Poor Hot Air

[madocks]

OK, the wife is complaining her car is cold. I have done the following;

 

Checked fuses - all ok

Checked aux heater - hot as foook!

Checked water level - Was below the min level so topped up

 

When I set the temp to LOW and Motors to Max theres loads of air comming through the vents. Front and rear.

When I set the temp to 18, the amount of air that comes through the vents is approx half.

When I set temp to high, the amount of air is still crap and its not very warm at all.

 

Car also takes ages to warm up, perhaps linked?

[madocks]

Update, just checked the run on pump, took it out and placed it in a bucket with 12v accross it. Nothing pumped...........

 

Stripped the top off, impellor seems fine. Plastic, put 12v across it with just impeller and it spins. However not very fast. Am I to assume Run on pump broken?

[madocks]

Update 2: put every thing back together, when i turn ignition on I hear a whiring noise. No water trickles into the expansion tank. Have ordered a replacement motor.

[SilverBeast]

Worn motor brushes on pump. See here for replacement instructions.  They seem to wear out at about 80k ish.  

[madocks]

Worn motor brushes on pump. See here for replacement instructions.  They seem to wear out at about 80k ish.  

 

Nope, new pump installed. Seems i wasnt testing the pump in the water correctly. Have better hot air in front and no hot air in back. Is that the aux motor?

[BrianH]

If your getting no water returned to the header tank thats usually a sign of the water pump impeller coming off its spindle (the one driven by the engine, not the run on pump). Theres been various posts about this, i think you can test this by removing something and poking the impeller with a screwdriver (it shouldn't move - if it does then its not connected to the spindle inside and needs to be replaced - various posts here from others who've had it happen). Though I'd expect to see some signs of overheating in this circumstance.

 

You may have ended up tripping out the aux heater if its overheated if your getting nothing in the back, its a case of looking at vcds to reset it/check whats wrong.

 

The other possibility is that the thermostat is stuck open allowing flow through the radiator at all times - you'd usually notice this by it being cold only when your moving through traffic, with rising temp when stationary.

 

Any idea where the water that went missing appeared to go to?

[madocks]

Water is trickling into expansion tank so not the water pump.

 

Front heaters work but not back heaters, and air flow is quite poor out of back heaters.

 

Aux fires up and gets very hot, so thats working.

 

Missing water was from 12 months, not a huge issue loosing a small amount. she just never tops her car up

[BrianH]

first thing then check the hoses under the car towards the rear heater - if these are hot, then its probably a flap inside the heater unit in the wrong position (either its broken, come away from the operating mechanism, or been set to the wrong position on the controls).

 

Given the aux heater you say fires up, this would suggest its not water related more likely related to the flaps ending up in the wrong position.

 

There isn't any pollen filters on the back heater, so that won't be the issue. It might be worth taking the rear cover off and having a look at whats going on there - does the sound of the motor change when you alter the rear controls or does it seem always on the same setting?

[madocks]

first thing then check the hoses under the car towards the rear heater - if these are hot, then its probably a flap inside the heater unit in the wrong position (either its broken, come away from the operating mechanism, or been set to the wrong position on the controls).

 

Given the aux heater you say fires up, this would suggest its not water related more likely related to the flaps ending up in the wrong position.

 

There isn't any pollen filters on the back heater, so that won't be the issue. It might be worth taking the rear cover off and having a look at whats going on there - does the sound of the motor change when you alter the rear controls or does it seem always on the same setting?

 

BLower can be heared and it increases in speed with the fan control on Dash

 

Ill check the hoses when its not raining cats and dogs, any other checks I can do in this weather?

