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Destroyer of Turbos
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4,461 Posts
Discussion Starter #1
ok guys i did a search and heres what i got:
link 1
Link 2
Link 3
Link 4 Link 5

Links 4 and 5 are the most accurate of what I am experiencing. I have a stock 91 turbo w/ a 5spd. Today when i got in the car after work and let the car warm up i went and punched it. boost had come up fine in 1st gear, exactly to where it should on the stock boost guage. then in 2nd in the upper rpm i heard a whinethat was coming from the turbo that wasn't normal. link 4 accurately describes it. was only at WOT and only in the very upper band of the revs (4750-5500ish). it didnt do it on the way to work. tomorrow ill check for shaft play but when i had the intake apart less than 1k miles ago it was just normal. i check my ic pipes on what is starting to approach a regular basis now and no praws. im gonna check the exaust stuff but not sure what to look for on there. help! all those threads didnt have a conclusion as to what the praw was and since all the treads are over a year old i doubt they remember what it was...lets see what u guys can come up with :)
 

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My guess, did you check the connection at the accordian pipe. if it's loose or cracked it may be causing the whine by sucking in more air through a smaller area. also check the shaft play while your there.
 

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the clever guy
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782 Posts
Wow.....I DARE someone to say 'search'. How loud is it? How, and what kind, is your oil? Only in second gear? Answer these and we'll go from there since i am stumped. Maybe someone else knows. Noises are very hard to diagnose without actually hearing it.
 

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Destroyer of Turbos
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4,461 Posts
Discussion Starter #4
Boostedstr8six said:
Wow.....I DARE someone to say 'search'. ... Noises are very hard to diagnose without actually hearing it.
lol thanks man... i try and be through before i post something so its not a repost...im driving back to dallas tomorrow so ill try and get a few sound clips of it and ill try and check the accordian hose before i start out. i went back out after i posted to try looking but its raining and the motor is still too hot :( so tomorrow.. keep the ideas coming guys!
 

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I have a very similar sound. I think it is a boost leak, I need to pay and get all new toyota hoses for isc bov, accordian hose, and some ic hardpipes.
 

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You know, I started to notice that same noise too and was almost positive my 15K mile ct26 upgrade was done for -- but I do have a minor exhaust leak at the turbo to turbo elbow connection. I'll be pulling it off this weekend, cleaning up that metal gasket, and using some copper spray -- I'll report back if it makes a difference
 

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probably not your problem but when I first changed my air filter the accordian hose cracked and the turbo sucked a huge chuck of it into the impellers i was fuckin pissed
 

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Destroyer of Turbos
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4,461 Posts
Discussion Starter #8 (Edited)
ok i think i can fully kick the turbo out as the problem... after a 3 hour trip home i narrowed it down. here is exactly when it happens:
5k-5500 rpm in 1st and second gear @ WOT ONLY after the car has warmed up but only for about 30 mins. after that it went away. sorry bout the recording but i wasnt able to get a good cut that didnt sound like anything but engine noise. it sounds like agrinding noise and i noticed my oil pressure dropped when i was at WOT and other high throttle position. it would drop from 40lbs^2 to between 40 and the next hash so im going to check the oil tomorrow..i know im due soon (less than 600 miles) also i dunno if this helps i noticed a signifigant (sp) amount of oil SEEPAGE around the valve cover gaskets, which i know needed to be replaced but there seems to be more so that may account for the oil...ideas after the update?
 

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Destroyer of Turbos
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4,461 Posts
Discussion Starter #9 (Edited)
ok fixed the praw...when i was driving home i noticed the oil guage was reading low..and when i accelerated it would drop lower. it was at about 40^2 maybe a little below and then when i opened the throttle it dropped bout 1/2 way down the dial..so when i got to dallas i added oil... the oil plug gasket was a wreck and had leaked 2 quarts out... got an oil change, replaced the gasket and boosted...no praw...doh! i got lucky...2 quarts in a week (the last time i had checked it, less than 100 miles driven)..well theres another way it could make that noise i guess :) glad its fixed...feel really dumb that it was something so normal that should have been checked


edit: jsut got back from dropping off the gf and the car was semiwarm again (the temp guage just regestered normal heat and the climate control was kickin out 85 degree air) ..the sound is back..and this time it starts @ 4700 rpm and conts to 5250rpm...wtf?! im pulling the valve cover gaskets apart on monday to replace them so ill see what i can find in there...
 

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JDMSoopraDriftoMachine!!1
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925 Posts
Mine does it as well... I'll just say its the weather.

But its a shrill whine at the upper end of the tach when boosting long... yep.
 

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DFWSupras
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1,627 Posts
Hey Joe last time I saw your car. I heard an exhaust leak. I'm putting my money on your turbo to manifold gasket. Danny's Car made a wierd sound close but not exactly like a whinning Turbo. Check for loose bolts and nuts on the exhaust side. Same goes for you Drew and yes might be the sudden change in temperatures.
 

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Destroyer of Turbos
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Discussion Starter #14
damn it christian more stuff to add to the list that i might beed to fix! lol the old chevy i have had an exaust leak..ended up clogging the cat...well i guss it might result in me getting that HKS 3in hi-flow exaust i wanted.... :) ill check it tomorrow
 

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dude mine was doing the same thing check ur intercooler piping, mine is aftermarket know and when i hit 4000 it would do the same thing... come to find out it was the lower intercooler piping off the cold side of the turbo fell off and wasent boosting as hard as it should have been... good luck man hope that helps
 

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Destroyer of Turbos
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4,461 Posts
Discussion Starter #16
pulled the intake apart between lunch and a class...checked the turbo, no play up down...very little front and back..like almost none. checkin the ic pipes too... c-man im gonna post up a pic then of the turbo exaust side to dp..tell me what u think..
 
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