2008 Octavia - Engine Coolant Warning Light

[napperd]

so as the topic states I have an issue with the Engine Coolant Warning Light. It is flashing RED!. I searched through some posts here already for solutions. As suggested I emptied the coolant tank and cleaned the contacts. This didn't work as once refilled and the engine restarted the light was flashing again. I then bought a new sensor and replaced that. I left the car running momentarily, took it for a quick spin and the issue seemed to have been resolved. However a number of hours later I drove about half a mile before the warning light began flashing again. The temp gauge is sitting bang in the middle, as it always has so the engine is not overheating.

I'm not sure what else to do, any suggestions from anyone? I have had awful bad luck with the car over the last 9 months. DMF replaced, rear wheel bearing, discs & pads replaced due to pistons not releasing and pads wore down in no time. This issue with the Coolant Warning light. I spent €650 trying to get the air con fixed bit still to no avail. Dealer doesn't know what's wrong with it so any help you can offer me on this I would greatly accept.

Thanks in advance

[bigjohn]

Do you have a slow leak?

 

Check the radiator for any coolant staining. Fully check the header tank itself - they can become brittle and crack - especially if disturbed. Likewise check all hoses. Make sure you don't have wet carpets in the passenger footwell - if you have what colour is the water if you mop it up with kitchen roll? The heater matrix can eventually fail.

[napperd]

Thanks bigjohn,

I'm 99% sure I've no leaks. (No obvious ones at least.) The coolant level has been constant, The plastic cover/guard on the underside of the engine is bone dry as are the carpets in the footwell. I'll check the carpets again tomorrow though just to make sure. The heater matrix actually went on my last car (Golf). I'll also take a look at the rad.

 

I forgot to mention that the warning light came on about two months ago but disappeared after about 10 mins again. 

Yesterday for a warning light came on indicating that a bulb was blown. It went again after a few minutes and  I can see no bulb that is not working.

[Jevpls]

6 hours ago, napperd said:

Yesterday for a warning light came on indicating that a bulb was blown. It went again after a few minutes and  I can see no bulb that is not working.

 

I've had a few such occasions with bad bulb warning but actually all bulbs being fine. I guess these things might not be connected.

[erindad]

IIRC there are two temperature sensors, one in the radiator or radiator hose and one on or near the thermostat housing.  I think one controls the fan motors and has something to do with the A/C. and the other talks to the ECU.   

 Don't know if there is a difference between the engines (petrol or diesel)

[pikpilot]

Check the wiring for rubbed through insulation, poor connections, intermittent breaks on sharp radius bends.

[axelgrinder]

Coming to this post quite late, but on my 1.8 tsi - I had frequent Engine Coolant red light coming on and off intermittently - and was losing a small amount of coolant over a period of a few months - discovered in the end that it was a water pump issue which is apparently a common problem on skoda octavias be they diesel or petrol. The leak never actually manifested itself as was so minor that the coolant would evaporate - in my case new water pump was about £450 , as to access it, the inlet manifold had to come off

 

Good luck and I hope you find it is something less drastic than in my case

[napperd]

Thanks for the replies, sorry for the late response.

I had to get the bearings done in the back wheel so asked the mechanic to check out the warning light. Of course the morning I brought it down to him the light never came on. They checked it out and said they could find no fault. I drove it the following day and after about 150 miles the warning light came on. It's been on and off intermittently since but has been off more than on so I guess I'll just have to keep an eye on it.

Thanks again for the replies and suggestions.

Much appreciated