C5 2.2hdi air system engine and brakes ?????

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

User avatar
Posts: 973
Joined: 29 May 2011, 22:56
x 8

C5 2.2hdi air system engine and brakes ?????

Post by waynedance » 15 Apr 2013, 20:10

Ok another 2.2 mk1 question.

Now firstly engine seems to have plenty of power but does seem to slightly hold back.

When starting engine after being left for a while you need to give plenty of acceleration and the engine will not give full revs for about a minute or two, as if air is being built up.

Also when starting from cold and the first or second press of the brakes the pedal will sometimes creep down, are all these problems related or am I barking up the wrong tree.

Posts: 91
Joined: 12 Feb 2008, 23:35
x 2

Re: C5 2.2hdi air system engine and brakes ?????

Post by RustyUK » 21 Apr 2013, 23:51

When I first got my 2.2 MK1 (5 or 6 years ago) the accelerator cable had stretched. Fixing that made an enormous difference, something simple worth investigating perhaps.

Brake pedal not sure, leaky master cylinder? The brake vacuum is derived from a pump on the end of the camshaft, the vacuum also controls via electrovalves the turbo boost, EGR, swirl valve and heating or cooling of air (butterfly valves block the cool air to admit heated air during DPF regen). I don't know if weak vacuum can cause pedal drop, but perhaps worth checking the vacuum hoses for leaks too (although lack of vacuum will soon cause a turbo overboost fault, it'll throw it into limp-home mode but you'll get an antipollution fault flash up, anything that awry should be obvious).