98 A3 1.8t Coolant Light

[revo_20vt]

Good morning all, recently when starting my car in the mornings I am getting the big red coolant warning light flashing up on the screen, this will only happen in the mornings when I start the car, and if I turn the car off and turn it back on it usually sorts the problem (sometimes I have to do it twice.) Anyway I checked the coolant level which is in between Min and Max so im thinking that is ok???????? Any ideas on what the problem could be

[loki]

Good morning all, recently when starting my car in the mornings I am getting the big red coolant warning light flashing up on the screen, this will only happen in the mornings when I start the car, and if I turn the car off and turn it back on it usually sorts the problem (sometimes I have to do it twice.) Anyway I checked the coolant level which is in between Min and Max so im thinking that is ok???????? Any ideas on what the problem could be

If it's only started in the colder weather, then it's simply due to it being colder and the coolant has less volume as a result (so the sensor thinks it's low). If you have checked it and it is between the min and max, then there is nothing to worry about presuming it goes off.

No harm in checking the cap is screwed on tight and there are no leaks (will most likely show up as green residue where it is leaking).

[robert_cannon]

First I've heard of a liquid loosing volume in cold conditions

I'm having exactly the same problem. Cold mornings the low coolent light comes one and then goes if I re-start. Hower the pattern I'm noticing is it only happens if I park on the other side of the street where the camber leans the car over to the drivers side.

Maybe it just neads a teaspoon more - they do seem a bit overly sensitive.

[revo_20vt]

I just find it strange how last year in the cold weather I didnt have a problem with the light turning on in the mornings, could i just put a little bit of water in there or will i need to put more coolant in to see if it stops it

[robert_cannon]

I just find it strange how last year in the cold weather I didnt have a problem with the light turning on in the mornings, could i just put a little bit of water in there or will i need to put more coolant in to see if it stops it

From what I've been reading it's possible that the contacts need cleaning or the internal element inside the expansion tank has crudded up. As you say mine is also bang on between the min and max too. Think I'll take the expansion tank off at the weekend and give it a clean out.

[loki]

I would personally just top it up a little and check for any residue, sounds most likely that you are loosing a little somewhere.

[revo_20vt]

I have heard that you shouldnt mix the coolant that you put in?????? would it be fine to just add a little water?

[robert_cannon]

I would personally just top it up a little and check for any residue, sounds most likely that you are loosing a little somewhere.

Tis bone dry Loki, the levels haven't changes at all in 12 months. I wreckon it's just mad. Did it again this morning. I'll clean the internal prongs within the expansion tank and let you know if that solves the problem.

Another school of thought is that if a battery is weak or weakend by the colder temp there's not enough charge to transmit current where the probes are sitting in the coolent. This theory would explain why it works after re-starting the car as the alti would have shoved a few extra vlts in the battery Tis all a guess though

[dfilogik]

I had this problem for a month on my Audi A3 1.8t 1999. Strangely it started happening only after I had the engine oil changed. Just yesterday, the oil filter sub assembly came off the crankcase and spilled oil all over the engine bay, bringing the engine to a complete halt. On careful inspection, realised that the threaded shaft holding the oil filter to the crankcase was damaged. Not sure if this had anything to do with the big red coolant indicator, which again went off only in the morning, when it was cold.