Club 80-90 Forums

Hi guys,

I sent there's a few similar posts I've had a quick skim though but it's a bit difficult as on holiday and only have the phone to use!

We are on holiday in the t25 1.7 d with the ky engine that was rebuilt last year, we left somewhere and drive for no longer than ten minutes and I noticed the coolant light flashing and the gauge all the way to overheating so I stopped immediately. Checked the coolant level in both tanks in engine bay and they are fine, also put the hands on the hoses, ones next to engine were pretty hot and the one that runs to the front wasn't really warm, but no steam or mega high temps. Let it stand for an hour and the gauge still read full temp so I took the cable off for the single pin sensor at back of the cylinder head and it drops back down to cold, put it back on and it zooms straight up to overheating. Basically ended up driving back to the camp site and it suddenly started working again but reading over half temp, no loss of power etc. Just trying to work out what the next best step if you guys can help please?

Thanks for your time and sorry to duplicate threads!

Adam.

Maybe it's an electrical issue - an earth fault perhaps? You could try cleaning your Earth crowns. They should be on the left a-pillar below the dashboard behind the fuse box.

Ok thank you, I'll check those and the earth by the air filter. Does anyone know if there is anything else that make the temp gauge and the led show a warning? I'm thinking of trying find a new sensor somewhere local which will probably be difficult and most likely not the fix?
It looks like earth's so I'll go and buy a wire brush and electrical contact cleaner and get to work.

Quick update-
I've cleaned the earth crowns by the glovebox, a little limescaley but nothing major, cleaned the engine bay earth by the air filter and replaced the spade connection to the temp sensor. This made no change, the temp raises straight up with just ignition on and then sets the led flashing, this stays flashing all the time, sometimes the needle drops slightly back but only a little. Removed 43 relay and the temp gauge and light still fault.
Can anyone point me towards more tests, I'm going to try and get hold of a replacement temp sensor too.

Thank you.

Have a fiddle with the pcb ribbon connector under the dash. Sounds like an electrical gremlin & the pcb is the first place I'd start looking.

I pulled the dash out and disconnected the main connector to the pcb, nothing obvious there but bit hard to say. Unless I take the pcb off and give it a clean aswell maybe?

I would suspect that either the temp sender has shorted out internally or the wire to the sender has shorted to ground somewhere. What does the gauge do when the sender is disconnected? It should read cold.

Yep with ignition off or engine running if I disconnect the wire it goes to cold, hopefully collecting a new sensor to fit today, they are just a straight swap without any bleeding if your quick if I remember?