2ltr tdci 140bhp, 160k on a 57 plate, I'm having serious low power below 1500 rpm then it kicks in really hard, this doesn't happen all the time but it's happening more often, checked inter cooler hose for splits non found or heard, so I'm thinking turbo actuator.

Car drives fine above 1500 rpm and fuel consumption is good 55mpg up the motorway from Lancashire to Scotland 400 miles at motorway speeds so not much up otherwise.

Any ideas?

No one?

Apparently not!

From the date, that could be a late Mk3 or an early Mk4, which is it?

In any case, the first place I'd look would be for leaks in the boost hoses. I know you have had a look already, but these things can hide, so look carefully - probably best, after an initial inspection, to get someone to rev the engine for you and see if you can feel any air coming out, as some leaks will only open up under pressure (being careful of rotating parts and all the other usual warnings, etc).

MAF next - check it is clean and the wiring ok. Some contact cleaner on the contacts and work it in and out a few times.

Any reason to think that cam or crank sensors might be suspect (removed recently, or DMF problems)?

I'm afraid then you are probably on to serious stuff.

Edit

Should have asked: Is it the same hot and cold, or is iot different while warming up?

It's an early mk4 no difference hot or cold and it's intermittent, also discovered today that it sometimes won't Rev in neutral so it not just under load. No fault codes showing up using Forscan, much baffled.

Got a fault code this morning p1335 which relates to EGR not closing fully so at low revs it's getting to much recirculated exhaust at least I now now where I'm looking

Further update, turns out nowt to do with the EGR, knackered battery was the cause, thinking back it only started happening after I changed the battery, so popped of to my local garage who confirmed my theory that the battery was indeed duff, new battery and all is well, just goes to show how electrically sensitive these cars are, and I thought my Citroen C5 was sensitive nowt compared to these.

Totall cost bill just some time result

Now got a problem with the fuel gauge, very slow to come up to level and then seems stuck at half and I know I only have a quarter of a tank, must be battery related will try a reset tomorrow

Odd; EGR sounded plausible to me (in the 'Why didn't I think of that' kind of sense). But, if the battery is seriously off, it can have all sorts of bad effects, but it does have to be seriously off (as in a cell or two shorted out, and a nominal 12 volt battery becomes a nominal 10 or 8 volt battery).

Anyway, good luck!

Fuel gauge was fine this morning so all sorted