Water heating 'glow plugs'

[green A8]

I've had a fun day servicing one of the families B5 1.9 TDi's. This time it's a 1997 Avant (AFN) with just under 195,000 miles on the clock.

The question I'd like answering, what is the part number of the three 'glow plugs' that are fitted to the water heater located at the rear of the engine block. These glow plugs supply warm water to the heater on cold start up, they do not heat the fuel. The reason I'm asking is that all three are dead, I'd say they gave up the ghost a couple of years ago at least. But, as power is still reaching them I'd like to replace these defective parts. I assume that a warmer coolant equalls slightly better MPG, and a warmer interior. (That's what I told the car's owner, who suddenly became very keen on getting new parts fitted)

I also noiced that the temperature gauge is AWOL, I suspect that the culprit is a defective temp sender, as I can still get a temperature reading of 90 degrees through the digital climate control readout. (Channel 51 if I remember rightly). The existing temp sensor is a blue square four pin item. I have a black four pin square sender 'in stock' complete with 'O' ring and plastic clip. I've no idea what the part number is, for the black unit. Would the black one be a suitable swop, or does it HAVE to be an identical new unit (blue)?


Thanks in advance for any help.

[Doctle Odd]

1x Bosch Sheathed Element Glow Plug 0250201036 | eBay

[zollaf]

i replaced the ones in mine a while back. turns out they are the same ones as used in the earlier indirect injction diesel engines

[adamss24]

They only work if you turn the blower to max, they don't work all the time...