Diesel fuel leak – C4 Cactus 1.5 BlueHDi – High pressure pipe issue?

[Roda]

Hello,

This is the third time I'm experiencing a diesel leak and spray, which can cause serious problems and is very unpleasant.

The last time it happened, I was on the highway with my baby on board when I suddenly noticed a strong diesel smell inside the cabin, and a red engine warning light came on.

I’ve already had the fuel high-pressure pipe replaced twice, as it was identified as the source of the issue.

However, since this is now happening for the third time, I’m wondering:

Could the fuel pump be the root of the problem?

My mechanic is not entirely sure, but he suspects that the 7mm chain (which has not yet been replaced) might be causing vibrations, which could lead to repeated failures or stress on the fuel system. He suggests it might be worth replacing the timing chain as a preventive measure.

Has anyone experienced similar issues with the 1.5 BlueHDi engine?

I’ve attached a photo showing the exact part involved.

Any help, insights, or shared experiences would be very appreciated!

[PaulC5]

Which bit on the pipe is leaking - is the pipe splitting or a seal at one end leaking ? Were the replacement parts from a Citroen dealer or something made up to fit ? Were the nuts done up to the correct torque value ? Has the fuel pressure been checked to make sure it is not too high ?

[Roda]

Thanks a lot for your helpful and logical suggestions.

The leak is occurring exactly at the joint – where the pipe connects to the fitting – not along the body of the pipe itself. At first, the mechanic said the old pipe was just loose, but after tightening it, the leak continued. That’s why the pipe was replaced. Every time original parts were used, not aftermarket or improvised ones.I'm not sure if the joint was tightened using the correct torque spec, and as far as I know, the fuel pressure hasn’t been checked. Everything you’ve pointed out makes perfect sense, and I’ll definitely ask the mechanic to verify both the torque values and fuel pressure.