C5 2.2HDi 170Bhp Glow Plugs

[Vallunstein297]

Hello guys! I've got a small question for the 2.2Hdi owners. Last winter I had small problems with starting up the car. I'm from Bulgaria and we usually have a cold winter so temp's go below -10 very often. The problem is the car cranks for at least 2 seconds when it's very cold,but I haven't noticed the glow plug indicator lighting. Sometimes the glow plug indicator flashes on during summer time,when it's very hot,but It doesn't when it's cold Any idea how can I solve this issues?
Little Edit: I forgot to include the car is from 2007 (Facelift of C5 I)

[GiveMeABreak]

It would be helpful to scan it with a code reader.

If you get fault:
P1350: this will be the pre-heater Relay for the Glow Plugs
P1351: If you get this it will likely be the glow plugs that need replacing.

Normally the glow plugs in warmer countries are rarely used on startup with the HDi engines, but can assist with regeneration. However in very cold climates, the glow plugs are probably used much more.

As far as the glow plug light on the dashboard goes - neither my C5 X7, nor my previous MK II C5 ever had the pre-heat light on and neither does it on the C3 HDi either.

So if all is working fine leave it. If you are having starting problems though, maybe time to replace them or check the relay.

[Vallunstein297]

It would be helpful to scan it with a code reader.

If you get fault:
P1350: this will be the pre-heater Relay for the Glow Plugs
P1351: If you get this it will likely be the glow plugs that need replacing.

Normally the glow plugs in warmer countries are rarely used on startup with the HDi engines, but can assist with regeneration. However in very cold climates, the glow plugs are probably used much more.

As far as the glow plug light on the dashboard goes - neither my C5 X7, nor my previous MK II C5 ever had the pre-heat light on and neither does it on the C3 HDi either.

So if all is working fine leave it. If you are having starting problems though, maybe time to replace them or check the relay.

Thanks for the reply! My country is really hot during summer and decently cold during winter times Last winter I had one case where I went to start the car but it resulted in failure. It was the coldest day in the whole year and I suspect my fuel had frozen. It happened in early morning and when I went to try again in the evening everything was fine.

[cit-rotti]

Hello,
the C5 2.2 HDI 170 would have to be a C5R and without properly functioning glow plugs starts considerably worse from -2 to -5 degrees.
Even one or two defective glow plugs require a few turns before the engine starts.
Exam:
The glow plug relay is located under the engine control unit and measurements can be carried out there quite well.
Measurement method 1 = with a clamp ammeter. The
Relay remains connected. The total current (thick cable) and one of the 4 cables to the glow plugs can be measured. The total current is 50-60A and then falls until the relay switches off. Each individual glow plug has 12-14 A - the current slowly decreases.
Measurement method 2 = with an ohmmeter. To do this, the plug must be disconnected from the glow relay and the respective + supply line to the candles must be measured against ground. Good glow plugs have a very low ohmic value.
Replace all glow plugs - not just the defective ones.
The longer a defective glow plug remains in the cylinder head, the greater the problem of removal, because it becomes clogged without glowing.
Greetings Wolfgang

[Dommo]

I changed the plugs on my 07 2.2 170hp C5 facelift, the job wasn't toooo difficult if i recall but quite a lot has to be removed to get to them, including the fuel filter.

Incidentally around zero degrees my glow plug light DOES come on, so it does exist on these cars!