AUX Heater flame out

[fs123]

The booster heater on my Galaxy tdi 2003 stopped working just in time for winter. I had changed the glow plug last year and it worked fine but sadly failed again this year.

I checked with VAGCOM and there was the flame out code which I cleared. After a while I could hear the blower but couldn't hear the metering pump and nothing else happened and the flame out codes came back. With the VAGCOM output tests I could hear the blower and metering pump as normal.

I ordered new glow plug (Beru GH001) and fitted that yesterday but still the fault remains.
I will check the fuel metering pump for flow but I'm not confident it will be that since the ecu doesn't attempt to start the pump when the blower is audible.

edit: heater is a D5W - Z

Any ideas guys?

[johnnyroper]

What heater is yours? Do you have early type with control unit on end or later type with it on the top?

[bigdave982]

Check fuel level they dont like less than 1/4 tank

[fs123]

Check fuel level they dont like less than 1/4 tank

It's the D5W - Z which takes the Beru GH001 glow plug. I think it's controlled by the ECU but not sure.

[insanitybeard]

It (the glow plug) will be controlled by the booster heater's own ECU for sure, but it sounds like you may have a temperamental dosing pump- due to their exposed position wiring corrosion on the connectors is quite common so I would be checking that out next- the ECU may well be trying to power up the pump but if you've got wiring/ connection issues or a temperamental pump and therefore intermittent/ no fuel supply then obviously the heater will not be able to start.

[fs123]

It (the glow plug) will be controlled by the booster heater's own ECU for sure, but it sounds like you may have a temperamental dosing pump- due to their exposed position wiring corrosion on the connectors is quite common so I would be checking that out next- the ECU may well be trying to power up the pump but if you've got wiring/ connection issues or a temperamental pump and therefore intermittent/ no fuel supply then obviously the heater will not be able to start.

I will check the pump this weekend but it is strange that the pump can be activated via the VAGCOM output test and ticking can be heard but during normal startup the blower is the only thing I hear before it goes off again.
I'm not sure exactly what sequence the heater operates with but I would expect the pump to be started at least before giving up.

[insanitybeard]

Have you taken a look at the attachment relating to the booster heater operation in this post?

[insanitybeard]

As a side note there is also a diffuser/ strainer gauze which surrounds the glow plug as can be seen in this thread (near the bottom), I believe the function of this gauze is to help the flame front spread out evenly across the burner chamber to allow sustained combustion (though this needs clarification), if this gauze is clogged or burned out then it can cause flame out issues or white smoke due to the diesel not burning properly/ cleanly.

[fs123]

Thanks for the advice. I'll look at that too.

[fs123]

For those interested here's a youtube video that goes through changing of a glow plug and even the dosing pump filter cleaning. It's in German but a good guide visually.

https://www.youtube.com/watch?v=qPogPeaR6hs

[insanitybeard]

So have you got to the bottom of the problem then?

Just as an there's an image of the dosing pump & filter here.

[fs123]

I haven't had time to look at it yet due to work. When I do I will report back.

[fs123]

Update: The old dosing pump was faulty so fitted a new one. I checked both old and new with a clear tubing on the outlet. The old one was not pumping any fuel even though it was ticking. 

However, even with the new pump fitted there is some smoke coming from the mini exhuast but flameout fault is still there. Running out of ideas now since the glowplug and the dosing pump have been changed.

Next I will try putting the old glow plug back in but are there any more things to check?

[johnnyroper]

To have smoke with new glow plug and dosing pump I would imagine it is something to do with either combustion fan/air inlet not providing correct amount of air for clean burning or the fuel nozzle/gauze is at fault not giving nice apart of fuel.

When you did the glow plug did you strip heater or just swap the glow plug?

[fs123]

I just replaced the glowplug withoput checking anything else. I think I will have to strip it but not sure how since most guides only show about changing the glow plug.

I've uploaded a video (Mobile phone quality) of the faulty dosing pump for future reference. Couldn't see any edit option on my previous post for some reason.

