ok so i have an a4 1.8T w/ a swapped motor that has everything listed in my sig. so driving home from work today the car is running fine, then when leaving the last traffic light before i got home the car felt very sluggish, but was ok other then that, then around the block from my house as soon as i hit boost, it felt like i was at the rev limiter, or a fuel cut or something like that. so i turned down the music and drove around the block a few times, every time i would hit boost, the car would feel and sound like im at the rev limiter, even at 3k rpm's. the turbo sounds loud as hell, like when i was boosting 20lbs so im pretty sure i didnt blow the turbo. im not exactly sure what it is yet though so im askin for some help w/ that. if the turbo spools up to 0 lbs normally, that would mean if its a leak its on the vaccume side right? or does this sound like the wastegate?

my tuner is booked until tommrow and i have to go to class at 6 so im not sure if i should take the car or not. its not a problem unless i hit boost.

so anyone else have this happen? and things i should check first ect. i know its kind of a long story so anyone that can help me i appriciate it. thank.s.

 

stock turbo?

 

need more info...like does it jerk or steady rev up?

 

Could be a leak at the fmic. There should be a blocking plate on the fmic for engines that don't have a map sensor (like yours). If that plate is not put on, comes off, or becomes lose, you will have a big boost leak. Even if thats not it, it sounds like a boost leak somewhere. Check everything between your turbo outlet and the throtle body.

I only bring the fmic blocking plate thing up because this is exactly what was happening to arif's car when he forgot to use the blocking plate. You fmic might not even have that option.

 

Not sure since this is a pre map car, but on mine if you blow a pipe off or have a big enough leak to not get any psi, the car wouldnt really go and would stall when the rpms dropped. Since you can still drive the car and its making noise, the wastegate flapper being stuck wide open could explain the car still moving and not making any boost. If it was a vac leak, the wastegate wouldnt open and you wouldnt be able to stop boosting. Best of luck finding the source, you have had enough BS with this car recently, so i hope its nothing major

 

thats what im thinking it is. i know what a leak in the FMIC or anything after the turbo feels like so iknow its not that. im not sure if a leak on the exhaust side would make the car act how it is, so im really thinking its the wastegate. its save to drive though right?

 

I would barrow a car if you can or hitch a ride. It shouldnt harm anything really, just **** off the ecu and probably kill the mpg. If its not far, you could drive it a handful of miles if you are bold enough.

 

well i looked under the car again now that i had a little more time, there was a loose clamp on the silicone pipe from the turbo to the i.c., i tightened it down and went for a ride, the car boosted for a few seconds then stopped again...so thats the problem right?? wrong, i went back under the car and the silicone hose hasnt moved. now im really confused. im gunna try to get the day off from work, or at least shorten it so i can fix this once and for all tommrow. we'll see what happens.

 

It would take more than a loose clamp for it to not boost. If it was boosting, it would blow the pipe off very fast with a loose clamp

 

yay! everything is fixed. a few hours at my buddys house after school and i got all the kinks worked out for now.

we cleared all the codes. 2 misfires from a while ago, and one for disconnecting the MAF casue my friend said if i do that and it still wont boost then that was or wasnt the problem...w/e i forget but it didnt work haha.

after clearing the codes i still wouldnt boost right but it was out of limp mode so a leak in the vac line became very obvious. i have rubber lines w/ fabric around them, so i couldnt actually see the crack in the line but when we took it off the car the hose was split in half.

after changing that and replacing all screw down clamps on the i.c. piping the car is happily boosting at 20psi w/ no problems.

i did however realize a tranny mount is either broken or about to brake so thats next on the list.