alright everyone quick question. so having a little fun earlier tonight all of a sudden the turbo on my 04 sti started making an extremely loud hissing noise after 10psi and would only go to 15psi at wot(normally18psi) not experiencing knock or anything like that and have good oil pressure and no visual oil leaks of any kind. I'm guessing my turbo is now shot but figured id ask all of you fine people on here if that is the case that my turbo is shot. thanks in advance Travis
turbo question
- Thread starter t-rex sti
- Start date
HolyCrapItsFast
Drinks beer!
Sounds like the coupling is loose after the turbo. Check for leaks around the turbo outlet area and the intercooler. spray some carburetor cleaner around and listen for changes in engine speed at idle. It is likely that the leak occurs only under pressure so you may need to perform a boost leak test.
If it wasn't for the hissing noise, I'd think the turbo might be cracked on the hot side as many of them do (right around the wastegate port). HolyCrap is probably spot on with the turbo-to-IC coupler suggestion. Have you removed the intercooler recently for any reason? Also, no need to do this right now, but next time you remove the downpipe, I'd highly suggest inspecting the hotside near the wastegate port. You'll need a bright light and sometimes even a magnifying glass. The crack can be so small and closed up tight that you would never notice it until the turbo is really hot and the crack expands. Back in the day, when it happened to my VF39, I'd hit full boost just fine until the car was running for 10 minutes or so and then I'd only make about 14 psi (target was 20 psi).
HolyCrapItsFast
Drinks beer!
I would think so if it stayed at 10psi, but it does go to 15psi... which when I think about it, is target for a stock car. I would wonder what he is targeting if 15psi is low. :tup:
I would have to agree with @HolyCrapItsFast hissing sounds is almost a sure fire sign of a boost leek and as stated you may need to do a boost leak test. If you have any questions on how to check this let us know and well give you information where we can.
sorry guys haven't been on in a few days. didn't notice the first time during daylight but after a second look i noticed that the clamp holding the coupler from the tb to the intercooler apparently came loose and blew off partially. thanks for the help i do greatly appreciate it and also have brand new silicone couplers and t bolt clamps arriving tomorrow since the stock ones are pretty beat up. again i thank everyone who commented and helped!!!
Good call on the new couplers and clamps. :tup:
