Popping noise
 

New mounts , new tcv ,new boost solenoid new turbo.

Its been in the garage today , the fella says the fat pipe to the egr should be hard when the engine is running , which it isn't.

Can a problem with the egr cause a vacuum leak?

Hi what fat pipe to egr ?
Do you mean the air pipe to the EGR mixer pipe then to the engine inlet,
This pipe will only be hard when the car is making boost pressure , it will not make boost on tick over,
if it is this pipe run away do not use this garage , he does not have a clue,
Yes the egr can make a vacuum leak if not closing, the egr valve should be closed when car is making boost,
Dave

At a loss really , i will put that to them .

Having replaced most things and still having a problem , I'm not sure what's next.

The car has no guts down low but at motorway speeds its got power??

Hi you need to log the boost vs rpm, do this in 3rd gear,
is this why you have fitted a new turbo,
have you tested it for any boost leaks,
Dave

is there any smoke when the car is driving

No smoke , btw I'm no mechanic.

I fitted the turbo because everything pointed at the turbo.

My guess now is the problem is before the turbo but not sure what, most garages are clueless to this engine.

Had a similar problem with my 2003 D5 Manual. The cause was a low vacuum output from the vacuum pump at lower revs. Needs to be checked with a vacuum gauge to see if the vacuum is good at idle and low revs.
I fitted a second hand vacuum pump and the power at lower revs returned.

I don't know why, it is simple, I am not a mechanic,
Has a boost leak test been done ? do a boost leak test/ smoke test,
remove the plastic panel under the intercooler, is there any oily gunge under there, if there is you need a intercooler, but do a smoke test,
Dave

Yes that is a very good point,
Dave