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Discussion Starter · #1 ·
ok well ive just started noticing this and im at a loss for ideas of what it could be. when i accelerate and get it up to about 4500 rpm's it makes this VERY loud screatching noise. it sounds like those old POS cars when they first start up like they're belts make that loud screatching sound, well it sounds like that but only after 4500rpms...whats up?

Discussion Starter · #3 ·
the loose belts would cause that loud screatch at only that specific rpm range...i would think if they were loose theyd start screatching way before then

Discussion Starter · #5 ·
hmm i do run open downpipe alot but i also have had some suspision of my turbine being burned, because when we were replacing my AFM a while back my friend who also owns an mk3 spun my turbine with his fingure and it wanted to slow to a stop almost half way around. like it wasnt a smooth turn. i also had the suspision because i ran the car with no filter down the street to see if my turbo was spooling fine and i could barely hear it like im not sure if that may have something to do with it

Go All Electric
1,183 Posts
Red '88T said:
start lookin for a turbo...
Yup. Seems like the compressor wheel is rubbing against the housing. If there was that much resistance that it wanted to stop spinning after about 1 turn .. it probably has so much resistance that it wont spool until about 4500rpm .. and when it does spool you hear the scraping. My best guess .. but no promises.

Discussion Starter · #9 ·
crap! i was afraid of that....CRAP!....would this also have some reason for a stutter.. like a miss in acelleration because heres the whole story. i was taking out various parts oh my car to see what i can loose and what i can keep ya know and the honey comb mesh part in the AFM was damaged so the car stutttered and missed like crazy when i was accellerating. so oviously i knew that was the reason for it so we replaced the AFM sheel with the honey comb mesh part in it. but we kept the AFM senor and just put it in the new shell.. it stoped the visious missing but left one or two soft missing in each gear...thats when i noticed the can this all be linked? new turbo will fix my problems? because honestly the car is MUCH slower than when i first bought the car and i can seriously tell that now. please i need some serious help, if you need to ask questions to find answers please ask

