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Weird Turbo noise

5K views 28 replies 9 participants last post by  VintageFD_ 
#1 ·
today i was revving my enigne to about 4.5K rpm and noticed the turbo noise is or evident, sounding kinda weird. I have intake btw. Then i started driving and noticed the turbos were making a blender noise when spooling up. Its pretty loud and i have no idea what it could be. turbos has 122k miles on them and the motor has 5k miles on them. I hope the turbos arnt giving out!!
 
#3 ·
lol no i have one. i also have a Rx7 and am used to reffering to 2 turbos.

I HOPE MY TURBOS ARNT BROKEN!!!! please say there might some other issue thats not so serious!
 
#5 ·
the sound the turbo is making is very hard to describe. I guess blender is not a good way of describing it. Its making a higher pitched louder, less smooth sound. Its heard more when its spooling up and is gone when at full boost.
 
#9 ·
Ok well 'blender sound' doesn't really explain it. Are we talking about blendie a smoothie, chopping ice, running an empty blender, etc?? I guess we can assume though, that the car hasn't made this noise before? Any increase in noise during spool up should be monitored carefully. If there's no grinding, it could be as simple as a hole in your exhaust. But one large enough to greatly increase spool up whine would tend to significantly affect the turbo's performance. So I don't know... I wasn't able to wear out the turbo in my '87 even at 330k miles.
 
#10 ·
What *should* they sound like exactly?

Mine whistles gently at low rpm and goes away like he describes, but the wheels aren't hitting the housing or anything nasty sounding. My friends 900T did the exact same thing and he said has done for ages.

Boosts fine, so i'm guessing it's all cool. Although my friends 323GTX whistled and then went kaput in a cloud of white smoke, that had shaft play though. :(
 
#11 ·
FruitLooPs said:
What *should* they sound like exactly?

Mine whistles gently at low rpm and goes away like he describes, but the wheels aren't hitting the housing or anything nasty sounding. My friends 900T did the exact same thing and he said has done for ages.
That sounds totally normal to me. I suspect the audibility depends on which turbo you have, and which intake/exhaust modifications have been done, if any.
 
#12 ·
VintageFD_ said:
today i was revving my enigne to about 4.5K rpm and noticed the turbo noise is or evident, sounding kinda weird. I have intake btw.
If this means you have a modified intake, you may be hearing normal noise, but louder.
SAAB put a lot of effort into intake noise suppression.
 
#13 ·
The noise for sure is not the same as before with intake. Im not dumb to put a intake and then be scared that the turbos are louder..

Anyways, the turbo noise sounds kind of like a blender blening nothing added untop of the normal turbo noise. Its alot more hissy and raspier. I dont think a sound/video clip will make a difference because the noise quality is so bad that it will sound normal. Its not VERY different from before, but 100% sure there is something wrong and i want to get to it before its to late.

I think a bearing sounds like a prob that would make sense. The turbo noise is less smooth, and a bearing is something that could be reasponsible for that. but then again, should a bearing go out at 122k miles.

I also think that this prob accured DURING the reving i was doing. I was revving and then noticed a change. I wasnt reving very high, and the motor was warm, not full opterating temp tho. I understand this prob is very difficult for u guys to figure out because of the lack of information and description, any help would be great, THANKS!!:p also anyone in the L.A region, i would be more that happy to drive and show you in person what im talking about.
 
#14 ·
ok, today after driving for 20 min, i was barely boosting. the raspy noise was even louder and much more raspier. I babied it home, and tried WOT and it boosted almost fully with less of the raspy sound. The raspy noise is much more noticable under WOT, but after letting the car chill, it goes away to almost nothing but after some WOT runs it comes back. :roll:
 
#16 ·
Jim Mesthene said:
If it boosts, doesn't leak oil and the shaft doesn't wiggle, there's not much you can do.
Could the raspy noise be a pressure leak?
I dont know, the boost comes and goes. I think something is loose, but dont know exactly what. This weekend im gonna jack up the car and go under to check things out. Hopefully its just a loose bolt.
 
#17 ·
I had a similar problem as y the one you describe. It turned out one of my bearings was so worn and clogged that it cracked, and the other one was very worn. I would suggest taking the intake pipe off, and feeling for play - that is up and down, and in and out. Oh and there wasnt any smoke at first when i heard this "whoosing, wirring, grinding, noise," but after a little while the smoke came and lots of it!!

So pull the intake pipe and check for play, it will take 5 minutes max.
 
