bad turbo or boost leak?

[BlkrwdT]

I just installed a brand new t28 and took it for a test drive. It started boosting as i get on it then at around 4k rpm boost went dead to 0 psi. I've checked all of my i/c couplings and they all look ok. Compressor wheel spins freely and does not rub on the housing. I thought if it was to have a boost leak , I would have atleast have 1-2 psi, but this is zero(via boost gauge) like a N/A car. Car idles and drives perfect , no hesitation ,pop, backfire, just perfect. I dont how to tell any other way if the turbo is broken besides bad seals and shaft play. I checked the wastegate and it seem to be shut really tight . This is making me very fustrated and any help will be very appreciated.

[IanS]

does it still pull hard, or does the car lose power.

[BlkrwdT]

I dont know what you mean but it just drives normal like a stock naturally asperate ka. No boost , no nothing, zero psi.

[IanS]

your wastegate is sticking open, if it boosts to a certain point, then cuts out, Id say check your actuator to see if its working problery. If you had a boost leak it would stumble hard and just run like crap in genral. Even a bad turbo will make boost. Unless its really bad, and believe me, youd know it.

[spider_slayer]

thats not at all what is going on.....reread his post.....he said like an N/A car...no boost at all.....

i'm was having the same problem so i parked my car a little while ago...i could hear the turbo producing boost becuase when i let off the gas it would blow off boost. so that leaves me with a boost leak somewhere.... i'm kinda willing to bet that your turbo is ok, but i really can't help with a problem though seeing as how i havn't been able to fix my issue yet eathier hope someone can help us

[IanS]

if it was an NA car then he would have vacume, and lots of it.

[BlkrwdT]

thanks for the help guys. I took the turbo out and open it up the turbine bearing and seal was siezed as if there was no oil. the compressor bearing was ok although there was alot of oil dripping out when i disassemble it. wierd sh*t. so basically $800 for a trip around a block . CHRA is f*cked, turbine shaft is done.

[kota2240]

how much boost were you pushing? I have a similar problem to yours. It will boost fine until higher rpms and then the boost suddenly dies depending how much boost im pushing. If I push 14psi boost, i hit zero psi at 5k rpm. If i push 7psi then i hit the wall at 6500rpm

[BlkrwdT]

I was pushing ummm 3psi at the most and the turbo went dead. Atleast yours is still boosting. Yours a boost leak most likely or a bad wastegate.

[Hijacker]

check your oil feed line for kinks

[kota2240]

I changed wastegates and used the hks one also. i guess it must be a leak somewhere but at idle it shows nothing. ill keep looking

[IanS]

a turbo car should read between 10 and 14 in HG at Idle

[st33f]

my sr reads 20-22 idle

whats that mean?

[kota2240]

idle should read 18-20inhg (inches mercury) This indicates that you have no leaks.

Anyways i solved my problem with some help from someone who had the same problem.

Lesson learned:: NEVER TAKE OUT THE SPRING IN THE OEM INTAKE TUBE. It was collapsing at high rpms. I installed an aluminum intake and everything is 100%,