Lots of turbo noise on my Audi A3 TDI 140. Mostly at low speed, sounds, sounds a bit like a jet engine (the whine not the roar), Thanks tim

Hello everyone having similar sort of issues , any help would be much appreciated ,, trouble with my 04 plate a3 2.0 tdi , the car loses power in first and second makes a lot of noise but doesn't really go anywhere but if ease completely off and back on again the turbo kicks in properly it also won't go over 4000 rpm unless I go off and on the throttle any help would be greatly appreciated also I took the vacuum resivour pipe off whilst checking a few things and it cured it until I was cruising down the motorway and it just lost all power so I stopped and put vacuum resivour pipe back on and after about 15 mins the vacuum must have built back up again because it was back to just being useless in 1st and 2nd gear ..???????? Help !!!! I'm lost

NO THE PROBABLE CAUSE IS A VALVE THAT ADJUSTS THE TURBO PRESSURE!CHECK FOR DTCS FIRST AND LET ME KNOW!!

Code P0234 Check N75 boost control solenoid and all vacuum hoses to and from N75.

If performance returns after brief ignition key cycling, Off /On.....check for vacuum to turbo dump valve canister.

If performance is always low, check turbo vanes for sticking or 'snow screen' in snorkel to air filer is not restricted..

This may sound obvious, but I would have your brakes checked out, just to rule them out. Many shops will do a free brake inspection.
If the noise is coming from the engine, look for a "Check Engine" light. If you see that, then have someone hook up a scanner to check the codes thrown by the car's computer and go from there.
A grinding noise is not something you want to put off or wait to fix.

Check or replace the air cleaner element. If this is slightly blocked it will have this affect.

It's most likely the turbocharger. We used to have an Audi with a turbo and it had a bit of a whine when accellerating. A slight siren type of noise is normal for it, but, if it's real loud then it should be checked.

Turbo vehicles often sound like they are whistling when the turbo spools up because it is sucking in air at a high rate and it makes a bit of a whistling sound. Generally not a problem unless it is a different whistling that you are referring to.

Check the idler and tensioner pullys for your serpentine belt. I suspect the whining noise heard earlier was due to the fact one was getting a bit stiff or rough turning. When you gave it that extra fuel, the sudden load may have finished it off. Sometimes they lock up, and sometimes they fall apart. Check those items first.

Could be low oil level indicator tha auto shuts of engine if oil goes low

might wanna have the dealer check it out or look at the blades on the turbo cause its bad to drive on damaged turbo