Heater Issues

JMO · 15-07-2008, 10:48 AM

Hi guys.

I am currently having some issues with my heater. No heat seems to come out. I've tried every setting but nothing will work. I've also realised that my windows are always fogging up and the only way that i can get rid of it is to use the A/C and even this takes a while to get rid of it off windscreen.

I've checked behind the glove box and the wire thing that changes the temp seems to be working ok.

It's starting to get very annoying, especially on cold nights with no heat and the A/C on.

Anyone have any suggestions as to what it might be? Any help would be greatly appreciated.

InfernoSR · 15-07-2008, 11:21 AM

So your fans are working alright?

I'm thinking its the heater tap... a vacuum line could be off... or its shut closed...

JMO · 15-07-2008, 11:28 AM

Yeah, the fans are working alright. How can i check if the heater tap is working correctly?

InfernoSR · 15-07-2008, 11:42 AM

Quote:

Originally Posted by JMO

Yeah, the fans are working alright. How can i check if the heater tap is working correctly?

Get someone to flick the heater control on and off whilst you watch for movement of the butterfly...

JMO · 15-07-2008, 03:02 PM

I looked at the hater tap while someone was turning the heater control on and off, but couldn't see anything move, but i may be wrong. The only thing is the inlet to the heater core was warm as was the outlet. Does this mean that it is functioning correctly?

InfernoSR · 15-07-2008, 04:01 PM

Quote:

Originally Posted by JMO

I looked at the hater tap while someone was turning the heater control on and off, but couldn't see anything move, but i may be wrong. The only thing is the inlet to the heater core was warm as was the outlet. Does this mean that it is functioning correctly?

Depends on how hot it is... you shouldnt be able to touch the pipes when at full operating temperature...

JMO · 15-07-2008, 04:33 PM

I took the car for a spin to bring it up to operating temperature and the pipes are about the same temperature as the upper radiator hose, maybe just slightly under. What i did discover was that there was a whistling coming from somewhere in the vents while traveling at 70km/h and less frequently at lower speeds with the fans on high.

Am i right to assume that there is a vacuum leak somewhere?

InfernoSR · 15-07-2008, 04:58 PM

Quote:

Originally Posted by JMO

Am i right to assume that there is a vacuum leak somewhere?

Try driving with the glovebox removed and listen for whistling from there...

sly · 16-07-2008, 06:23 PM

Quote:

Originally Posted by JMO

my windows are always fogging up and the only way that i can get rid of it is to use the A/C and even this takes a while to get rid of it off windscreen.

Sounds like a clogged or leaking core. Lift passenger side cfarpet and kook for coolant on firewall / floor. Does the car have a funny smell in it when you put the demister on? Like dogshtt?

Check % double-check everything else first. A core is pretty cheap but a big job to change.

JMO · 17-07-2008, 11:18 AM

Took the ar for a drive today, with the glove box off, but i could not hear the whistling noise i heard the other day.

There is also no smell in the car (which I'm assuming would be quite strong) with the demister turned on and no wet carpet on the passenger side.

If the heater core is clogged what would be the best way of unclogging it?

sly · 17-07-2008, 06:08 PM

Quote:

Originally Posted by JMO

There is also no smell in the car (which I'm assuming would be quite strong) with the demister turned on and no wet carpet on the passenger side.

No smell is a good start, but the bit about taking a long time to clear the screen even with the AC on rings a loud bell for me.

There is 20mm or more of dense, sound-absorbing foam bonded to the back of the carpet. It holds a LOT of water and the glue acts as a barrier keeping the water out of the carpet for a long time. I didn't get damp patches on my carpet for months of putting up with it, thinking my aircon was bodgy and too broke at the time to be game to have the aircon looked at.

To rule the heater core out, you need to peel back enough of the carpet from the firewall to get a good look at the foam and the firewall itself. You probably need to remove some of the door seal from the lower A-pillar (maybe the scuff plate as well?) to peel back the carpet over the PCM to get a good enough look.

Any drips/dribbles of coolant down the firewall or discolouration of the foam will be obvious. Just don't trust the dry carpet.

InfernoSR · 17-07-2008, 11:49 AM

The "best" way to unclog a heater core, is to remove it and have a specialist rod it out... but a good alternative and DIY version is to flush it out with an additive... look for my DIY guide to DIY system flushes...

JMO · 17-07-2008, 06:15 PM

Thanks for the help so far everyone. I'll have a good look under the carpet tomorrow.