Auxillary heater.

[nickmc]

Hi All,
Apologies for raising same old questions but could do with some advice.(This is my first thread).
I have a 52 plate alhambra diesel 115 which developed lots of black smoke from aux heater exhaust and smell of unburnt fuel.A bloke at work plugged in his diagnostic tool which displayed "repeated flame out" and then "Function lockout"He cleared these faults but smoke still reappeared so a week later I changed the glow plug on aux heater (with some assistance).
The next 2 mornings I have had an excessive amount of what looked like whiter smoke until the engine temp. reached 85ish. I also heard the sound like a jet engine from the heater.
Does this mean the system is working correctly or is there a possibility that the fault codes need resetting again or that there is more to it than I thought?Thanks in advance for any advice.

[matthewgdavies]

This is quite normal, if the system detects that the glow plug is not working properly it logs 'repeated flameout' and shuts off the aux heater fuel pump(if it didn't the unit would fill with unburnt fuel which would eventually leak onto the road just in front of the n/s/r wheel causing quite interesting handling effects - It will then try and fire up again the next time the aux heater criteria are met (ambient below 5 or 10 deg C dependent on model and coolant temperature below abt 75 deg C)
For safety reasons after four 'repeated flameouts' the system, on the fifth attempt will lock the heater out and not operate it again until the codes are cleared. In your case as you used the heater in a faulty state before replacing the glow plug you may already have up to four new flameouts recorded - in short it's best to clear the codes again. The dense clouds of white smoke you are now getting are the glow plug clearing out the accumulated unburnt diesel in the unit - this will stop after a few days (depending of course on how much excess diesel is present and how long the heater runs for each time). Mine took two days and had the local fire brigade interested
I cannot understand why people disconnect these units - changing the glow plug is very fiddly but it is a service item and the unit would not be fitted if VW/Seat did not think it was necessary - after all you wouldn't disconnect your brakes because your pads need changing

[nickmc]

Thanks for advice.The smoke seems to have got less over several journeys,although because of the times I have been travelling (early mornings) I have not been stuck in traffic so have not really had to stop in queues.Time will tell!!