I purchased another 2000 Disco yesterday and the temperature gauge is at the bottom and the red danger light is on. I was told the water pump went out and blew the head gaskets and the motor was toast but when I got there to buy it I grabbed the keys and it started right up. A slight knock on one of the lifters for a second and than it went away, anyway. I did not leave it running long enough to change the temperature on the gauge but it seems to be pointing way lower than any other one I have ever owned on the gauge and the red light is always on. Would that indicate that the temp sensor is not hooked up or not functioning correctly? Just something for me to think about because I do not plan on working on it for awhile. What are your ideas/thoughts? Thanks

 

I bought mine with an overheated motor too. I wasn't as lucky as you tho, the shop found the piston rings in the oil pan, and the timing chain had sheared off all of the teeth on the gears. Anywho, once the motor was replaced, my temp gauge read correctly, but the red warning light was stuck on. If I remember correctly, it was just my temp sensor.

 

Bama,
Thanks, It just came as a thought that I would ask before I searched around for other problems in a few. It makes sense that the sensor is not working correctly because it was over 100 in AZ today and the block probably was 80-90 which would read something on the gauge when you turn the key just into the aux position instead of whatever straight down is (20 degree, I dont know) Thanks again.

 

OK. I looked in the RAVE manual for any explination and checked the block to find the temp sensor and no luck. What I thought looked like a temp sensor on the right side of the block is said to be a knock sensor. Where do I look next. There is a coolant sensor on the intake manifold that I can see but that does not give me the actual temp of the block as well as the sensor connected to the radiator, same not the block temp, so I do not think that is the problem. Any help would be appreciated.

 

What are you looking for?
The coolant temp sensor is on top of the IM at the front of the engine near the top radiator hose on the engine.

 

If you can rent an ODB sensor that reads live data you can see what the sensor is reading. There is not block temperature sensor. Also you are assuming your temp gauge in the truck is a true "gauge". Think of it as an idiot light either on or off.

 

x2 get an ODBII scanner like Scangauge and you can read live temp readings.
Or get one of these http://www.harborfreight.com/non-con...ter-96451.html

 

If I am assuming it is an on or off guage it is off. I turn the ignition on and the guage goes up to the top than falls all the way to the bottom and never comes back up. So I am guessing the sensor in the IM is bad. Am I assuming right? If not what else could it be? Another question: I have a 2001 and another 2000 and when I removed the radiator there was a sensor that plugged into the bottom of the radiator and another sensor that plugged into the transmission cooler. When I removed this radiator on this "new" 2000 there is not a plug for the sensor on the radiator only one for the transmission cooler. I looked to see if someone had bypassed it but there is not a plug or wire comming from the harness and the radiator does not have a sensor on it. Only one for the trans cooler. Weird? Does anyone know why this car would not have a sensor in the radiator and my other 2000 and 2001 both have it? Thanks for the help.

 

It could be a bad temp sensor, they are cheap so get another one and try it - or pull one out of your other truck.
Yeah they changed things as they went long, not all have a sensor on the radiator.

Edit: another thought is unplug the temp sensor and check the pins, clean the plug and then put it back and try again.

 

Bundu:
It looks like the sensor has the clips broken off of it and some different colored sealant on it so I am guessing someone has screwed with it before. I have to order a bunch of stuff from Atlantic British anyway, so I will just get another one. Why did they change the sensor on some of the Discoverys on the radiator? Thanks again.