[Mike from Oz]

Hi, Has anyone had this happen, Temp rises after startup then will drop to 60 and up and down, this is slow and random. Also very little heat coming from vents but I believe this could be the mixer motor and not related. Scanned with Multiecuscan and correct plugs but no faults showing, I can manually operate and set all actuators on heating system but there is nothing for the mixing motor.
Can anyone help with this.

 

[bazzbazz]

Thermostat stuck open springs to mind. Does the temperature show on MES correlate to what the gauge shows?

As for the heater mixer flaps have you run the "Flap Actuators learning" operation in MES?

 

[Mike from Oz]

Thanks Baz, When I have MES connected you see temp rise and needle on gauge goes to 90 and stays there, temp goes up and down 70 to 96 so I have to assume the thermostat is working, I have done Flap actuator learning and can hear them all go through open/close process.
1 While I can force actuators in MES can I force the coolant valve, I have heard they can fail or linkage fails.
2 Can a faulty temp sensor cause all this.
3 Do you do callouts to Melbourne ( joking ) or can recommend anyone down here, I know of most service people but having done most repairs myself haven't used many,
Mike

 

[bazzbazz]

I don't really believe in co-incidences, so the fact that your engine temp is varying wildly and your cabin heater is not performing well I would suggest it's most likely a thermostat problem (don't take that as gospel).

Contact Italian Automotive Spares in Brunswick East, they can supply you a new thermostat, and the ones they supply usually come with a new temp sensor included. -

Italian Automotive Spares

 

[Jetronic77]

Temperatures always vary widly, that's why all cars get dummy gauges now. But that's a bit too wildly. That said, you get decent heat from the hvac unit even when the needle hasn't moved from 50°C yet if all is well.

 

[wbanham]

Have you looked in the Climate Control Parameters tab in MES ? Do all the values make sense ? So far you've only mentioned the Actuators and coolant temperature.

 

[Dave Brand]

I don't really believe in co-incidences, so the fact that your engine temp is varying wildly and your cabin heater is not performing well I would suggest it's most likely a thermostat problem (don't take that as gospel).

I'll second that - has all the classic symptoms of a failed thermostat.

 

[Mike from Oz]

Thanks, new thermostat it is, with PS as well so should clear that avenue as well.

While I'm here, have you ever used Molybond Oil Supplement, it's been used by many who swear by it and I used it in my old 147 TS 185Ks . but while I wouldn't use it in our 1.4 or QV engine I'm thinking of my Gearbox which is a bit notchy in gear changes now.

 

[Mike from Oz]

Have you looked in the Climate Control Parameters tab in MES ? Do all the values make sense ? So far you've only mentioned the Actuators and coolant temperature.

Yes, and they don't make sense, can manually actuate via MES and you can hear them operate but get this result when running, see attached.

 

[wbanham]

9.5degs, hard winter then ?

The parameter values sort of make sense, it is directing the heat to the colder side although both sides are well off the requested temp of 31deg.

Would the engine coolant temperature heat up quickly to 90deg if the thermostat was stuck open ?

Have you checked that the heater matrix is heating up ? Air lock, blockage ?

 

[bazzbazz]

I'm thinking of my Gearbox which is a bit notchy in gear changes now.

I would suggest changing the gearbox oil first than using any additives to solve notchy gear selection.

 

[Mike from Oz]

I would suggest changing the gearbox oil first than using any additives to solve notchy gear selection.

I did, using the correct spec oil, Nulon, the old oil was clean and very little fragments on the magnet, if anything I feel the notchy feeling is slightly worse, maybe just imagining that, I have used molybond in engines and the results in an old motor is incredible, heard from FWD extremist that he and others swear by the stuff in gearbox's, but I don't know if the syncro rings will be affected so wanted to know of anybody has done this in a G QV.