Glow plugs, what temp do they start working?

[EvilTwin]

OK I've had my 406 for about a month now, its an HDi, but one thing I'm starting to wonder about is the glow plug system.

I understand that they won't activate while the engines warm enough to start with them. But at what temp do they activate?

In the mornings when off to work at the moment, the outside temp gauge can be as low as 10 degrees C the warning light for the plugs does not illuminate. In fact I've not seen it come on so far, so what temp are they supposed to start working? or should i be checking the bulb?

I want to get the car checked out, and sorted before the really cold mornings come along.

Also does the fuel system have a pre-heater to warm the fuel prior to entering the injectors?

[HimBigChief]

If it starts fine, then no need to worry about the glow plugs.

My missus has a 306 HDi estate and the glow plug light barely comes on on that, usually more of a flicker. On my 2.1DT it comes on and stays on for a few seconds.

[steve_earwig]

Here and here for a start (ha!) I know on mine I'll start to see it when it gets below zero but it's so quick blink and you've missed it. All the times are actually in Haynes.

[EvilTwin]

Thanks for the links steve, just wanted to be sure...

[Welly]

There's nothing usually to worry about with cold starts in fact the HDi doesn't rely on the glow plugs to start. They do run though and stay on for at least 60 seconds after the engine fires. I think they come on when the coolant temp is less than 10 degrees and vary the length of time according to coolant temp.

The Diesel get's directed through a thermostatic heater element in cold ambients too although I never found mine

The coolest 'secret' to the HDi in deep winter is it's 'Electric Heater' there is a series of electrical resisters before the heater matrix to heat up the cabin quickly because the HDi is so efficient it cannot put enough heat into the coolant quickly enough. It's called 'Additional Heating'.

[BruceT]

There's nothing usually to worry about with cold starts in fact the HDi doesn't rely on the glow plugs to start. They do run though and stay on for at least 60 seconds after the engine fires. I think they come on when the coolant temp is less than 10 degrees and vary the length of time according to coolant temp.

The Diesel get's directed through a thermostatic heater element in cold ambients too although I never found mine

The coolest 'secret' to the HDi in deep winter is it's 'Electric Heater' there is a series of electrical resisters before the heater matrix to heat up the cabin quickly because the HDi is so efficient it cannot put enough heat into the coolant quickly enough. It's called 'Additional Heating'.

Welly,

Good info, when you say 'secret' do you mean it needs to enabled or just people dont know its there/functions etc?

The mrs diesel 90 its great but I said to her it will be winter when you see how good it is expecting glow plugs to troublesome etc (Old diesel myths etc) as its our first... I also though demisting the inside would be a problem because the HDi takes so long to warm up at idle but this little electrical heater should be good.

Cant wait to get mine now

[Welly]

I should clarify it is not an electric 'air' heater - it's a water heater to boost cabin temps via the heater matrix.

Secret by virtue of no-one really knowing it's there, and it not being described anywhere in the manual I suppose

Glow plug wise even in the very coldest morn at, say, -8 deg's mine would always start on the button with just a tiny hint of miss-fire for the first 10 seconds or so. Quite impressive really.

[Doggy]

Agree with all of the above, but the HDi's a direct injection engine, unlike the 1.9/2.1TD's. Direct injection engines are far less dependant on glow plugs, whereas indirects are known to be 'difficult' starters unless all is well glow plug wise.

My bro's old Montego direct injection engine would start without waiting for the glow plugs on all but the coldest of mornings - as he says, 'you wont do that with an XUD'.

[Welly]

My bro's old Montego direct injection engine would start without waiting for the glow plugs on all but the coldest of mornings - as he says, 'you wont do that with an XUD'.

Awwww, the unmistakeable sound of a Perkins Diesel cold-starting

[Doggy]

Awwww, the unmistakeable sound of a Perkins Diesel cold-starting

Tell me about it - my neighbour's got a N reg sherpa van thats somehow still going, reckon it's only the muck & cobwebs holding it together

[Bundy]

Meh, HDi's... luxury...

When i were't lad, our 1.9 TD 406's used to turn over for 10 seconds after the glow plug light went out fire on 1..2..1..2..4 and then fill 't road up with smoke, followed by 10-15 seconds of the noisiest diesel rattle you've ever heard in your life. I should really replace the all 4 glow plugs this year and not just the easy 2

My neighbours must have loved me and my 5:15am starts

[jasper5]

The Diesel get's directed through a thermostatic heater element in cold ambients too although I never found mine

My Peugeot Expert HDi has one of these under the passenger's side floor, that's where they usually are.

[Welly]

The Diesel get's directed through a thermostatic heater element in cold ambients too although I never found mine

My Peugeot Expert HDi has one of these under the passenger's side floor, that's where they usually are.

Yeah my 406 had one of those - like a serpentine of aluminium piping on a black plastic 'track' thing but I was told that was a fuel 'cooler' before it gets lobbed back in the tank (hot fuel return from the rail).

I understood the fuel pre-heater was connected vie the thermostat housing and the fuel filter housing/tubing

[jasper5]

Looks like it is a cooler on mine, the fuel pipes go into a small radiator with a plastic scoop on it.