Cold Starting Issues

[adape2003]

Hi,
I am new to this forum but not to the 406 as I have been driving one continually since 1997 (not the same one!). Anyway I currently own a 2003 HDi 90 with S trim and it has done around 80,000 miles. It can be a real pig to start when it is very cold but absolutely fine otherwise, with no poor running, fuel economy or dirty exhaust. I am fairly convinced it is a glow plug issue and am going to be testing various aspects of the system before we start getting the real cold stuff again. I have been under the bonnet for a few hours this afternoon to familiarise myself with where things are but I cannot find the glow plug relay for the life of me. I am expecting to find something with a couple of hefty black wires to it and some control wires too but just can't see it. Can someone please point me in the right direction? I have seen some mention of it being under the throttle position sensor near the air box but it doesn't look like the images I have seen on the net and doesn't look like it could deliver 50 or 60 amps that I believe the plugs can pull.

relay.jpg

Thanks in advance,

Adam.

[paulb2004uk]

Hi,

Follow the cable from the right hand glow plug (gearbox side) to the relay.
The relay is under under a bracket. Has 2 black covered cables and a plug
going into it.
If I can find my pic of it when I get home I will post it.

Your fault may be the glow plugs, they are about £44 from Eurocar Parts.
Avoid Halfords glow plugs like the plague

Good luck

[steve_earwig]

There're quite a few threads on the subject.

Might help: viewtopic.php?f=3&t=8987&hilit=+glow+plug+relay

Here's my one: viewtopic.php?f=1&t=12791&hilit=+glow+p ... ay#p113465

They changed in 2003 so I guess yours could be either

Also, if your injection pump is Siemens then it doesn't have a lift pump, so it could be subject to the same leak issues as the XUDs (check for primer bulb)

[adape2003]

There're quite a few threads on the subject.

Might help: viewtopic.php?f=3&t=8987&hilit=+glow+plug+relay

Here's my one: viewtopic.php?f=1&t=12791&hilit=+glow+p ... ay#p113465

They changed in 2003 so I guess yours could be either

Also, if your injection pump is Siemens then it doesn't have a lift pump, so it could be subject to the same leak issues as the XUDs (check for primer bulb)

That's the one I have (the same one as you that is, the Cartier one), I found it last week finally! I have replaced it as I got a new one from the main stealer for £34 which I was fairly happy with. Hasn't made any difference to the starting issue though I never see the glow plug light come on, even for a split second, and it was only just above 0°C this morning. Even if the glow plugs were dead I would expect to see the dash indicator on as the ECU attempts to apply some pre-heat. All glow plugs are around 2 ohms to earth so no open circuit issues although I have no idea if 2 ohms is deemed acceptable. I am starting to wonder if there is a temperature sensor telling lies somewhere in the system. The temperature gauge works fine and I assume this is derived from the coolant temperature. However there are also fuel temperature and air inlet temperature senders that might be faulty. Does anyone know which sensor(s) the ECU uses to detect if its cold out and some pre-heat is needed? I have read about the MAP Air Inlet Temp Sensor which I wonder about being the cause. Don't think its a simple variable resistor type sender so frigging it with an external potentiometer won't be possible.

I am considering breaking open the old relay one so I can use the base as a way of manually shoving 12V up the glow plugs on a cold morning to see if the old girl starts better.

Thanks in advance,

Adam.

[paulb2004uk]

Hi Adam,

I've had my 406 HDi90 for 5 years, can count the number of times I've seen the Pre Heat light on one hand.
When it does come on it's only for a second.

I was told the best way to check the glow plugs was to remove them and hook up to 12v and see if they glowed.

Good luck

[Welly]

But.. but.. the HDi doesn't need the glow plugs to start as such. They are only there for extreme coldies and to help early warm up for emissions. I'd be hunting for a fuel leak I think?

[adape2003]

But.. but.. the HDi doesn't need the glow plugs to start as such. They are only there for extreme coldies and to help early warm up for emissions. I'd be hunting for a fuel leak I think?

Agreed but I only ever have problems when it's cold, never when its 10°C or above. I have looked for fuel leaks and cannot find anything. I had a Creader V plugged in tonight and the inlet air temperature it was reporting was higher than ambient by 5 degrees so I am wondering if it's telling porkies (car hadn't been started all day so no residual heat). Going to check again tomorrow morning and see what is says........

[Captain Jack]

Had problems as well last year when the car was literally snowed under. Need to replace my glow plug relay....

[steve_earwig]

Still need CJ?

I had a Creader V plugged in tonight and the inlet air temperature it was reporting was higher than ambient by 5 degrees so I am wondering if it's telling porkies (car hadn't been started all day so no residual heat). Going to check again tomorrow morning and see what is says........

That sounds like a possible, any joy?

I've had my 406 HDi90 for 5 years, can count the number of times I've seen the Pre Heat light on one hand.

I haven't spotted mine yet but not to worry, I'll soon be seeing too much of it

[grasmere59]

My 110 was a pig to start last year when it got down to minus figures,anything above that temp and it's fine,blink and i would miss the glowplug lamp,i was going to change the glowplugs but they looked as if they were'nt coming out without a fight so left well alone for fear of breaking them.I found turning the ignition on and off a few times helped the glowplugs a bit.