[RedArrow]

As first step it would be great to check and refurb the existing temperature gauge.

You could check the terminal at the front of the engine, right at the very front on cylinder one, on the driver side of the engine (not for you in the UK but in the usa... it is the left side of the car LOL), so check there to see if the wire that runs to the sensor is intact.

There`s leaks and corrosion and also gravitation, so there`s a chance that the connection is bad there (your instr cluster doesnt get the signal from that spot)

The other temp sensor is located in the very rear of the engine near the firewall, behind the IP, which is another temp sensor that is the same, measuring temps for the glowplug relay.
If the temps are warm enough, the glowplug relay doesnt activate the plugs.

Why I`m saying this is that those two sensors are totally the same exact parts and technically you could use the front in the rear and the rear one at the front.

If this helps for testing the system, that could be done too.

I have an engine on the stand and can take picture for you of both sensors. In the rear there is very tight access only.
I`d start by checking and cleaning the surface of the pin of that sensor, then testing the front sensor somehow or maybe measure continuity on the wire.

On certain d24 cars the glowplug wiring also attaches to that area on cyl one so there`s a change that somehow the wire to the sensor was disturbed, chafed, removed, etc. Take pictures and post some

Take a look at this picture. It shows both temp sensors: there`s the one at front to the left of the first glow plug, towards the front... and you can see the one in the back of the head also. It is a d24t but d24 engines have the same configuration.


Your top hose being hot is very normal, do not worry about it too much for now, it really is where the `used hot` coolant exits the motor and is shooting for the radiator to get cooled down in there and then get transferred back into the engine via the lower hose.

The 1995 TIC TD cars are probably very nice! I thought they had already the coolant level sensor for those model years in Europe. Doesn`t your coolant expansion reservoir have a level sensor in it?? If you see electric wires going into it or under the tank, then yes which would be good news. If not, then you can always update your system to have such, by swapping in a sensored reservoir from a younger car and have it wired up to a gauge or an audible alarm or both. A level sensor is as equally great to have as the temperature sensor itself is.
I keep seeing the 850 960 cars in the junkyards and already took home a small-sized reservoir with the level sensor but never made it to have it wired up. It is mainly about the relocation of the existing reservoir and making a new bracket that looks near stock; so that`s why I kept delaying the project.



((A sidenote and general advice to everyone: try keeping all of the coolant hoses free of *all kinds of* cleaners, chemicals such as engine shine, armorall, etc, including dirt, dust, even motor oil, diesel vapor, power steering fluid and literally: everything. Wipe them clean with soapy water, a towel; and try to keep them clean as much as possible at all times.))