is a very common part. It would not surprise me if the Jaguar calibrated gauge shows higher reading.

I will get back with the actual reading.

 

The temperature on the sender is around 195 F. The engine block shows around 205-210 F at some parts.
After stopping the engine I measured again and then the sender unit temperature increased to 205 F. The guage at that point was slightly passed "NORMAL".
The gives me the conclusion that the new sender unit shows a high temperature at the guage then the original one.
Should anyone know how to calibrate the sender or where to find an "orginal" one, please let me know.
Thank you all for helping and contributing to my post.

 

Sorry that I am not familiar with your year, but isn't the sender located on the intake manifold? Block temp is not where you want to check the actual temperature...Do you know which thermostat is installed in the cooling system?
Try again, and this time , take the temp both at the intake manifold, near the sender, and at the top and bottom of the radiator...
To me, 195 degrees at the sender is slightly above "normal", depending on the thermostat that is installed..

 

If you are using a infrared thermometer always shoot the sending unit area and "most important" shoot the lower hose where it leaves the rad, do this with the fans on, then shoot the top hose ! Now if you get 20degrees cooler reading at the bottom hose you know the rad is working properly, the fans are doing there job, and the water pump is working properly ! Now if your good and very careful you can disassemble the gage and make it read the same value as the infrared (there is a fine metal strip (bimetal) that can be carefully bent to make the gage read higher or lower ! Make it match the in fared thermometer.

 

I am currently rebuilding the carburetors. January is a good month for that here on the northeast coast. As soon as I can start the car again, I will test the temperatures. I have also found an original but unused temperture sender. It will be interesting to see what the guage will show after I install that sender.
I hope to be able to post the update within the next six weeks.

 

I have installed a new aluminium radiator and new fans. The temperature on the thermostate housings and the hoses leading into the radiator reads between 185 (85c) to 205 (95c). The coolant expansion tank reads between 195 (90c) to 215 (100c). The radiator reads on the top 175 (80c) and on the bottom between 150 (65c) and 80 (30c). The front top of the camcovers read between 210 (100c) tp 240 (115c) representing the highest temperature point of the engine. Usually I get the higher temperature readings after driving on the highway 70+ mph for an extented time on a summer day.
The water guage shows me a reading at the end of "normal" area - just on top of the 'l'. After getting of the highway and sitting on a traffic light, the guage goes up in between the 'normal' and 'H'.
Are the temperaturs and readings normal ?

 

The cam cover temp isn't really important...The cooled surfaces , like the hoses ,radiator,intake manifold...Those are the ones that count...

Only other temp, would be the exhaust manifold temp, taken near the top of the manifold...
Each outlet should be about the same...When hot, in the 400-450 F range...Can be slightly higher, but not much lower...Significant (100 degree +-) differences there, can mean coolant leaks into the head.
Based on your figures, I think you are doing fine.
Edward

 

It's likely a sender issue. I had the exact same issue with my '73 when the temp sending unit failed. I ordered a replacement from a well known parts supplier who assured me the superseded part would work just fine. It did work but it also read high. I eventually found and OEM sending unit on Ebay, installed it and then everything was as it was before my old temp sender failed. Find an OEM sender and it will solve your problem.