DS4 1.6 e-HDi 9HR/DV6C – rough running, much better with MAF disconnected

DS Automobiles Citroën DS4
1

Hello everyone,

I have a 2012 Citroën DS4 with the 1.6 e-HDi / HDi 112 hp engine, engine code 9HR / DV6C.

I have been chasing an intermittent rough running issue for some time. The engine starts immediately, but especially when cold it may shake for 1–2 minutes. The main problem appears during transitions: pulling away from traffic lights, light acceleration after slowing down to 30–40 km/h, or gentle acceleration after changing gear. At steady speed the engine runs very well.

I have done several checks with Diagbox and an Autel scanner. The most interesting result is this: when I disconnect the MAF / air flow sensor, the car runs almost perfectly. The hesitation and jerking almost disappear. Of course, with the MAF disconnected I get the expected MAF-related faults, such as P0102 and P0113, and the ECU goes into fallback mode with measured air flow = 0.

When I reconnect the MAF, the rough running comes back.

I also noticed something suspicious. The large corrugated intake hose fitted just after the MAF body moves quite easily on the MAF housing. There is no metal clamp there. I looked at pictures of a compatible VDO/Continental MAF, and the long neck where the hose fits seems completely smooth, with no groove for an O-ring.

My question is:

On this 1.6 e-HDi / DV6C engine, is it normal for the large intake hose after the MAF to be simply push-fitted without a clamp and without a visible O-ring? Should it move quite easily, especially when warm, or should it be tight on the MAF body?

The hose seems to correspond to PSA part number 9683725080. I am wondering if the hose may be old, hardened or enlarged, allowing unmetered air after the MAF and disturbing the EGR/injection strategy.

Has anyone had a similar issue on a DS4 / C4 II / Peugeot 1.6 HDi DV6C?

Thank you.

2

Any leak between the turbo and the mass airflow sensor causes problems.
There must be a clamp on the mass airflow sensor side and a proper seal on the turbo side.

3

yes, this is my opinion too…but I looked for more pictures of this engine and nowhere did I see it have a metal collar there (like I’ve seen on other cars) - I think maybe it has an o-ring that is not visible…but I couldn’t find any code, or a schematic/diagram where I could see this).

4

It might not have a clamp, but there should be a gasket inside the pipe consisting of three rings. Even if you put the clamp on, it won’t do any good without that seal. Check if it’s there.

CITROEN 1.6 HDI 9683725080
CITROEN 1.6 HDI 9683725080866×816 45.4 KB

5

That was my suspicion (I haven’t removed the hose completely to check yet)…is the gasket separate from the tube or is it made of the same material? I pulled the tube a little and it seems to move very easily…if I pull a little harder I can feel it coming off the MAF tube - shouldn’t it offer some resistance if the gasket is in good condition?

6

It should.

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