Turbo spins freely but no boost! Options

[celi_6]

Hey guys, I have an issue with my 2nd gen 3sgte motor. I purchased an exhaust manifold from ebay and put it on. I screwed all the nuts and bolts back on but i was missing a nut holding one of the six bolts holding the turbo exhaust housing to the downpipe. I figured that it'll be okay since it looks tight enough. I drove the car for about 4 blocks and i started to lose power, so I decided to go back home. When I got back to my garage, I started to hear knocking noises coming from my engine and it sounded like it was coming from the head. A few days later I went back to start it up, the noise was gone but still no power when accelerating and white smoke comes out from my exhaust when when accelerating. Car starts up perfect, car idles fine, don't hear any boost leak and no smoke coming out from exhaust during idle. Did a compression test and it came out 150 155 155 150, so I assume that head gasket is good. Checked sparks plug and they all look good, no oil. Wastegate acutuator arm is not loose and turbo spins freely with no shaft play. Took apart all IC pipings and reinstall about 4 times to make sure it is not loost or damage.

Here are some more problems I encountered:
1. When i'm in first gear, i floor the car, the boost gauge needle would jump to 0 psi and drops instantly. happens in all gears.
2. Took off the filter by the maf and when i rev, I feel/hear it sucking
3. Don't hear BOV ( vacuum leak?) I have a Greddy BOV
4. Before the car had this problem, during boost, the green LED knock lights would come on but now, it just stays red.

What could be the reason for my car not to boost? Before I installed the new exhaust manifold, car ran great at 14psi.

[domyz]

the wastegate don't look like to seat in place

it's 99% sure that you have


Boost leak
OR
a non closing/seating wastegate
OR
a bad turbo

remove the downpipe and look if wastegate close freely and seals the exhaust bypass
and a free spinning turbo don't means that the ceramic turbine hasn't been destroyed
Check your intercooler, intake manifold gasket for leaks

This post has been edited by domyz: Oct 5, 2009 - 3:22 PM

[95st-celica]

pull your downpipe off....lay your gasket over the downpipe, you will see that there is more metal around the opening of the downpipe that you have to grind out so that it is even with the gasket...the downpipes from ebay have to small of an opening and need to be ground down, they actually hit the wastegate and keep it open....im not saying this is your problem but it defentially well could be

[celi_6]

I will look into it tomorrow and what the problem is. Thanks guys

[bccentaur3]

If you've got a massive boost leak you wouldn't see boost period. I've experienced this on my 5sfte set-up before. Now in your case it can't be caused by a boost leak, because when I had my 3s and my piping blew off, the car wouldn't idle at all. If there are any big leaks at all the 3s would not run. I'm thinking you could have a bad knock sensor, but then again you heard a knocking noise.

[celi_6]

If you've got a massive boost leak you wouldn't see boost period. I've experienced this on my 5sfte set-up before. Now in your case it can't be caused by a boost leak, because when I had my 3s and my piping blew off, the car wouldn't idle at all. If there are any big leaks at all the 3s would not run. I'm thinking you could have a bad knock sensor, but then again you heard a knocking noise.

My safc is still reading the knocks, does it still mean that my knock sensor is still working? I have no check engine light too. Could it be my MAF causing my boost not to peak over 0 psi?

Haven't had the time to check my car yet but I will check it this weekend.

[x_itchy_b_x]

My guess is that the turbo shaft between the intake and exhaust housings snapped. I've done that before, same symptoms as you.
let us know your finds.

[pittfirefighter]

i agree with itchy... take the turbo all the off and check both sides

This post has been edited by pittfirefighter: Oct 7, 2009 - 6:03 PM

[bccentaur3]

what was the temp outside when this happened?

Check your afm just to see if the flapper is stuck wide open. If thats the case you won't be able to drive the car for sh!t.

[celi_6]

Found out why my car wasn't boosting. Finally had the chance to work on the car this weekend and found out that the fins on the exhaust side of the turbo were broken. Bought a new used ct26 turbo and will have it install within two weeks. I will let you all know the results.

[celi_6]

Finally install my new ct26 turbo and every thing WORKS!! Boost felt soo good!! The whole reason why my turbo wasn't able to boost over 0 psi was my broken fins.

[Bigblock]

TUUURRRBOO!!
We're supposed to get 3"+/- tomorrow here. You guys drive turbos in the snow??

[celi_6]

TUUURRRBOO!!
We're supposed to get 3"+/- tomorrow here. You guys drive turbos in the snow??

My car hibernates in the garage during winter. The turbo issue happened this past fall but never had the chance to fix it until this past weekend. If it was a GT4, it would probably see snow.