Hi all,

 

My Temperature warning light has come on a couple of times in the last week.

 

However the temperature is at 90 where it should be, and the coolant level is fine. Came on about 15 minutes into both journeys, turned the car off, and an hour later it was running fine again.

 

Any idea's what could be causing it?

Welcome.

The temp indicates 90*oC, does not mean it is at 90*oC.

 

Maybe tell what car / engine you have and somebody might be along that can help you.

Tell you what sensor / wires or whatever to check.

Sounds like you’ve got a faulty temp sensor, changing your coolant expansion tank should cure it. 

Never heard of a temp sensor in the expansion tank, only level probes.  They can play up on various iterations of Skodas/VWs,

 

Here's a free 'degrees C'  if anyone wants to copy it -      °C

 

 

 

 

 

My bad, was rushing.

 

Its an 2008 octavia 1.9 tdi 105 bhp.

 

Water pump change due in 8k and 9 months.

 

AA were no help by the time they got to me 1st time it went off, 2.5 hrs after the call was made. No fault when they turned up to investigate. But came back a few days later.

18 hours ago, Mumbles260486 said:

Its an 2008 octavia 1.9 tdi 105 bhp

As sort of discussed already, it's an issue with the water level sensor, not an actual temperature warning.

 

Is the water level correct(ish) in the expansion tank? If so, on a cold engine, open the expansion tank. If you can see 2 prongs descending into the coolant, scrape a wide flat blade screwdriver down both of them several times. This should cure the problem for several months or years. If you can't see these prongs, a new expansion tank will cure the issue for several years at a cost of about £20 and 15 minutes in a decent independent garage.

Cheers. Bought a new expansion tank. Had seen a few posts about the prongs, but all were on a cold start, not halfway into a journey. Just gonna see and hope it doesn't come back

Changed the expansion tank yesterday.

Fault came back again today. Faulty temp sensor?

Only fault code is 05697, can't find a description of the code anywhere.