Coolant warning light comes on in morning....

[Niche Market]

Hi all,

Last few weeks coolant warning light (red thermometer) has been coming on when the car is first started in the morning. No beeps, but stays on and temperature gauge goes up to middle and stays there, as normal. Coolant is obviously not over-heated and level is fine (the two things that the manual says could normally cause this warning light to come on).

I found a few threads with similiar symptoms, but wondered whether replacing the sensor in the expansion tank was a pretty safe bet to solve this?

If not it's off to the dealers

[Fasterbaby]

I would bet it is the temp sensor, i have read a few reports of those going faulty. Can you get it VAG COM tested?

[TaviaRS]

Temp sender, I had 4 go on my old RS. All done under warranty

[uptheposh]

Looks like I'm off to the dealers too then, I've got the red light coming on in the morning when I first start the car, if I then restart it dissapears.

[simontreen]

Ooh crikey - me too...SWMBO reported the same fault yesterday morning.

Hi ho hi ho it's off to the dealers we go!

[CHRIS ELLIS]

Mines been doing it for ages had a new one under warrenty still doing it.turn the engine off then back on stops it every time.its annoying so i just live with it now doesn't do it when above 5C .30000 miles on mine

[carlos]

Exactly the same thing happened to me 52 plate octyvRS 40000 miles on the clock, just happened forthe first time when it was -1.

saw the thread last week took it to the dealer and it was the sensor,

. I mentioned that i thought this was a commen problem but he wouldn't admit it was, seems like it is to me are you giys all around the 40000 mark 2 years old???

Carlos :thumbdwn:

[Niche Market]

Looks like I'll just put up with it for a while then, car's just out of warranty (only done 21K though).

Or may be I should just move to Spain

[Goochie]

Mine did it the other morning - cured by screwing the header tank cap back on..... the dealer had left it rattling round by the wing (lucky I diddnt loose it)

[Niche Market]

Unplugged the connector from the header tank, cleaned the contacts, applied a little vaseline to them and re-connected, has been fine for the last couple of days, but it hasn't been so cold.

Forecast is cold for the weekend, so we'll see how it goes.

Cheers

Tim

[rpallett]

Had the same problem on me old Y reg Octy Ambient.... took it back in and was told a special coolent was used, so they emptied tank put new stuff in and i brought a bottle of it off them. It was fine from then on.

Changed car since then though and I've never had to top up my coolent in all the time of having my '02 4X4 Octy and it didnt bleep or flash last year... so watch this space!

[vRS_Si]

I had this problem this morning.

A couple of beeps and then a flashing coolant light.

The levels fine and after an hour drive to work the engine temp was fine.

I had the temperature sensor replaced about 3months ago but looks like i might be going back for another.... :(

[DaveH]

You don't have the key in position 2 for a while before starting do you? I don't get any warnings if I start the car straight away but I noticed when I did the recalibration of the throttle body thing (ign pos 2, door open then wait) it flashed the coolant light and beeped at me. RossTech say the coolant needs to be between 5

[vRS_Si]

I did have the door open as i was de-icing the car at the time.

I'll have to try turning the ignition off, shutting the door and trying again if it happens over the next few days again.

[DaveH]

I did have the door open as i was de-icing the car at the time.

I'll have to try turning the ignition off' date=' shutting the door and trying again if it happens over the next few days again.[/quote']

It does sound like you were doing an involuntary throttle body recal, the warning is then to tell you it can't do it as the coolant (and therefore the engine) is too cold.

[Goochie]

Discovered mine only does it when the car is parked with its nose up-hill on my not-insignificant slope of a driveway.

[uptheposh]

Took my car to the dealer to be checked today. They diagnosed a faulty temperature sensor/transmitter and replaced it under warranty. The sensor is part of the coolant reservoir so I've got a new one of those as well!

I got the impression from the dealer that this happens a lot, I wonder if this is a recurrent problem for all VAG cars?

[bengie]

mine started today too, but stopped later when a bit warm. might check level later just to be sure. does coolant loose its cooling properties?

[pdhealy]

I have had that problem too. The dealer replaced the sensor & the expansion tank under warranty. Fairly common problem judging by the preceding posts.

I have had thermostat & water pump failure driving at -5 (at low revs), thankfully covered under warranty too!

[pdhealy]

mine started today too, but stopped later when a bit warm. might check level later just to be sure. does coolant loose its cooling properties?

I think it loses efficiency if left exposed to air for very long.

[Fasterbaby]

How much are these sensors to buy? Because when warranty runs out it looks like a lot of people will be having to pay for them :(

[CHRIS ELLIS]

How much are these sensors to buy? Because when warranty runs out it looks like a lot of people will be having to pay for them :(

That will be me then :eek: warrenty ran out october theres no problems thou even if it comes on every time in the morning (guess whos looking forward to the summer without that beeping noise going off 12 times .

[Fasterbaby]

:( yeah you and the rest of us eventually! I suppose we can use the 1 year guarantee for parts but really it should be sorted if it is a known fault! Has anyone actually priced this part up?