Air In Diesel Fuel Line C5 Hdi

[John.A.S.]

Hi all,

 

C5 HDI 2.0ltr VTR  (2006)  ( VF7RCRHRH76734809 )

 

Checking over the car for a fault that's taking some finding I noticed a few small air bulbs in the clear plastic fuel line between the fuel filter and the high pressure pump while the engine was running. increasing the revs produces a multitude of large and small bubbles initially then reduces to a trickle of small bubbles. The filter has done less than 3k so should be OK but I did notice a yellow o'ring in the supply line connection I have 10mm x 2mm and 10mm x 2.5mm o'rings, but this one measures 10mm x 2.25mm. The o'ring is not shown on Citroen box so don't know if its a part you can order on its own.

I do not have a lift pump in the tank so the fuel is drawn from the tank by the high pressure pump. The car always starts first time.

If the fuel was draining back to the tank overnight due to air ingress it would be slow to start in the morning so I am guessing the air is being drawn in buy the pump when it is running and the bubbles occur instantly when the revs are raised so possibly something to do with the filter housing.

 

Anyone had this problem.

 

John. 

[paul.h]

Have you tried using the hand priming pump to remove the bubbles ? Our C5 (2.2 hdi 2007) does not have a clear pipe from the filter to the hp pump but has a clear pipe to the hand pump from the filter. This clear pipe often has an air bubble in it which can be cleared with the hand pump.

[John.A.S.]

Yes tried the primer, it clears the bubbles but as soon as the engine starts the bubbles start again.