Aux Heater

[tona955]

Hi All,

 

Very new to this forum..

 

I have a VW Sharan TDi Year 2002 Engine code:AUY Gearbox:EHH

 

Due to the extended delay in heating up the cabin I decided to service the AUX heater and other things, The glow plug tested OK some of the soft gaskets within the AUX Heater were perished so they were replaced with VW original parts, also removed the chamber and cleaned it all, its is ready to install back tomorrow.

 

I replaced the stat and all relevant gaskets/O Rings, currently bypassed the AUX heater pipework to get the car started......in order to test

 

Still taking a long time to produce good heat, if I let it idle it would take days, I kept the revs up to 2.5 and got it up to 90 Degrees mark, would not go any further than that, hot air was there but I expected hotter, upon checking the bottom hose coming from the stat housing it was cold indicating that the stat had not opened.

 

If I then let the car idle with the heater blower full on the temp needle actually cools down, I stuck a bit of tape on one of the cooling fans and it does come on.

 

Question is, is it normal for the temp gauge needle to go cool when idling? the circulating pump is working fine also.

 

The cylinder head was replaced last summer with new gaskets and other than the heating issue the car runs great.

 

I would really appreciate some help with this.

 

Many thanks in advance.

[Dave-G]

If your Gal has done over 75/80K then chances are the auxiliary water pump has it's brushes worn out. The 12v water pump is commonly known as an 'after run pump' because it runs for about 90 seconds after the engine is turned off, which is about the same length of time you hear the 'turbo noise from your heater fan. It could be that the run on's are both governed by the same timer device. :lol:

 

Search for 'after run' on here or google it. The pump will be located just below the dummy bulkhead behind the fuel filter if you fancy a feel -_- to see if it's running. If you switch the engine off in a quiet location you should hear it humming behind the dash. If it doesn't run you will need to replace the brushes - with the spare time patience and tenacity of a saint or replace the pump for about a ton if you need to do a quick and easy fix.

 

The pump is also used to circulate water to your aux heater - if it doesn't run you won't pump engine coolant back to the heater to circulate the 300 or so degrees of piping hot water away, so the heater shuts down.

 

EDIT:I made a right pigs ear of a repair job on mine, it's currently got gaffar tape all over to cover the butchered casing so would like a spare pump that I can replace the brushes at a more relaxed pace - if anyone has replaced their's I'd love to pay the postage for it to be sent to me please.

Edited December 17, 2010 by Dave-G

[Mirez]

Hi and welcome to the forum, it is indeed normal for most diesel engines to produce little waste heat on idle - the aux heater is there to overcome this issue but with it not working, ambient temperatures below 6 and a high heat requirement by the user then its not that strange to see the temperture starting to drop when idling only.

[zorgman]

agree with miraz

you deffo need the aux heater on to get the cabin warm and the first heater the aux heats up is the rear heater, even in summer i struggle to get my car up to 80deg to do timing check so have to use aux booster heater to get temp up, less heat in cooling system means that the engine is working proper as the heat made by combustion is getting turned into power not waste heat

[tona955]

Hi All,

Many thanks for the help.

 

Well, tho it was -6 out there I decided to install the Aux heater, it didn't fireup first time, I checked and cleared all fault codes, also removed the fuel measuring gizmo and gave it a clean.

 

Next start and it all came to life, car heated up is about 5 minutes..WOW....picked up the kids from school and they were complaining about the heat....can't win eh!but am liking the jet engine sound.

 

Only issue is that the radiator bottom pipe is still always cold especially at the thermostat housing side, I just took a trip down to Edinburgh and back about 60 mile round trip but that hose was still cold, could this be a block in the radiator?

 

All in all it was worth all the work, no more smoke or smells in the cabin, I am actually turning the heat down this time.

 

Next job, getting the speedo and fuel gauge working....I'll be back....

 

Many thanks once again for all the support..

[zorgman]

check the earth on the multi plug traced mine to a faulty earth there when my speedo went off go for the brown ones give a tug to check

[tona955]

Hi

 

Many thanks Zorgman, I have started another post for this issue but will check the poor earth issue tomorrow.

 

Cheers