Loss Of Power At 3000Rpm

[Bert66]

My C4 1.6 hdi runs fine but the other night I overtook a slow moving Lorry after a roundabout and experienced a dramatic loss of power when the car reached 3000rpm (in 3rd). I managed to get past and put the car in 4th where it continued to run perfectly normally.

 

This morning, on a quiet stretch of road, I put the car in 3rd and when I reached about 3000rpm, the same thing happened.

 

Has anyone else experienced this? I don't think the car is going into limp mode as it continues to drive normally when you drop the revs.

 

There's no obvious damage to the turbo actuator vacuum pipe so was wondering if it could indicate an EGR issue, possibly not opening when it should. Do this sound feasible?

[paul.h]

Does it do it at 3000 rpm in any other gear ? If it was limp mode the engine management light would have come on. You might need to check the turbo boost pressure in case it is too high (or the sensor is faulty) and being limited.

[Bert66]

I've not tried in other gears, I'll find out.

[paul.h]

Somebody on the C5 section has just posted their 2.0hdi C5 hesitates when 3000 rpm is reached. One thought was the fuel filter may be due a change. When was it last changed on your C4 ?

[Bert66]

I changed it when I did the turbo so it's new. The symptoms are so abrupt that I'm wondering if there are any changes to the engine (management) at 3000rpm which could cause this.