heater blows cold on idlew

[gumby80 0]

Hi guys,

 

I was wondering if someone might b able help?

 

I recently bought a g60 and have carried out alot of work:

 

Charger rebuild,stg4, chip n pulley

Pipewerx decat and full system

Full service,cap leads arm plugs,cotton air filter etc...

Cambelt

 

Happy days,youd think. Since i bought the car it has taken a long time to get the water hot and as soon as i hit m/way speeds it cools right down again.simple case of a missing thermostat, i replaced this with a genuine vw one at weekend.i ran car up to temp with heater pointing to hot,all went well. It now reaches operating temp nice and quickly and stays hot on the m/way. My problem is i only get heat from the heater if im driving,ie not at idle.even if i start it from cold and run to temp without moving it blows cold.as soon as i give it some rpm along comes the warm stuff.same if i stop in traffic it goes cold despite the gauge and water being hot.it also appears to have had a new waterpump fitted prior to me buying it.

Any ideas greatly appreciated

[Supercharged 2]

This will be the bypass vales in the engine bay kicking in - maybe heater matrix is leaking

[skinnyman9000 0]

As above really.

 

My advice is to check the matrix first, if it's not leaking then just swap the bypass valves for straight pipes, you can get these from your local vw parts centre as they don't sell the bypass valves anymore.

 

I had the same issue past winter and it was the valves sticking

[gumby80 0]

Brilliant,thanks guys,i dont think my matrix is leaking as i dont appear to losing any water and my carpets are dry,apart from all the bloody snow melting when i do eventually get someheat in there,lol. Now u mention it think i had a similar problem with a mk2 golf years n years ago,at the time i cut down the wifes brush handle and used that,think ill try the vw route this time.

 

Thanks again

[dannyboy 0]

bypass valve goosed,changed mine two weeks ago as it was excat same as yours (found one off a golf,same part number) and now.... lovely red-hot heat

Found the internalls had collapsed slighty restricting flow(but not stopping it)Mine would blow warmish air on 1,colder on 2 and 3+4 was just straight in

[gumby80 0]

Nice,cheers buddy.

Anyone know why they're there in the 1st place? I assume its like a thermostat or pressure regulator? Jus wanna make sure im not gonna have issues if i remove them

[dannyboy 0]

safety device,it is supposed to protect the passagers foot from getting scoulded by hot coolant should the heater matrix fail.pressure difference closes it in the event it does blow out