[johnnyroper]

They are fairly straightforward to strip down only real problem is the bolts seize in so quite often need to be drilled out.

You can use some 22mm pipe to join coolant pipes up so car can be used while heater is off the car being stripped down

[insanitybeard]

If you've not replaced the diffuser gauze that shrouds the glow plug as mentioned in a previous post then I'd suggest that next, I think the gauze controls how the fuel atomises into the combustion chamber and if it's not doing it's job the fuel and air don't mix properly causing white smoke and incomplete/ unsustained combustion.

[fs123]

Another Update:

I opened the heater again today and changed the glow plug with the old one and also used some compressed air to try and clean the glowplug screen/gauze. The heatersprung into life with lots of smoke which dissipated after about 5-10 minutes. I then tried the new glowplug again and the flame out fault came back which means the new glow plug is faulty or not heating up properly.

After confirming the new glowplug is the culprit, I put the old working glowplug in and tested again and it worked. Put everything back together and tested again and to my dismay there was nothing. The heater wasn't even trying to start and VAGCOM showed everything was off. 

Diagnostics  in vagcom:
no.2 =  ON OFF OFF OFF
no. 3 = OFF OFF OFF OFF

The outside temperature was 4C so I assume the heater should have come on but nothing. I stripped the heater again and made sure all connections were ok but nothing is working now. Just when I thought I had everything fixed the bloody heater doesn't even attempt to start anymore.

Could it be a fuse somewhere? Can anyone tell me which fuses to check?

[johnnyroper]

I would continuity check the wiring as it appears it has happened since you have had heater out a couple of times,either something not fully plugged in or a wire has got damaged by sound of it?

[Chrispb]

Another Update:

I opened the heater again today and changed the glow plug with the old one and also used some compressed air to try and clean the glowplug screen/gauze. The heatersprung into life with lots of smoke which dissipated after about 5-10 minutes. I then tried the new glowplug again and the flame out fault came back which means the new glow plug is faulty or not heating up properly.

After confirming the new glowplug is the culprit, I put the old working glowplug in and tested again and it worked. Put everything back together and tested again and to my dismay there was nothing. The heater wasn't even trying to start and VAGCOM showed everything was off. 

Diagnostics  in vagcom:
no.2 =  ON OFF OFF OFF
no. 3 = OFF OFF OFF OFF

The outside temperature was 4C so I assume the heater should have come on but nothing. I stripped the heater again and made sure all connections were ok but nothing is working now. Just when I thought I had everything fixed the bloody heater doesn't even attempt to start anymore.

Could it be a fuse somewhere? Can anyone tell me which fuses to check?

Fuse 12 is the power supply to heater and fuse 3 for thermo switch, what is the condition of the red wire on the heater multiplug as this one does tend to corrode and break off.
Were there any codes since not starting.

[fs123]

I started the car this morning and amazingly I could hear the ticking of the dosing pump after a few saeconds. The heater started up and smoke cleared after a few minutes. The outside temperature is 2.5C so maybe the temperature sensor is not measuring correctly or it could have been an ECU lockout which cleared itself overnight.

Overall the issue is resolved and the faults were the dosing pump not pumping properly even though it was ticking and the new glowplug I fitted was also faulty.
The dosing pump was easy to remove and refit with the only difficult bit being the crimp-on metal hoseclips being a pain to refit. It is better to use standard jubilee hoseclips to avoid the frustration.

The only thing left now is to see if the heater activates at the correct temperature  which I assume is either 5C or 10C. If it needs sub 3C to start I think the temperature sensor may need to be changed.

[johnnyroper]

Below 10 degrees ambient is when the heater should run if memory serves correctly.

Not worth changing the sensor if it is indeed faulty, run some wires from sensor plug to a switch on dash so you can run the heater when you want to. Especially good in summer months to keep it operational,I have a small rocker switch with an led in one of the blanks by radio.