2007 VE V series Intermittent Overheat

[MickS]

I have a weird problem with the wife's car with intermittent overheat. I took it to my local Holden dealer and they could not find anything wrong; obviously it was not in fail mode at the time. If anyone has suggestions I would appreciate some advice. Here are the symptoms I described to the dealer:

When the aircon is ON, the recycle/recirc light comes ON also, regardless of where the switch setting is; ie the setting is on face or face and floor and the Recycle light is ON.
Attempts to turn the recyle OFF, the light goes off immediately and then comes back ON by itself. Pressing it to OFF again has the same result. After several attempts of this the recycle light Flashed a few times and then went back ON BY ITSELF.
When the aircon is turned off the recycle light also goes out (as normal I expect).
At one stage I could get it to work properly, ie aircon ON with recycle OFF, but then it happened again as per above.
Additionally, the engine temperature is getting too high, ie just under the H, when it normally runs at one notch under half. The engine fan comes on at about the half mark and when the engine is shut down the fan continues to run (as normal). I also heard a click from under the bonnet at some point after the engine was shut down (thermostat?).
I am unsure as to whether the aircon issue is related to the overheating, when I drove the car around my suburb, early on the temp was rising so I turned the aircon OFF and the temp went back down. Later in the trip the temp kept rising even with the aircon OFF. The temp got to one notch below H.

This has come on this week when the wife drove home from work (about 7 klms).
What could cause the recycle to come on by itself?
Does the cooling system, ie getting hot, somehow cause the recycle to come on?
Is the recycle connected somehow to the engine cooling?
Is it a thermostat failure causing the overheating, ie a sticky thermostat? The water level has been checked and is OK.

With summer coming on this could be a problem.
I understand that the dealer tech can only test what is happening when they have the car; if it is not in fail mode then they will not be able to track the problem. After I picked it up from the dealer eysterday I drove it around for 90 minute and all worked fine.
But obviously something is wrong somewhere; I don't know what triggers the fail.
Does the overheat cause the aircon problems or does the aircon problem cause the overheat.

I am tempted to replace the thermostat anyway.

Any advice is welcome and thanks in advance.

Cheers,
Mick

[RiCeY]

Very unlikely to be the thermostat, im yet to see one fail and ive been with holden several years. Are you checking the water level at the cap or the overflow bottle? The cap may have failed and the valve may not be operating correctly.

As for the recirc ensure the front demister button isnt pressed. Failing that the recirc flap may be jammed. Raise the bonnet and on the passenger side along the base of the windscreen you will see push clips along the plastic trim. Remove the rubber seal and the clips and lift the top part of the plastic up and you can look down into the intake which is covered by a leaf filter. You may need a torch. Get someone to turn recirc on and off and see if the flap is opening and closing. Might need to pull the leaf filter out to see properly. If it looks like its stuck it will require a new flap.

[MickS]

Thanks for your input RiCey.
The Holden dealer checked the full system; software, HVAC?, water levels etc and advised that everything was fine. They said they spent some time on the car testing all including driving but could not fault the system. They advised that they need to see it while it is in fail mode.
With regard to the recirc I check the recirc flap and it works fine as I expected because the recirc distinctly redirects the air when it works properly; you can hear and feel it. The button does not get stuck in either.
When the problem presents, it automatically turns the recirc on and it cannot be turned off as described in my orig post.
Again, I am unsure what triggers the problem - whether the engine getting hot (over half) causes the recirc issue, or the recirc issue causing the overheat.
At this point we are monitoring it so that when and if it fails again we can get down to the dealer so they can diagnose it in the fail mode.

Cheers,
Mick

[RiCeY]

May be a long shot but try this, pollution mode may be set to ON.

The system can be set to pollution mode which selects recirculation when the vehicle speed is less than 15 km/h. This helps to prevent exhaust fumes entering the interior in heavy, stop/start traffic. To switch pollution mode on or off, press and hold the recirculation button for four seconds. When pollution mode is activated, the display shows Pollution Mode Activated. When it is switched off, the display shows Pollution Mode Inactive.

[Gravity]

Wow Ricey, I'd not even heard of that.