my old 2 litre turbo 940 needs a water temp gauge and I haven't got time to properly fix the suspect instrument cluster. Looking on Ebay I see loads of temp gauge kits for about £6 (including sensor and wire!) and even more of a bargain the aluminium adapter block that sits in the line £5. These come in various sizes so my question does anyone know what inner diameter (in mm) the radiator top hoses, as that is where I was going to place it.

If you have the time to mount an aftermarket gauge and devise a mount for the aftermarket sensor you certainly have the time to fix the problem properly. Did you ground the wire to the temp sensor with the key in the "on" position and observe the gauge. If the gauge went to full hot the problem is the sensor. If it didn't move and all your fuses are good, then yes, the gauge may be bad. The cluster is easily removed and disassembled to replace a bad gauge. The sensor can be removed and replaced with practically no loss of coolant (done with a cold engine and leave the cap on). Given that you cited prices in Pounds the parts clusters I have may not be of any help to you but surely there must be sources on your side of the pond. -- Dave

Thanks for the advice Dave, Im quite rightly chastised for trying to sort the problem from indoors in the warm rather than outside with my head under the bonnet. I'll check out the temp sensor when it stops raining and take it from there. V. interesting that you can whip out the sensor without loosing coolant also.

Had a quick look at the FAQ but couldn't see the bit that told you which of the two temp sensors was the one that fed the gauge on a turbo 2.0L, you don't happen to know do you? If not I'll read more thoroughly later.

regards

It'll be the single pole sensor-with a yellow wire, I think. The double wire sensor is for the fuel injection. -- Dave

Thanks Dave,
Bought the coolant guage sensor (cyl head) 2 wire connector. Linked it onto the connector and stuck it in my tea, the gauge shows working so thats good. Looks a swine to fit but will give it a try. Have got an old box spanner and want to try cutting 4 off the faces away, leaving 2 which will miss the connector, mole grip the flats and see if it moves. Might be lucky. If not its inlet manifold off etc.