Glow plugs do not activate even at 0C.

[PhilipA]

I went to Tumut last weekend until Wednesday morning in my 2002 TD5 Auto with 194KK on it.

On Tuesday night it was at least under 0c as the windscreen washers froze , and they have detergent in the fluid. The car had not been started for 3 days so the engine bay would have been cold, but I didn't check the head temperature .

The car started first turn with no glow plug light staying on after the self check.

That I found pretty amazing. I was a bit worried as I have never checked the glow plugs to see if they are OK.
Funny , when I mentioned this to my guests , They said "glow plugs? what are they?" And they own a MuX .
The old girl went well and looks to have done about 12l-13L per 100Km towing my 900Kg camper trailer. and a trip up to Yarrangobilly caves up the very hilly Snowy Mountains Highway.
Regards Philip A

[knuts2au]

I have a volt meter on line all the time, you can see the volts drop while the Glow plugs are on, interestingly they also do an "after burn" when you turn the engine off. And yes it starts straight away if you don't wait! Try that on my 2016 Patrol and it struggles and gives a big puff of white smoke. Gotta love the TD5! [biggrin]

[steve_a]

I'd lay a bet your volt meter is showing the fuel pump.

[knuts2au]

Double checked, you can watch the volts come up when the glow plugs turn off and the fuel pump is still running, plus when you turn it off the fuel pump is off but the volts drop for couple of seconds as well.

[sierrafery]

I have a volt meter on line all the time, you can see the volts drop while the Glow plugs are on, interestingly they also do an "after burn" when you turn the engine off.

I'd say you should think about the bolded part cos it's no way for that to happen...if there is a voltage drop after the engine is off it's for other reason... though it's normal to have a voltage drop when the alternator stops working [bighmmm]

the glow plugs do an "after burn" session only after the engine was started untill the ECT input is reaching 20*C

[Zeros]

How long do glow plugs generally last? My 98 Tdi sometimes struggles on cold mornings...is a double glow before starting a good idea or bad for the plugs? Battery ok, but I guess the starter motor might be getting tired too.