Leaky injector - Tightening torque DV6FD

[Nego2403]

I'm having black soot around one of my injectors. I'm planning on changing the seals but I'm not sure about the torque at which the clamp holding the injector needs to be tighneted to. Do somebody know the tightening torque for this?
The engine code is DV6FD.

[Nego2403]

Does anybody have this information?

[MattBLancs]

Hi,

Can you confirm if this is the 16 valve version or the later 8 valve version?

If the 16 valve then Haynes Citroen C4 manual 5576 states:
Stage 1: 4 Nm (3 lbf ft)
Stage 2: angle tighten 65°

Note these DV6 clamp nuts commonly seem to work loose (leading to the leakage you've experienced) I have swapped the standard (tubular, Allen head) nuts for M7 Nyloc nuts in attempt to prevent this loosening tendancy. (3 years on, seems to be working)

Matt

[Nego2403]

Hi,

Can you confirm if this is the 16 valve version or the later 8 valve version?

If the 16 valve then Haynes Citroen C4 manual 5576 states:
Stage 1: 4 Nm (3 lbf ft)
Stage 2: angle tighten 65°

Note these DV6 clamp nuts commonly seem to work loose (leading to the leakage you've experienced) I have swapped the standard (tubular, Allen head) nuts for M7 Nyloc nuts in attempt to prevent this loosening tendancy. (3 years on, seems to be working)

Matt

Hello Matt

It is the 8 valve version. The bolt holding the clamp down has an e-torx head. The leak is not very severe but it has a bit of soot around the injector. One thing I'm a little suspicious about is that I've maybe spilled diesel over the injector when I changed the fuel filter and maybe this has cooked and turned dark over time but I remember I checked the injectors last time I changed the filter and there was not any black residue. The clamps do not feel loose when I try to move them by hand.

[MattBLancs]

Hi again,

Ah if it's the later 8 valve then those figures may not be correct, I have a feeling the clamping arrangement did change when the engine was redesigned to 8 valves. Sorry I don't have figures for that version, am sure others may be able to help.

There's a good picture and description of the properties of the injector blow by gunk that forms (often called "black death" ) here:
viewtopic.php?t=73112&start=30

I think it is a mixture of soot and diesel that is baked by the heat, so if looks like that then would think it unlikely to be dried out spilt diesel.

Matt

[Nego2403]

Yeah it does look like that but not as severe. I've listened closely to the engine and I does sound like there's a leak in some of the injectors. A small puffing can be heard when the engine is running but I'm not sure if it is the leak. I would rather check it out now and possibly fix it rather than waiting for the gunk to build up more.

Also I'm a little nervous to do the job as I heard the tightening torques were pretty important to follow. Further the bolt goes into the head so I don't want to break a bolt or something in that regard. Your's is much safer as the stud can be removed if you destroy the nut.

[GiveMeABreak]

For this engine:

(4) Injector Mounting Flange:

Pre-tighten to 0.7 m.daN
85° angular clamping

[Nego2403]

Helpful as always. I appreciate it! I can get to working now.