Go All Electric
1,183 Posts
Thi Experience (2:00:55 AM): hi, my names cruzmoreno, im from SF i was having trouble with screatching noises with my car
AWIDESUPIE (2:01:18 AM): Multi tasking now. Yes.
AWIDESUPIE (2:01:37 AM): ?
Thi Experience (2:01:48 AM): multi tasking?
Thi Experience (2:01:52 AM): i dont understand
Thi Experience (2:02:24 AM): are you bussy? im sorry i can talk to you a lil later
AWIDESUPIE (2:02:33 AM): Me .. multi-tasking .. talking on phone .. computer .. taking pics of a bumnch of stuff I want to sell .. getting ready t goto bed to wake up early =Multi-tasking.
Thi Experience (2:02:46 AM): ahhh
Thi Experience (2:02:49 AM): hahahaa
Thi Experience (2:03:05 AM): ok well ill try not to be too confusing
AWIDESUPIE (2:03:06 AM): I'll talk though .. just letting you know.
Thi Experience (2:03:09 AM): ehh so you think its my turbo
AWIDESUPIE (2:03:18 AM): that's what I said.
Thi Experience (2:03:27 AM): crap
AWIDESUPIE (2:03:32 AM): posted it at sf.
Thi Experience (2:03:35 AM): yea
AWIDESUPIE (2:03:43 AM): nothing to worry about if you got the dough.
Thi Experience (2:03:44 AM): what do you think could have caused this
AWIDESUPIE (2:03:55 AM): how many miles on the turbo?
Thi Experience (2:04:00 AM): about 16k
Thi Experience (2:04:02 AM): its rebuilt
AWIDESUPIE (2:05:12 AM): ... well then .. IF it is your turbo .. whitch it prob is since it isn't spinning freely when you friend tried ... I would definitely say that it is your builder's fault and that I hope you have some sort of warranty.
Thi Experience (2:05:32 AM): hmm
Thi Experience (2:06:03 AM): well i bought it from a mechanic at toyota and he had it rebuilt at majestic turbo and i have all the papers and all but i doubt its under warentee still
Thi Experience (2:06:27 AM): crap
AWIDESUPIE (2:06:28 AM): You did say that your friend checked the turbo recently, after the rebuild , right .. and that it would barely spin at all .. correct?
Thi Experience (2:06:37 AM): yea
AWIDESUPIE (2:07:39 AM): A compressor wheel a(cold side) and or turbine wheel (hot side) should spin very very freely .... it should be so smooth .. almost not explained any other way.
Thi Experience (2:08:05 AM): yea i know
Thi Experience (2:08:13 AM): when i first bought it it spun quiet freely
Thi Experience (2:08:48 AM): infact when i had shimmed the wastegate for the first time i spun it and it spun about a whole rotation after i took my fingure off
AWIDESUPIE (2:09:29 AM): Well if you know .. then why are you asking ... if your turbo is having problems if you know that it should be sinning freely? (no offense .. but really) Do you remember if you friend noticed if the compressor wheel was rubbing against the housing at all?
AWIDESUPIE (2:10:02 AM): Since the exh side and the cold side are linked by a shaft ... one being bent/scraping would slow done the other.
Thi Experience (2:10:10 AM): no he only said that it felt like it make have been burned because it wouldnt spin freely
AWIDESUPIE (2:10:18 AM): burned?
Thi Experience (2:10:26 AM): thats what he said
Thi Experience (2:10:59 AM): the thing i really need to know is, is it better to get it fixed or to just get a whole new one?
AWIDESUPIE (2:11:06 AM): H emeant that literally or is burned some word like "toast" etc as in the turbo is "blown"/broken?
Thi Experience (2:11:30 AM): like it may have acually been burned like one of the sides or something
Thi Experience (2:11:43 AM): because it felt like it was being slowed down on one side of the rotation
AWIDESUPIE (2:11:53 AM): Whether you should et it fixed or buy a new one is dependant on the extent of damage to current turbo and on your goals for power for your car.
AWIDESUPIE (2:12:15 AM): Thi Experience (2:11:30 AM): like it may have acually been burned like one of the sides or something
Thi Experience (2:11:43 AM): because it felt like it was being slowed down on one side of the rotation
AWIDESUPIE (2:12:23 AM): that makes no sense to me
Thi Experience (2:12:58 AM): he basically said that the housing may have been burned because it felt rough when he spun the wheel
AWIDESUPIE (2:13:31 AM): ugg .. that would be due to friction .. as in the wheel may be rubbing against the housing.
AWIDESUPIE (2:13:46 AM): to answer your question and get some closure to this ....
AWIDESUPIE (2:14:01 AM): AWIDESUPIE (2:11:53 AM): Whether you should et it fixed or buy a new one is dependant on the extent of damage to current turbo and on your goals for power for your car.
Thi Experience (2:14:08 AM): ok
Thi Experience (2:14:40 AM): tomarrow i will open it up and see
Thi Experience (2:14:58 AM): but in the mean time it probably wont be good to run the car under boost until this problem is fixed
Thi Experience (2:15:03 AM): correct?
AWIDESUPIE (2:20:11 AM): sooo .. you need to know the exact damage if there is any .. which it really sounds like there is ... and or you need to know what power levels yu want to reach in the future. You could rebuild the ct26 turbo stock for the same price as upgrading the wheels inside it for better performance. You need to have the turbo built at performancetechniques ... accept no substitue .. if yu want to build a ct26 ...they aev THE most reputable place. No .. you should not try to boost with the car ruinning as is. Did you check you belts at all yet about the noise? Belts are still possible. Also .. about taking the turbo apart yourself .. be careful. Don't expect the person/shop tat you had build it 16k miles ago be willing to help you out if they know that you took apart the turbo yourself. To what extent ae you talking about dissembling the turbo? Yuo may want to get into touch wiht PT and ask if they will give you a free inspection if you want the tubo completely torn down and inspected by a knowledgeable persohjn/business. To check turbo specs/condition your self .. use : . Tihs is from an MR2 page but it is the same turbo. Your turbo s a stock build .. correct? No mods to it?
Thi Experience (2:21:44 AM): yea no mods
AWIDESUPIE (2:22:00 AM): k ..but did you understand what I was saying?
Thi Experience (2:22:14 AM): yea
Thi Experience (2:22:20 AM): so one question
Thi Experience (2:22:48 AM): for the same price i can have an upgraded ct witht he problem fixed, than to just get it rebuilt to stock build
AWIDESUPIE (2:29:15 AM): TMK .. yes. Should be about 450$ from PT .. either way ... not positive though .. but more things to consider. Is your tubo in a good enough condition t be rebuilt .. or do you need to buy a new one? Also .. what is your budget like? If yuo need a new/used turbo .. most sell on forums for about 100$-300$. You may also want to keep you eye out for upgraded ct26 sales on the forums/ebay/parts trader etc. Also .. if you decide n an upgraded ct26 .. you want to make sure that you have necessary supporting mods for the extra flow which would be dependant on what boost levels you would be running with the upgrade. The upgrade will flow more and therefore pull in more air and require more fuel and require better exhaust flow etc to be efficient .. and the point at which you eed more fuel and exh flow and air flow and fuel cut raised etc etc .. come at a ower psi than with the stoickl ct26 .. so there is a lot to consider.
AWIDESUPIE (2:29:48 AM): Follow me at all?
Thi Experience (2:30:04 AM): ya
AWIDESUPIE (2:30:08 AM): Cool. I dunno a whole lot about turbos . but I know enough to get you this far for sure ... you may want to post on forums ... in fact .. I will copy paste this there when we stop probably .. in order to, potentially, help you more.
Thi Experience (2:30:24 AM): hahah
AWIDESUPIE (2:30:27 AM): Anything else?
Thi Experience (2:30:28 AM): alright
Thi Experience (2:30:29 AM): thanks
Thi Experience (2:30:31 AM): nope
Thi Experience (2:30:34 AM): thanks for your help
AWIDESUPIE (2:32:10 AM): Alright then. No prob. Glad I could help. Will copy and paste to se if anyone has something to add. You really should ask your questions on the foums. That way there is more than one person seeing them and a lot more qualified ppl can answer your questions. The only time I use aim is when I know there is something specific that the person has an experience with that nobody else would know about etc .. if you follow.
AWIDESUPIE (2:32:18 AM): My best regards to you.
AWIDESUPIE (2:32:20 AM): God luck
Thi Experience (2:32:24 AM): thanks
AWIDESUPIE (2:32:26 AM): Good luck*.
AWIDESUPIE (2:32:47 AM): God's luck could help you too though ... *wink*.
AWIDESUPIE (2:32:52 AM): :-D
Thi Experience (2:32:58 AM): hahaha
Thi Experience (2:33:07 AM): ill need all the help i can get trust me
AWIDESUPIE (2:33:11 AM): OK then. G'Night.
Thi Experience (2:33:23 AM): see ya