#18 ·
cotton42090 said:
I had a similar problem as y the one you describe. It turned out one of my bearings was so worn and clogged that it cracked, and the other one was very worn. I would suggest taking the intake pipe off, and feeling for play - that is up and down, and in and out. Oh and there wasnt any smoke at first when i heard this "whoosing, wirring, grinding, noise," but after a little while the smoke came and lots of it!!

So pull the intake pipe and check for play, it will take 5 minutes max.
thnx, so take the intake off and feel play where? if i take of the intake im just gonna feel the turbo fins i think.
 
#19 · (Edited)
The simple answer is, essentially, so what. The turbo has one moving part, the shaft. It is suspended in bearings by an oil film. If you have oil pressure then there is no preventative maintenance that can make any difference to your turbo if it is already failing.

They don't wear in the normal sense. They work really well right up to the point they stop working at all.

With turbos you feed them oil (and coolant if they have water jackets), you don't spin them up when the oil is cold and you let them spin down when the oil is hot (turbo heated from boosting and spinning fast). They then basically last forever unless a seal fails or a turbine or compressor blade fails.
You cannot "repair" a turbo you must rebuild them. So, you basically drive until the oil consumption or the noise become unacceptable and then replace with a rebuilt unit or get yours rebuilt.

My money is on an exhaust leak or an intake leak with the smart money on the intake side.
 
#20 ·
Superaero said:
The simple answer is, essentially, so what. The turbo has one moving part, the shaft. It is suspended in bearings by an oil film. If you have oil pressure then there is no preventative maintenance that can make any difference to your turbo if it is already failing.

They don't wear in the normal sense. They work really well right up to the point they stop working at all.

With turbos you feed them oil (and coolant if they have water jackets), you don't spin them up when the oil is cold and you let them spin down when the oil is hot (turbo heated from boosting and spinning fast). They then basically last forever unless a seal fails or a turbine or compressor blade fails.
You cannot "repair" a turbo you must rebuild them. So, you basicaly drive until the oil consumption or the noise become unacceptable and then replace with a rebuilt unit or get your rebuilt.

My money is on an exhaust leak or an intake leak with the smart money on the intake side.
what you are saying makes sense. I agree with you. If my turbo is failing, as u stated it will just be dead, no inbetween. If your right, then my turbo is not failing becomes it works and dosent sometimes. I dont think i have a intake leak because it would necessary affect the boost the way it it. Ill check the exhaust and hope for the best. Could low engine oil cause this, the turbo get oil from the enigne correct, i know this sounds very newbish but to me this makes sense.
 
#21 ·
Raspy tinny noise ???, first off the speed the turbo goes at, if its making this noise I would suspect "Bang" would closely follow.

Under the clutch bell housing where it mates to the engine there is a thin steel splash plate. If this comes loose then it vibrates & makes a sound like you describe at certain RPM
You,ve also got the Cat. heat shield above the cat, or indeed the inners of the cat ( mine rattled about before I removed it)
 
#22 · (Edited)
Norman Lovie said:
Raspy tinny noise ???, first off the speed the turbo goes at, if its making this noise I would suspect "Bang" would closely follow.

Under the clutch bell housing where it mates to the engine there is a thin steel splash plate. If this comes loose then it vibrates & makes a sound like you describe at certain RPM
You,ve also got the Cat. heat shield above the cat, or indeed the inners of the cat ( mine rattled about before I removed it)
If is for sure something related to the turbo. Whenever the turbos spool it makes the noise.... and, i get very little boost, half of normal, and then sometimes it boost normally followed by boost problems again after spooling up several times. I feel like im repeating myself.

im gonna try to post a link to a vid. hopefully it will clearify things.
 
#25 · (Edited)
cotton42090 said:
You should be able to feel the nut on the end of the turbo shaft:cool:. grab it, and try to move it left to right, up and down, in and out.

sorry guys that was the easiest way to explain it :p
Do that, take off the inlet hose and check. Might be hearing one of the wheels hitting the housing of the turbo if there is too much play from worn bearings. :confused:

Friends turbo did this for a while and eventually gave up the smoke, lots of it too. Rebuild the turbo sooner rather than after exploding would be recommended I would think?
 
#26 ·
Superaero said:
How about a big boost leak downstream of the compressor? This might explain why you get intermittent boost. How are the rubber bellows at the throttle housing?


Is your hooter valve OK?

Is your exhaust flex joint holding?
I dont understand 80% of the things you mentioned. Could you explain/describe a little bit what you just said. Im still a newbie:cheesy:
 
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