squealing and wont build boost

[unlmtdndeavor]

i just installed my supra side mount and was logging my car up and down the street, getting ready to adjust my fuel on my safc. after about 5 runs, car holding 15psi on the 14b and spiking to 17. on my last run i develop a loud squealing when i try to boost. it gradually get louder with more throttle and will not allow me to build boost. i tightened all my couplers and transition hoses and everything seems tight. my lower and upper i/c pipes are all solid welded. i have not had a chance to check the turbine wheel for play but i will tomorrow. i searched but it seems as if anyone that has had this problem has not found an answer or hasnt posted it. any help would be great, thanks

 

[DSM90AWD]

Sounds like a boost leak to me. Try pressure testing your intake from the turbo inlet.
Could be a vacume line blew off, throttle body seals leaking or BOV (recirculated right?)

 

[unlmtdndeavor]

im going to pressure test as soon as i get a chance to. im about to take a look at the turbo in a minute, i'm hoping for the best. ill check vacuum lines also. and yes, my bov is recirculated. usually a boost leak makes a loud whoosh...not a scream though....

 

[tselling]

It could be that you aren't getting any oil, or coolant to the turbo. Check to see if the oil feed line is leaking or if it is clogged. It deffinately sounds like it has something to do with the turbo. but i would still check to see if it is a boost leak, and check for shaft play also.

 

[Nanan]

i just installed my supra side mount and was logging my car up and down the street, getting ready to adjust my fuel on my safc. after about 5 runs, car holding 15psi on the 14b and spiking to 17. on my last run i develop a loud squealing when i try to boost. it gradually get louder with more throttle and will not allow me to build boost. i tightened all my couplers and transition hoses and everything seems tight. my lower and upper i/c pipes are all solid welded. i have not had a chance to check the turbine wheel for play but i will tomorrow. i searched but it seems as if anyone that has had this problem has not found an answer or hasnt posted it. any help would be great, thanks

That basicly sounds like what my T25 did when it died, it would squeek and chirp on startup and make a screeching sound on 5+psi boost but that was about as high as it would go. The T25 had a crapload of shaft/end play and the compressor blades were all chipped up so I had FP turn it into a T28. Now after 3 years of driving my turbo is starting to do the screech thing under boost again. I think its Evo3 16g time.

Check the shaft play on your turbo, my guess is the bushings are shot and its time for a rebuild or replacement.

 

[unlmtdndeavor]

didnt get to do a boost leak test yet, all the tire shops were closed so i couldnt get my hands on a valve stem.

there is barely any shaftplay in the turbo. it is definately within the limits of how much it should move. the fins do not seem to hit the side of the compressor and the fins are not banged up. maybe the turbo could be oil starved...how do i check?

 

[tselling]

Ok it is an easy task but it is very IMPORTANT that you follow my directions exactly on this or else you end up with a bigger problem than you want. you need 2 tools 1.) 17mm socket w/ 1/4in drive ratchet. 2.) 22MM wrench. first you want to take the banjo bolt off the bottom front left of the head. it is connected to an oil feed line that goes to the turbo. check to see if oil is leaking out. if so then next try to plug that hole so you dont loose all your oil. DO NOT USE THE BANJO BOLT. use something no longer than a 1/4 in long, and not another bolt. once you have that off grab the 22mm wrench and take off the other end of that oil feed line connected to the top of the turbo. make sure not to loose any of the washers, on either bolts , as they are hard to replace. next, you can blow through the oil feed line to see if it is clogged. if not then you have another problem. Now there are 2 sets of washers one set for the 17mm bolt that goes to the head and one set that goes to the 22mm banjo. make sure that you have all these parts when you put it back together. Now here is where i am going to stress this ALOT. DO NOT OVER TIGHTEN THE BANJO BOLTS WHEN YOU PUT THEM BACK ON!!!! DOING THIS WILL STRIP OUT THE THREADS IN YOUR HEAD OR TURBO you should only tighten them 1/4 - 1/2 turn more than hand tight.If it leaks then just tighten it 1/8 turn more till it stops leaking. and again make sure that you have the washers on both sides of the line. good luck and i hope this helps
-Thomas

 

[tselling]

Oh the reason that is is squealing like that is, %90 + on this, because it is blowing hot air through the turbo. if it has a good supply of oil and coolant, there should be a coolant line too in front of the oil line on the front of the turbo, then i would start checking the smic to see if the fins on it are all in good shape. and when you take off the oil feed line there should be coolant in the turbo too. this is all based on a 14b turbo but i am assuming that the one that you have is a 14b or similar.

Post results when you get this fixed and let me know if this helps and if it cured your problem.
-Thomas

 

[unlmtdndeavor]

ok. i didnt get to taking the turbo off completely. the fins are fine as i suspected. the turbo is not blown, oil is getting to it. the reason is there was a leak in the intercooler, nothing some jb weld can't fix. it wouldnt hold any boost, i guess the old owner had put a dent in it. ill let you guys know tomorrow how it turns out. im gonna port my manifold, o2, and turbo while im at it.

 

[unlmtdndeavor]

i fixed the leak in the intercooler, leak tested it and it holds boost fine. the fins on the turbo are also not bent or anything compressor or turbine side. one thing that i realized last night was that the lapper doesnt completely seal the hole. it seems to be off center. i believe that this may be the problem as air is escaping through the hole and not allowing it to build boost, thus when a high amount of air is sqeezed through that hole, it will result in a high pitched sound. i'm going to pull it right now and see what can be done with it.

 

[unlmtdndeavor]

well i checked it again and it seems as if it is off by just a hairline. i shined a light and i could barely make out a hairline, which doesnt seem to me that it would make enough of a leak to create a no boost scenario. so is my turbo blown? time to upgrade?

 

[Defiant]

Tighten your power steering belt.

 

[unlmtdndeavor]

im pretty sure its my turbo. a power steering belt wouldnt make my car not boost. i checked my turbo again, and there is some endplay...so thats the end of the turbo. if anyone has a spare 14b, id like to purchase it. thanks