Heater Blowing Only Cold Air

[Carlc]

Hi,

 

Sorry all, I know you guys must be sick of people like me joining and asking stupid questions.

 

I would like to know where to start in fixing myself (xmas round the corner - cant be paying a garrage) my cars heater.

 

I have a 2001 Seat Alhambra 1.9TDI Auto.

 

Over the last week the heating has been fading. Only seemed to blow any heat if i was doing over 60 on the motorway. When i slow down or stop at a junction, the heat would just turn cold. However, since yesturday I have had no heat what so ever. No matter what setting or fan speed i put it on, its always cold.

 

All the buttons seem to do their job, fan speed etc.. however just the temp doesnt chance. Same for the rear heaters too.

 

I have only gone as far as looking at the fuses and all "seem" ok.

 

 

Any ideas where to start??? Thanks All

[davewill]

Lots of people say air locks in pipes, but i say Water Pump and Impellor falling off

 

If it is the Impelloor, you will get overheating of the car within a few days

[chrispb123456]

Hi,

 

Sorry all, I know you guys must be sick of people like me joining and asking stupid questions.

 

I would like to know where to start in fixing myself (xmas round the corner - cant be paying a garrage) my cars heater.

 

I have a 2001 Seat Alhambra 1.9TDI Auto.

 

Over the last week the heating has been fading. Only seemed to blow any heat if i was doing over 60 on the motorway. When i slow down or stop at a junction, the heat would just turn cold. However, since yesturday I have had no heat what so ever. No matter what setting or fan speed i put it on, its always cold.

 

All the buttons seem to do their job, fan speed etc.. however just the temp doesnt chance. Same for the rear heaters too.

 

I have only gone as far as looking at the fuses and all "seem" ok.

 

 

Any ideas where to start??? Thanks All

First of all check coolant level? has the level gone down? there have been instances where water pumps have failed but you would surely be overheating if doing motorway driving.

The cooling system is self bleeding providing water pump and run on pump are working correctly.

Is the booster heater still working or is that dead?

[Carlc]

Hi,

 

Sorry all, I know you guys must be sick of people like me joining and asking stupid questions.

 

I would like to know where to start in fixing myself (xmas round the corner - cant be paying a garrage) my cars heater.

 

I have a 2001 Seat Alhambra 1.9TDI Auto.

 

Over the last week the heating has been fading. Only seemed to blow any heat if i was doing over 60 on the motorway. When i slow down or stop at a junction, the heat would just turn cold. However, since yesturday I have had no heat what so ever. No matter what setting or fan speed i put it on, its always cold.

 

All the buttons seem to do their job, fan speed etc.. however just the temp doesnt chance. Same for the rear heaters too.

 

I have only gone as far as looking at the fuses and all "seem" ok.

 

 

Any ideas where to start??? Thanks All

First of all check coolant level? has the level gone down? there have been instances where water pumps have failed but you would surely be overheating if doing motorway driving.

The cooling system is self bleeding providing water pump and run on pump are working correctly.

Is the booster heater still working or is that dead?

 

 

I have no idea what "booster heater" is. sorry.

 

There is no signs of overheating at all. The water temp are 100% normal. I know that the gearbox oil is water cooled and that temp is normal too.

 

I let the car stand for an hour or so after getting to work, then took the expansion tank lid off. There still was a lot of pressure in it. needless to say a fair bit of water came out. I will check the level of that again before I set off home.

[Higs]

I have these symptoms too:

 

• heater only blows cold air even when engine temp displays 90c
  
• coolant level drops when engine running
  
• pressure in expansion chamber even after cold for many hours (days!) - coolant returns when pressure released
  

 

To date this has been an annoyance but not a real problem. However we've had a couple of overheating incidents recently and I reckon there must be a link.

 

Garage has replaced thermostat, reverse flushed coolant system and tested coolant for exhaust gases (negative). Water pump has been replaced - impellor was free from shaft.

 

In the past the aux heater has been either bypassed or blocked off by a different garage - I don't actually know what they've done as (i) my wife took it in for something else and they just did it for her (without asking) as it was smoking and (ii) because of where I live/park I can't really get under the car to look and wouldn't know what to look for if I did.

 

Since the car last went into the garage I've read on here about a 'run on' pump. As far as I can tell this second pump is not running - certainly there's no notable 'whirring' under the bonnet once the engines off. In fact thinking about it the fans behind the radiator never seem to come on either.

 

 

1.9TDI '02 reg 130,000miles.

 

Any ideas?

 

The guy at the garage (who I trust after many years of good service and common-sense advice) says it has some of the symptoms of a CHG failure, particularly the pressurisation, but he's confused by the absence of combustion product in the coolant. He says he's happily do the gasket for me but can't be sure that's the fault.

 

The garage is closed now 'til Jan 4th and our other car (Saab) is refusing to start. Joy.