Jet Engine Noise = No Boost?

[DSMhelex]

ok
ive read a couple threads about a similar problem to mine, but i would like some of you guys to verify that i am correct.
Last sunday me and a couple friends went on a trip and we were doing some crazy interstate driving (80mph+)... well anyway, when i came back to my hometown i noticed a faint whining/jet engine sound. I didnt think too much of it, but as the week went on, it seemed to get progressively worse. First i thought it was my tranny, so i flushed it and put new tranny fluid in it and that was not it. It was hard to hear where it was coming from. Today i got the oil changed just to be sure that wasnt it because i went over my recommended change by a few thousand. Didnt fix it. Just as an experiment i started putting it to WOT to see what boost i would hit and sure enough i only hit 7psi (i usually spike 16 and hold 12).... i did it a second time and i only got 5psi.... and the 3rd i only got 3-4psi. I figured i had a leak. Checked everything and no leaks. Right now, My car is making a VERY loud sound, almost like a jet engine powering up. This is syncronized with the hiss of turbo/boost. I can only hit 3psi now and my greddy bov no longer blows off (not enough psi?), and it seems to be smoking a little bit more than usual (turbo going?). Also, when i rev my car in neutral/park, around 3,000rpms i get a little ticking noise (shaft play?). Im thinking this is a turbo problem. Im still running the stock t-25 and i run stock boost (stock intercooler too) with a full 3" exhaust. A few of my friends (myself included) think its a little wierd that a turbo on a 34000 mile car would go so fast. Correct me if im wrong, but its the turbo going? Any input would be appreciated. thanks.

 

[gsxtacy]

Sounds like a BIG leak somewhere.

Got a boost leak checker?

Do it again.

You know it takes 2 people to check for leaks right?

Pull the inlet off the turbo and check for shaft play.

Then get soapy solution in a windex bottle and pressure the intake tract up from the compressor inlet and spray all the couplers, and Throttle Body. If you still have braided intercooler hose spray it really good.

I am betting its a LEAK, and not a blown turbo.

gsxtacy

 

[Rick4g63]

GSXtasy is correct. There is a huge boost leak. The factory rubber hoses are crap.

- Check all the I/C clamps are tight and secured.
- Check all the rubber i/c hose for cuts. The lower i/c hose to the intercooler has problems to.

I had a problem with boost also. My symptoms were very much similar to yours. After hours of troubleshooting I narrowed it down to the wastegate. I removed the o2 sensor housing and found the flapper had broken off, bt was being "held in place" by the flapper arm. click below the pic on the right is shows the flapper in the closed position (to create boost):
http://www.slowboyracing.com/Porting page/34mm flapper/34mm_flapper.html

I subsequently remved it and had Bunky blow torch weld it. It was T-25 with 89,000 miles when it failed.
Now I have 110,000 miles and she blows like a porno star at 16 psi.

 

[DSMhelex]

ok
i did the boost leak test using this tutorial: http://www.vfaq.com/mods/ICtester.html
i found a small leak in my bov flange, so i tightened it up. Took 'er for a test drive and it was doing the same thing. I'm still hitting 4 psi and im smoking more than monday night bingo. Its hard to drive in reverse because not only cant i see anything (b/c of smoke), i cant stand all the fumes in my face. Its puffing some heavy white/blue smoke now. I'll check out the flapper here tomorrow, but it seems to be getting much worse.

 

[DSMhelex]

Also would like to mention that while i was working on it i didnt reconnect the bov return hose, and after running it i noticed some exhaust coming out of the intake pipe. (the white/blue smoke)