Low Coolant Level Dash Light On.

[CaptainP 2]

I had the low coolant dash light flash on yesterday when I was driving the CTI. Came home and checked and the levels were all okay. I went out this afternoon and immediately the light on the dash came on again whilst parked in the drive. I unplugged the connector to the sensor on the expansion tank and obviously the light went out. Do you think this is down to a dicky sensor as I know these can be tempormental over time or is there something more sinister going on?

Thanks

Steve

[Anthony 1,003]

Phase 2 level sensors can suffer from interference from the ignition system and falsely illuminate the light, but Phase 1 sensors (as yours should have being an 1989 model) are generally pretty good - usually if they fail they fail so that they never display the warning light rather than randomly coming on.

 

When you say that the level is OK, is the tank over half full so that the coolant level is part way up the plastic thing in the expansion tank? Might just be a case that the coolant level is just about low enough to trigger the light intermittently.

 

Otherwise, replace the sensor if the fault persists.

[sport1901966 8]

I have just had a similar problem, I think the sensors can get stuck over time, limescale build up or similar. Mine had stuck with the light on permanently. I've just replaced the sensor and the problem is solved. I ended up having to buy a whole expansion tank though

[CaptainP 2]

Cheers guys, will take a look.

[JoshGti 8]

I literally finished renewing mine today, cost me £1.49 for a new reed switch and some of my time.

 

I pulled mine apart as it wasnt working, turns out it was stuck due to lime scale but I decided to renew it fully anyway.

 

I Un-clipped the top and pulled the sensor loom out, which broke it in the process. Used a 13mm drill bit to remove all the brown sealant in the top half of the tube and and a long 7mm drill bit to remove the crud from the lower half the tube. Resoldered a new reed switch in from Maplins, filled the tube with tiger seal, dipped in the freshly made sensor circuit and it will probably now outlast the car!

[ORB 227 1 Cars]

I mixed of some kettle descaler in a Pyrex bowl and chucked the sensor in over night. A lot of crap came out but it fixed it...