GolfGTIforum.co.uk

Model specific boards => Golf mk3 => Topic started by: 1 gti on 28 June 2012, 23:49

Title: Mk3 heater temperature control
Post by: 1 gti on 28 June 2012, 23:49
My temperature control is stuck on hot!! Not good when it's 20c, lol. Fan speed and direction still works normal. Taken the unit out and the temperature wheel just turns but cables don't move. What's the possible causes? Cable come off on the flap end? Any help would be appreciated. Cheers
Title: Re: Mk3 heater temperature control
Post by: Wayne on 29 June 2012, 00:10
I guess the cable has come off, cannot see it being much else.

Is the engine temp all ok.
Title: Re: Mk3 heater temperature control
Post by: 1 gti on 29 June 2012, 09:33
Engine temp doesn't go past 70. Doesn't over heat or anything though. That's most prob temperature sensor
Title: Re: Mk3 heater temperature control
Post by: thai-wronghorse on 29 June 2012, 09:36
Sounds like you need a thermostat for starters as the temp gauge should sit at 90 once the engine is warmed up.
Title: Re: Mk3 heater temperature control
Post by: 1 gti on 29 June 2012, 09:38
Thermostat? That's the temperature sensor right?
Title: Re: Mk3 heater temperature control
Post by: thai-wronghorse on 29 June 2012, 09:44
No, its a temperature sensitive valve that sits beneath a plastic housing on the side of the water pump.
Title: Re: Mk3 heater temperature control
Post by: javalin on 29 June 2012, 09:45
No seperate bits, temp sensor does what it says, and thermostat regulates the engine water temp to 90c by directing coolant out to the radiator as needed.

If it comes up to 90c when standing, then thermostat needed.
Title: Re: Mk3 heater temperature control
Post by: 1 gti on 29 June 2012, 15:47
Doesn't over heat. When driving and ticking over it stays at 70 and no higher. Going to change thermostat and see what happens. I think it's heavy on diesel too
Title: Re: Mk3 heater temperature control
Post by: thai-wronghorse on 29 June 2012, 15:50
Engines generally overfuel when they don't reach optimum running temperatures as they over compensate with open chokes, cold start valves etc.
Title: Re: Mk3 heater temperature control
Post by: 1 gti on 29 June 2012, 16:45
Hope the thermostat is at fault then  :smiley:
Title: Re: Mk3 heater temperature control
Post by: 1 gti on 29 June 2012, 18:53
NEWS!!! New thermostat fitted and went for a spin to test and all was well until the needle reached 100c!! No fan coming on, no over heating and Water in the expansion tank weren't bubbling and the engine feels the normal temperature. Dodgy needle in the dash? any help would be appreciated before I decide to torch it!! Lol. Must remind you it's a diesel if it makes a difference. Cheers
Title: Re: Mk3 heater temperature control
Post by: Deano2711 on 29 June 2012, 19:49
Temp sender ??
Title: Re: Mk3 heater temperature control
Post by: Wayne on 29 June 2012, 23:57
As Deano said, replace the temp sender.
Title: Re: Mk3 heater temperature control
Post by: thai-wronghorse on 30 June 2012, 00:08
Air lock maybe?
Title: Re: Mk3 heater temperature control
Post by: 1 gti on 30 June 2012, 14:50
Went out this morning and the needle was on 70 and overheated on me, flashing light on dash. Free car anybody? Where's the temp sender located? Cheers
Title: Re: Mk3 heater temperature control
Post by: Deano2711 on 30 June 2012, 18:16
Located at the top right hand corner of the front of the block. The top hose goes to it and it will be a coloured part. Let the car cool down beforw changing and its a two minute job to change.
Title: Re: Mk3 heater temperature control
Post by: Wayne on 30 June 2012, 23:44
Went out this morning and the needle was on 70 and overheated on me, flashing light on dash. Free car anybody? Where's the temp sender located? Cheers

Sounds like to me that it has an air lock.
Title: Re: Mk3 heater temperature control
Post by: thai-wronghorse on 01 July 2012, 01:01
That's what i reckon as well.
Title: Re: Mk3 heater temperature control
Post by: Gavv8 on 01 July 2012, 09:30
Try running it from cold with the heater on full and the cap off the expansion tank, keep squeezing all the hoses to get the air out until the engine starts to warm up then put the expansion cap back on but keep the heater on full and keep your fingers away from the cooling fan in case it comes on suddenly.
Title: Re: Mk3 heater temperature control
Post by: 1 gti on 02 July 2012, 13:33
Overheated on Saturday and the radiator was stone cold, just bought new waterpump. Hope this works, nothing but bad luck last week. Keep you posted  :smiley:
Title: Re: Mk3 heater temperature control
Post by: thai-wronghorse on 02 July 2012, 13:41
Still sounds like an airlock or dodgy thermostat.