Climate control/heating fault

[Sheriff]

Hi all, my car seems to have developed a fault in the last few days.

I have the heating set at 20 degrees and the climate control on auto. Engine temperature seems steady at 90 degrees when warm. I now find that on longer journeys the climate control varies from blowing hot to cold air and the fan speed seems to go up and down without changing any settings.

Please can anyone advise is this likely to be related to climate control/air con system or is it an early warning on head gasket going ??

All fluid levels seem fine and there's no oil in the water or vice versa.

[Russ_vRS]

With it set on auto it will keep the cabin at the set temperature. So if it get warmer it will blow cold air and hot air when it gets colder.

[Sheriff]

Thanks for the reply Russ. Maybe it's just the current weather with being cold at night and getting warmer inside the car during the day with the sun. I've not known do this before though and I've had it nearly 3.5 years now.

[Geordie John]

My airco starts blowing cold when set at say 21 or 22 after about 40 mins driving. The dealer reckons it's the sensors in the foot wells and has ordered me new ones. We'll have to see if it works.....fingers crossed.

[steveo82]

I posted a fault on mine sort of similiar to this, one side will be chilled at 16c and other says 16c but is warm and gets quite hot after 10-15 mins, are these sensors expensive and how big/little of a job to fit??

Just a thought but can floor mats or other obstructions cause false readings to these thus causing this kind of fault??

Edited 26 April, 2013 by steveo82

[Sheriff]

Thanks for the responses. Has been ok for the past few weeks but just been the usual work/local ish runs. Off to a christening in London tomorrow for the day so will see how it goes on another long journey

[pipsyp]

It will vary the air temp depending on the current interior temperature (circular sensor on front of climatronic panel) and also depending on whether it can sense any potential solar heat from direct sunlight (via sensor on dashboard by windscreen). The temperature going hot and cold randomly is entirely normal and how the system works to maintain temperature.

On Auto it will vary the fan speed to work to get to the desired temperature as soon as possible, on the FL model there is two Auto modes, 1st allows variable fan speed but restricts it to the first 3/4 speeds of the 7 so fan noise doesnt become excessive, 2nd Auto allows full fan speed (useful for a really hot day I guess).

I have found on mine on Manual mode that it will occasionally start up with a slightly increased fan speed than what i have set, wonder if perhaps the solar sensor or temp in the car at the time of start up causes it.

I dont use Auto mode hardly ever, normally just set mine to 20/21 degrees on 1st fan speed and distribute the air out of the windscreen and floor vents as unless its really hot dont particularly enjoy air blown in my face.

Having not had a car long term with full climate control have to say it is quite an impressive system in the Octavia and very much set and forget most of the time. In my old Fabia vRS with manual AC was forever tweaking the temp dial.