So here it is......


In my first round of diagnosing the issues in the LR3 engine, I have noticed the coolant temp sensor in inop. With that, I remember hearing that the PO had replaced the T-Stat housing which was the beginning of the engine issue.
Having read the links on my searches, I can see the Sensor may go unconnected? Is it "Inside the housing" or just in the area of all the stuff. I know when my gauge was wonky in my Saab, I just unscrewed it from the block and screwed another back in. But even the bad one showed some sign of working albeit intermittently.


I want to know if I need to remove or disconnect the T-Stat housing to see if the sensor is properly connected.

 

It is easy to get to. see attached photo. If you do suspect the sensor as being bad, they are only $20/delivered.

 

Thanks. I'll check it out when I get home.

 

If you have not done so before, I suggest changing the entire assembly, it's not that much more. Includes all you see in the picture Erik posted. They are notorious for cracking in various places.

 

I almost think your coolant sensor is working. I say that as it seems that if it is not, the engine tends to just quit or really act in a miserable manner.

I recall a few years back where a mouse had eaten the wiring going to the sensor and as it is located under that black plastic engine "sound" shield, mouse feasts are not that obvious.

And yes, if you are going to change the sensor, per the post above, take the opportunity to change out the whole assembly. You get a new sensor, a new thermostat and most importantly, all new plastic.

Additionally, the thermostat is probably put in correctly - not that easy a task. Pour in all new coolant as well and you will be set for a couple of years.

Change out the bleeder tee also hidden under the sound cover, part number LR027661, while you are doing all that as that tee is usually the first cooling system plastic to fail.

 

I reread your first post re the temperature gauge not seeming to work. I just remembered the trouble a guy in Africa had and the primary symptom was that the temperature gauge did not indicate - it was sometimes dead, and sometimes just erratic.

After replacing just about everything that could be replaced in the engine compartment, for some reason, he pulled the instrument panel out. That single multiconnector that feeds the whole cluster was a bit loose for no apparent reason. Replugging it back in solved all the problems. It seems that connector sometimes loosens and the hint is the temperature gauge acting up.

If the previous owner recently replaced that whole plastic thermostat housing business, then you have a new coolant sensor already. Look at the wiring / plug as you said, and then think about removing the instrument binnacle and just unplugging and then plugging the connector back in.

Right at the end of the video, it shows the connector. Also I think there are easier ways to get at the cluster on an LR3 than shown for the RRS.

https://www.youtube.com/watch?v=0twl...ature=youtu.be

 

Everything looks connected as I can see. So I think it will be much deeper than just a simple fix. I plan on starting to tear down the engine at the end of the week. I will look at the housing and connectors while I have the engine disconnected to do the swap.

 

Yes, I tend to agree and that is why I suggested checking the electrical plug behind/to the instrument cluster.

Also located on the instrument cluster PCB is the backup memory chip for the main computer chip which is located on the PCB behind the passenger side fuse box. If the two chips are not able to talk to each other, the computer is unhappy and one indication of that is that the temp gauge does not indicate.

 

Does this particular vehicle have one or more blown head gaskets?

 

Won't know until it's out of the rig and I take a look. But I will let you know for future reference when I get around to it. I started it last night for the first time in a few days. She started real rough and lots of coolant was burning off the engine.