Discussion Starter · #13 ·

(1)Look to see if there is a standing puddle of oil on the turbo intake. MR2s naturally have a little oil here from oil/oil gases that came out of the PCV pipe from the valve cover. During Hard right hand cornering oil will shift to the left of the head and leak out the PCV into the intake tube. Many have replaced this tube with a K&N Vented Catch can to reduce this, but that's another discussion. Now, back to that puddle (if you have one). NO OIL - to maybe a 1/8"-1/4" puddle is probably normal. Puddles larger than this indicate either medium-hard cornering during your last drive, or that the oil seal(s) on the compressor side of the turbo are leaking.

thats from the site above....thats whats happening to my turbo acordian pipe has in it...omg..i swear this thing is completely messed up

Discussion Starter · #14 ·
omg...that website told me all of my problems...and the stock boost for an 87 turbo is supposed to be 6.8? right? like its supposed to read that on the gauge? because it reads only close to 5.. but it only starts screatching after around 4500

Discussion Starter · #17 ·
lol!!! hahahaha yea im pretty sure its gotta be rebuilt. hahaha but honestly when the car was for sale it was fine, but yea i guess time only shows how crappy of a job some ppl can do when it comes to rebuilding

the clever guy
782 Posts
like its supposed to read that on the gauge? because it reads only close to 5
Now, I've never experienced a turbo where one, or both, of the wheels is/are contacting a housing but I would think that it wouldn't be capable of producing positive manifold pressure if that were the case. Can someone clarify this for me? Also, the stock guage is notoriously inaccurate so 5 psi on that guage could be 7-9psi in reality. Also again, the stock ct spools (reaches max wastegate allowed shaft speed/load) between 2500 and 3000rpm and I would think that if there was a problem it would appear in that range and not "wait" until 4500rpm. Did you check your belts just to at least eliminate that possibility?

Go All Electric
1,183 Posts
Like I said ... I dunno a WHOLE lot about every piece included on a turbo .. but I can see how it would take more air/rpms to spool a turbo that was being slowed down by extra friction ... because it's physics. Therefore .. the wheel(s) may not be spinning fast enough until ~4500rpm to make the "screeching" noise. BUT .. I have never seen this turbo .. and know nothuing about it. I make it evry clear that this is my hypothesis and that there could be other problems. Regardless ... good luck.
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