severe bucking/overboosting

[Cesarlcase]

To get to the point My car is pretty much stock just a greddy b.o.v, t4 turbo and 2.5 inch exhaust. The car has been great since last summer;only 93 octane gas used. The problem with my 2g is whenever i give the car 2/4 of throttle it will buck severely,can't even go over 35-4000 rpm. But if i give it 1/4 throttle I could drive the car all the way up to 7k if i wanted. Pretty much the problem starts when the boost goes up, i could hear the turbo SPOOLING but no power.Once i release off the gas pedal and the boost goes back down,i could then give it more speed without the car bucking until the boost goes back up. I've read that it could be a leak in intercooler piping...idk if thats the case haven't checked yet. Also I'm guessing it could be a bad wastegate,is there anyway i could check if the wastegate isn't operating. Any other opinions would be much appreciated. Please help me out here. Don't want to give up on my car.

 

[drewboi]

do you have a 6 bolt or 7 bolt in that, i checked your profile and it did not say.. either way... it sounds similar to what i had going on and it was my knock sensor picking up my lifter tick and other crap .. but i have a 6 bolt with the crappy lifters.. id say it was your knock sensor picking up something.. check all the mounting brackets on stuff like alternator , power steering, etc.. check it out at idle and see if any pulleys may be wobbling.. ... does your engine make any noises that aren't exactly normal?

 

[Cesarlcase]

do you have a 6 bolt or 7 bolt in that, i checked your profile and it did not say.. either way... it sounds similar to what i had going on and it was my knock sensor picking up my lifter tick and other crap .. but i have a 6 bolt with the crappy lifters.. id say it was your knock sensor picking up something.. check all the mounting brackets on stuff like alternator , power steering, etc.. check it out at idle and see if any pulleys may be wobbling.. ... does your engine make any noises that aren't exactly normal?

My car used to knock like intermittently on start ups till it warmed up. My car makes music for me in the morning...sometimes i would hear a whining sound/sometimes i hear a hissing sound somewhere around the intake manifold...been like that since i got But a knock sensor could cause all this?

what he means by over running your fuel system is that for the amount of air you are pushing into the motor there is not enough fuel to match because your fuel system hasn't been upgraded enough..... what exact fuel mods do you have ????? in none you need some what exact turbo are you running? based on that will be what kind of mods you need for your fuel system.what boost are you tring to run? Also what kind of wastegate are you running internal or external?

I updated my upgrade list. My car has been running fine for a year,it suddenly started doing this one morning. The problem is that it's overboosting really bad. I wouldn't start off with the fuel system because i already know that the overboosting is causing the car to act like this. I'm just curious what would cause the overboosting to happen. And i have a external wastegate...

 

[drewboi]

yea.. a knock sensor can cause this if its what i think it is.. mine would do it till i cleaned my lifters and changed a few little things in dsm link..... i would get on it and it would die then i would slightly let off the pedal and get back on it till it did it again... some times it would pull like no other without dieing down.. sometimes it would do it under the slightest load

 

[Cesarlcase]

I'm still a noob to this all,so i want to thank everyone for there help and patience. Anyway a few minutes ago i went looking under my hood and i notice on the turbo that the intercooler pipe that connects to the turbo was devilishly loose as if was slowly sliding down because you could see the difference between the relatively dirty turbo to the new revealed portion of the turbo. So when i realised this i tooked a blunt pipe and pushed it just a bit and it literally almost came off. I'm about to try and fasten it...but i have to step out really quick so i wont be able to do it till later. Would this cause that kind of problem?

Thanks.

 

[killer_eclipse]

you need to do a boost leak test for the first several posts people were telling you that... what turbo are you running???? as far as the over boosting is conserned i think you are tring to run to little of boost for how big your turbo is.

 

[colbyc]

you need to do a boost leak test for the first several posts people were telling you that....

this..

 

[Cesarlcase]

you need to do a boost leak test for the first several posts people were telling you that... what turbo are you running???? as far as the over boosting is conserned i think you are tring to run to little of boost for how big your turbo is.

I did... I brought it to some mechanic and he tested it for me and said i had little leaks in my throttle body and i fixed that and my b.o.v hose had a leak fixed that. after he said there was none...

 

[colbyc]

buy a boost leak tester and test it yourself, but anywho takin your word theres no boost leaks at all
what turbo exact are you running man?

 

[Cesarlcase]

buy a boost leak tester and test it yourself, but anywho takin your word theres no boost leaks at all
what turbo exact are you running man?

I'm glad i bought one today!!!! I bought the tester tested the car and it was making this shhhhhh sound... and i was shocked because the sound was quite obvious and the mech i brought it to said it was okay. Any how,i saw that flexible hose that connects the turbo to the intercooler,literally slipping off,with a pretty big hole on the side!! I tightened it back on. took it for a test drive and she was flying again...until the dam thing slipped back off. So tomorrow im going to buy another hose and replace it.

Honestly though, this forum is the best hands down. Thanks everyone for there input!

 

[killer_eclipse]

see thats why i alway do my own work when possible and when not i still double check the shop.... but what turbo are you running?

 

[Cesarlcase]

see thats why i alway do my own work when possible and when not i still double check the shop.... but what turbo are you running?

Probably the best thing to do because i ran into this problem before with a mechanic. My car was overheating and he was considered reputable...told me that my water pump was no good, i did some research and concluded it wasn't the problem and in fact it was a radiator saved me about 460 bucks!! I'm running a t3/t4 garrett turbo. Looking into getting it tuned now.