Strange heater problem

[Nightscape]

Have done a search but nothing conclusive. Got a weird problem on my 2002 PD130. When driving along, after the car has heated up, the heaters blow plenty of hot air as you would expect. However when you stop the car, and have it just idling the air gets colder until its blowing cold air!

My VAG techie pal thinks it could just be as simple as an air lock in the rad? Im hoping its not the pump, as the previous owner apparntly just changed it!

Anyone had a similar problem?

 

[krussel]

Not had this with the SEAT but seen it a few times before and normally a heater blowing hot then cold means an airlock.
Guess when you stop driving it becomes stuck in the heater matrix. Either way the system need to be bleed of all air to make sure before you start thinking of new pumps.

As the pumps been changed already it was prob not filled correctly to remove the air. Not sure on the Ibiza but most cars have a bleed valve which needs to be open when refilling.

 

[Nightscape]

Not had this with the SEAT but seen it a few times before and normally a heater blowing hot then cold means an airlock.
Guess when you stop driving it becomes stuck in the heater matrix. Either way the system need to be bleed of all air to make sure before you start thinking of new pumps.

As the pumps been changed already it was prob not filled correctly to remove the air. Not sure on the Ibiza but most cars have a bleed valve which needs to be open when refilling.

Thanks Krussel, that seems to be what everyone else is saying. Logging the cars temp, its not overheating or anything
If anyone can give some tips on bleeding an ibiza, would be most welcome. If not ill bluff through it tommorow

 

[cupraajy]

Plenty of coolant in the resviour??

 

[mgrays]

The Furbies (Fabia) have a thermocouple that dies on the heating matrix. This sets the temp of the heater output. Trouble is you have to break it to remove it .. so you cannot test it insitu. Mine certainly gets cool when standing like you describe .. not really cool but certainly noticeable. I think my thermocouple is on the way out as I have to set the climate control higher by 2-3 C than you would think..

I presume the fan speed is blowing.. and it is not just a duff fan and at speed the ram air effect is blowing the air through the heater matrix?

 

[Nightscape]

Plenty of coolant in the resviour??

Yeah, been keeping an eye on it, it goes up and down

The Furbies (Fabia) have a thermocouple that dies on the heating matrix. This sets the temp of the heater output. Trouble is you have to break it to remove it .. so you cannot test it insitu. Mine certainly gets cool when standing like you describe .. not really cool but certainly noticeable. I think my thermocouple is on the way out as I have to set the climate control higher by 2-3 C than you would think..

I presume the fan speed is blowing.. and it is not just a duff fan and at speed the ram air effect is blowing the air through the heater matrix?

Yeah fan can be turned up max when sitting...

 

[myneek]

What temp is the car saying the coolent is at? Guessing you've got VAGCOM plugged in?

 

[cupraajy]

I just know from past experience with my old cupra...u suffered the same problems and was down to a coolant leak, worth checking the coolant level with the engine switched off, as when it is on the water pump etc will be running.

 

[Nightscape]

What temp is the car saying the coolent is at? Guessing you've got VAGCOM plugged in?

Ive got VAGcom but havent started using it yet, im currently just using the scangauge from my MINI. When the car has heated up it sits around 85* and 90*C. Which seems pretty normal.

I just know from past experience with my old cupra...u suffered the same problems and was down to a coolant leak, worth checking the coolant level with the engine switched off, as when it is on the water pump etc will be running.

When the engine is off, the coolant is about the max mark. The system is holding pressure, as it gushes steam/air when opened. After opening the coolant level drops before your eyes

Im gonna try draning it today, and refilling.

 

[cupraajy]

Mine did the exact same thing...also noticed that when driving the temp sat a constant 90 on dials but when stuck in traffic it creeped up!
Worth topping up or changin the coolant as u suggested.

Mine ended up being a water pump, seal had gone somewhere hence the loss in coolant! i had other symtoms aswell so shouldnt worry too much about that!

 

[Nightscape]

Ok water pump and cambelt changed yesterday. Heating does seem to be better, however we noticed the radiator would not heat up. So now thinking thermostat. Also noticed now a drip from the plastic undertray, could just be residual stuff that was sitting there. But if its a leak ive no idea where its coming from.

 

[Nath.]

My first thought when I read the first post was a stuck open thermostat.

 

[Nightscape]

Im hoping the thermostat solves it, if not ill have to start thinking head gasket

Car is quite hard to start first thing, i just put it down to the cold weather...

 

[Nightscape]

Thermostat changed, rad now gets hot, scangauge shows the engine sitting between 87- 91 *C which is perfect. However car heating is still not great. Sometimes its roasting. Sometimes its cool. Now when you stop, it sometimes stays hot, others it cools again. I scanned with VAgcom, i have a constant fault with the air flap. Could this be causing my probs

 

[techie]

Yep its the flap for sure.

Have you tried running basic settings on the flap?

 

[Nightscape]

Yep its the flap for sure.

Have you tried running basic settings on the flap?

Yeah my mate ran a diagnostic on the climate control, it did loads of whirring. Passed that though. Everytime you reset the flap fault code though, it comes back after a few minutes. So it defo isnt happy with it!

 

[RUM4MO]

Maybe try whacking the temperature to HOT then COLD quite a few times as it could just be the temperature flapmotor pick-off resistor wiper that is dirty. I did that on my Passat and it worked okay for another summer - but now its back to "hunting". If you keep the temperature up high enough it should still keep the car cabin hot or maybe too hot, but I'd think that its better to suffer that until Spring time, then pull the car to bits and sort it before you start to overheat in Summer as that is just not quite so comfortable!

 

[Nightscape]

Quick update: Ended up changing the head gasket, had the head pressure tested and skimmed. Still no heaters

All i can actually do is laugh. Bed time i think