every morning i start up my car and let it run for about 3 min. i dont know if this isnt long enough or what but when i first take off the turbo makes a sound like its not all the way spooled up till i hit 3rd gear. in this time there is also a noticable power loss or lack of boost so i know its the turbo. i have a 99 a4 with a ko4, if i leave it set for longer about 5 to 7 min there is no power loss or sound from the turbo. i am wondering if its just a bomb waiting to go off or is it normal to not spool up till you start driving down the road?

 

I guess you really need to invest in a boost gauge. This will be a sure way to tell if your not fully boosting. You need to describe the sound better too. Is it a grinding sound, or just the typical sucking air sound? A sure way to know if your turbo is gone is smoke coming out of the exhaust and a major loss of power. It also could be a diverter valve issue, or even a wastegate issue. But seriously though u need to get a boost gauge.

Update: (lol from like 2 seconds ago) I got my gauge at pepboys and i just did a custom vent gauge setup only cost me 60 bucks. Takes a little time to get the vent pieces cut out but its worth it, it looks dirty.

 

oh yea dude i already have a gauge and yea its got no boost sorry about that...more of a grinding sound but that that bad i know its prolly not going to be that bad off since after its in 3rd gear it doesnt do it the rest of the day just when i first start the car each morning

 

Oh huh thats weird. ive got the same car except a 2000 and it makes a grinding noise at high rpms, usually in first and second gear. Im also thinking its my turbo but im not too worried about it cuz im going BT this spring. Truthfully though you could have a crack in the turbo. Thats what im thinking is wrong with mine, i never knew there was a proper way to cool down the turbo after beating on it for a while.

 

oh yea deff have to cool it down right, possibly crack but you fry the oil in it=bad juice..lol iv got a greddy timer in it always been carful except one time i had to pull it in the driveway quickly and turn it off lol not going to say it was the 5-0 but they just happend to fly by lights and all lol

 

not sure about the noise, but the car will not boost as high in first gear as the rest.