 

I also have this vagcom error -

 

 

Address 18: Aux. Heat Labels: 7M3-815-071.clb

Part No: 7M3 815 071 C

Component: HEIZG. B/D5W 0001

VCID: 30692E2AF0CA94BEC1-5160

 

5 Faults Found:

65535 - Internal Control Module Memory Error

00-00 - -

65535 - Internal Control Module Memory Error

00-00 - -

65535 - Internal Control Module Memory Error

00-00 - -

65535 - Internal Control Module Memory Error

00-00 - -

65535 - Internal Control Module Memory Error

00-00 - -

[BrianH]

suggests to me either the intake is blocked, or the flaps aren't being set in the right position. You could remove the inside panel and have a look? I think you can access the hoses from there as well, not sure offhand without looking.

 

Not sure on the vagcom errors, Are you using vagcom or vcds lite? I'd try clearing them and see if they come back, sounds like they are errors that don't have a proper definition, but if your using vagcom it may be fixed by using the more upto date vcds instead.

[madocks]

Using the latest VCDS with a proper lead, not an ebay lead.

 

Aux heater has stopped firing up, wierd!

 

Pipes in and out of heater are luke warm, so im assuming thats the warmth comming from the front heater matrix.

 

If the aux unit isnt working then the flaps / motor wont be working either.

 

I took the wiring plug appart earlier, was all manky, sprayed with contact cleaner, reset errors and still the same. What temperature does the aux heater start working at?

[BrianH]

Depends on your model - I think its 10 degrees on the mk2, 5 degrees on the mk1. Think you've got a mk2 from whats been said about the aux pump?

 

Manky connector isn't going to help, though you'd need one of the aux heater wizards on here to know whats going on with it if its not that.

 

The connector has been problematic in the past, I think I've seen people post about having to fix it (bypassing the connector with soldered connections seems to come to mind) This might explain your odd error codes if the connections to it are dodgy.

[madocks]

Depends on your model - I think its 10 degrees on the mk2, 5 degrees on the mk1. Think you've got a mk2 from whats been said about the aux pump?

 

Manky connector isn't going to help, though you'd need one of the aux heater wizards on here to know whats going on with it if its not that.

 

The connector has been problematic in the past, I think I've seen people post about having to fix it (bypassing the connector with soldered connections seems to come to mind) This might explain your odd error codes if the connections to it are dodgy.

 

Thanks for your help, are you able to tag the aux gurus into this topic?

[SilverBeast]

The good news is you appear to have the older model of the 5kW Auxilliary (B/D5W) which doesn't seem to be  as prone to controller failure as the newer D5Z-F.

 

Can you confirm the model, it's on the label on the heater. Or provide the year of your car, I think they switched in 2004/2005 to the newer one.

 

Have you read the big thread (29 pages!) on auxilliary/booster heaters?  I seem to recall some have been prone to failure of the power feed to the heater.  From memory it's a large red wire but I can't recall if it fails on the car side of the plug or on the wire between the connector and the heater.  I'm not even sure if it's in that thread or one of the (many) others on this site or the other one.

 

I believe the VAG-COM error is a pretty generic error for controller problems, but I'd expect these if the controller was getting an intermittent or low power feed.  I think this thread has a download of Booster Heater information for the earlier model, with pinouts.  It would be useful to see if you can measure the supply voltage to the heater if possible as that may indicate defective wiring.

 

Does your fan come on on the booster heater, as this runs up to speed first if I recall to get the air flowing, before turning on the glow plug and then injecting the diesel to "fire it up".  Easiest way to tell if the heater is functioning is the heater exhaust gets hot and you can feel/see hot exhaust from it, being careful not to burn yourself of course!

 

Good luck

[madocks]

Update:

Air comming out of boot is loads - and nice and hot
Air comming from head lining is poor and cold
Air comming from behind front chairs is poor and cold
Air comming from dash is poor and warm

When cold the aux heater fires up, and the exhaust is very hot to touch.

Car still smells of fumes, today its stinking of fumes but the Aux heater isnt even on.

[xavier]

When you have the blowers up full, does it sound like an athsmatic trying to run for a bus? Could just be you need to change the pollen filter.