Water temperature sensors

[Harvy500]

After a quick search, I'm assuming the single blade sensor is the dash guage and the 'vertical' one with a 2 pin plug is the ECU sensor.
I've got my dash water temp needle doing weird things.

[Johno]

Correct.

I would also consider to do the ‘Caterham” water temp mod, moving the gauge reading sensor next to the ECU sensor, I found it works very well compared to the original position.

[Harvy500]

Ok, I've researched it and ordered the new sensor. Just got home so I thought I'd double check my car has the right hole. Yes it has BUT.... What's this little thing that's in there now? I unplugged the ECU sensor for a clearer picture. It isn't or wasn't plugged in to anything.
At least I know where to put the new sensor. Thanks for the advice.

[AlfaSpider]

Having just changed mine for the caterham sensor it makes a huge difference it’s now within 3 degrees of the reading on rover gauge.
The part that’s screwed in there is a temperature sender for a different type of gauge.

[Harvy500]

Thanks for that. The correct one is on its way.

Edited by Harvy500 on Saturday 20th December 18:46

[Belle427]

Wasn't that top one the original range rover position but Tvr chose to do it differently!

[Harvy500]

Belle427 said:

Wasn't that top one the original range rover position but Tvr chose to do it differently!

Who knows? Lol

[Harvy500]

The new guage sensor arrived.
Still waiting for the ECU sensor.
Picture of what I've got.
It's a Smiths sensor.
It's fitted, wired but not tested and won't be until the ECU sensor comes.

Edited by Harvy500 on Saturday 27th December 19:40

[Harvy500]

[Wildfire]

Johno said:

Correct.

I would also consider to do the Caterham water temp mod, moving the gauge reading sensor next to the ECU sensor, I found it works very well compared to the original position.

Hi Johno, what's the Caterham mod? Is it just moving the sensor? I have always had problems with the gauge on my Pre-cat. I do have a spare sensor somewhere.

[Harvy500]

If you look at the top picture you can see 2 sensors. Usually the single headed sensor isn't there. Blanked off somehow.
The bigger plug sensor is the ECU sensor. Standard is to use the lower middle sensor.
I've just put my new ECU sensor and the new dash sensor in. All I had to do was take the smaller sensor out and replaced it with the single blade sensor using the as was flat wiring single connector.
Much more accurate dash reading now!
Fans kick in when the should etc.
One thing.... The ECU censor I removed was a blue body. The new one is a black body. Is it simply colour or is the colour indicative of resistance or something?

[Beverley Grove]

Followed this post, did a bit of background reading and my sensor arrived today. Fitted and much more responsive in line with RoverGauge.

Edited by Beverley Grove on Saturday 10th January 16:44

[Johno]

Wildfire said:

Johno said:

Correct.

I would also consider to do the Caterham water temp mod, moving the gauge reading sensor next to the ECU sensor, I found it works very well compared to the original position.

Hi Johno, what's the Caterham mod? Is it just moving the sensor? I have always had problems with the gauge on my Pre-cat. I do have a spare sensor somewhere.

Not sure it'd work for the pre-cat's as the gauges are different. The sensor in question is a std for Caterham with Caerbont gauges which relocates the sensor to next to the ECU sensor - with correct thread - which means no need for the extender TVR used in it's original location and is prone to inaccuracy.

[Beverley Grove]

For the earlier gauges, my understanding is to use the original unused LR sensor (rather than replace with caterham) & put an approx 150 ohm resistor inline.
The temp curve isn’t correct but is more responsive as per the later Caerbont gauge/Caterham mod.
Some have calibrated for running temp using a variable resistor then replaced with a fixed resistor.

[spikep]

Beverley Grove said:

For the earlier gauges, my understanding is to use the original unused LR sensor (rather than replace with caterham) & put an approx 150 ohm resistor inline.

If you go back to the original thread by, I think, ‘Chimp on gas’, he originated this with the 150 ohm resistor. But after running for a number of years realised that although during normal operation the temp reading was accurate, the resistor also prevented the gauge from climbing to the top of the gauge and therefore it would not indicate that the system was overheating.

[BIG DUNC]

My pre-cat is standard and I have never had any issues with the temperature gauge.
I have not compared it to Rover Gauge or anything else, but it is consistent and provides sensible readings.