Turbo Now Sounds Like A Supercharger And A Hissing Sound In Engine Bay.

[sadr33]

I had a normal Pod filter setup in my R33 Gts-t. Just hanging in engine bay no heat shield. Instead of routing a CAI I decided to try a stock air filter and intake setup.

First few days the car drove fine. No more loud induction sound and no loss of performance, all I could hear is comparatively subtle turbo spool which was mostly masked by induction noise in the past.

Now a few days later I hear a turbo spool in addition to a uncanny supercharger noise whine

The only thing Ive done is took out the pod filter, cleaned the air flow sensor, and fitted the stock intake. I also let someone drive my car unattended out of sight for about 10 minutes which I normally never do.

The car is still boosting what I ask of it according to my guage, which is 6psi stage 1 and 10-11psi stage 2 but it seems a loss of power is becoming more and more prominent in addition to staggered performance. I cant be sure though as this car seems to be very temperamental and is sometimes fast and sometimes barely fast enough to move up a few kph given many seconds ( I think my nismo fuel pressure regulator is not adjusted correctly as well), but I think my turbo is going?....

I have recently did spark plugs and put in new yellowjacket coils.

I also just noticed there is a vaccum leak hissing type sound when you stand over the engine bay as well when the engine is idling. I am very sure this is new.

I checked the hoses and vacuums I can and its annoying I cant find where its coming from.

Anyway Here is a sound clip from inside the cabin, windows closed. Boosting 10psi full throttle, 2 times before 38 second mark, about 65-110kph

At the 38 sec mark popped the car in neutral doing 40 and revved it so you can hear the whine with less road noise

http://picosong.com/33X8/

If got a poor vid of the hissing sound in the engine bay which I'll try post but Im moving all over the place because I was trying to find a good spot.

Anywhere in syd I can get the car casually looked at/advice given without paying for an inspection, Or any friendly members that do it for the hell of it and a pizza + beer like mazda/eunos enthusiasts cos they are such rare breeds ( damn those solenoids and vacuum hoses)

[Moodles2]

Hissing is the sound of vacuum, look at the small vacuum hoses going to the charcoal canister (big black cylinder) and the hose to the factory (map) boost sensor on the driver's side firewall, maybe even the hose to the turbo's actuator. Either a hose has blown off or split

[sadr33]

Will do but I really couldn't see anything broken.

Does everything look ok on the nissan consult.

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[sky017]

try a boost leak test , or better yet if your in syd pm me and come past and ill have a look at it for you one evening . it could be a loose hose , or hose that is cracked to cause a hissing sound . i did a boost leak test a month ago and found at least 5 -6 leaks . soon as i attended to them all the car was so much more responsive

[Josh_TypeX]

I put my money on intake manifold gasket... Check around the intake manifold for a leak (between top & bottom halves and bottom & head)

[sadr33]

try a boost leak test , or better yet if your in syd pm me and come past and ill have a look at it for you one evening . it could be a loose hose , or hose that is cracked to cause a hissing sound . i did a boost leak test a month ago and found at least 5 -6 leaks . soon as i attended to them all the car was so much more responsive

Yea I am in syd. Sounds good I'll take you up on that offer. Maybe you can figure out why I cant outpace a Kio Rio till about 120kph even on 12psi

[OMGGTR]

I would say inspect turbo first make sure blades are ok nothing went through them chek shaft play etc then get ur hands on a stethoscope and keep snapping throttle to 4 or higher thousand rpm or when it whistles and using the stethoscope pin point the leak

[DVS JEZ]

Make sure the 4 bolts holding the turbo on havent come loose,

Check cooler pipe clamps

[Reflector]

A vacuum leak would be more of a hissing sound. They're also subject to causing surging, misfires or very noticable poor engine performance. Vacuum leak would also be on the inlet side. Is the sound coming from above the turbo when you listen under the bonnet?

Very similar situation happened to mine except I lost all boost - VERY loud 'supercharger like' whining. On inspection the compressor wheel on the turbo had shattered 3 blades. Perhaps yours has only done slight damage to a 1 blade? Also check for bearing wear in the turbo shaft, you'll hear a grumbling/growling sound when you free spin the shaft over if the bearing is worn. How many Kilometers are on the car AND is it the original turbo?

Sounds to me like the 10mins of unattended driving may have done the damage no one likes to hear.

Edited November 7, 2012 by Reflector

[kosmo90]

Isn't the timing meant to be at 20 degrees when idling?

[GTSBoy]

Depends on a couple of things. Which engine and which transmission being the most important.

[GoHard]

See if you can grab on to the intake pipe that joins to turbo and check its on tight. Because you were playing around over there before the problems started, thats what id be checking.

[sadr33]

Thanks for the repies guys. I think the whine is from the turbo the hiss not so sure. Ive decided to try a new turbo ill have a look for the hiss or get somonene to when doing turbo

I put my money on intake manifold gasket... Check around the intake manifold for a leak (between top & bottom halves and bottom & head)

Inatke manifold isnt in perfect condition but I dont hear the noise from there

I would say inspect turbo first make sure blades are ok nothing went through them chek shaft play etc then get ur hands on a stethoscope and keep snapping throttle to 4 or higher thousand rpm or when it whistles and using the stethoscope pin point the leak

If Im taking the turbo out with the help of a friend I better have a new turbo ready to go in. Not the mecanicall gifted enough to be able to pop stuff in and out on my own.

Make sure the 4 bolts holding the turbo on havent come loose,

Check cooler pipe clamps

They seem firm

A vacuum leak would be more of a hissing sound. They're also subject to causing surging, misfires or very noticable poor engine performance. Vacuum leak would also be on the inlet side. Is the sound coming from above the turbo when you listen under the bonnet?

Very similar situation happened to mine except I lost all boost - VERY loud 'supercharger like' whining. On inspection the compressor wheel on the turbo had shattered 3 blades. Perhaps yours has only done slight damage to a 1 blade? Also check for bearing wear in the turbo shaft, you'll hear a grumbling/growling sound when you free spin the shaft over if the bearing is worn. How many Kilometers are on the car AND is it the original turbo?

Sounds to me like the 10mins of unattended driving may have done the damage no one likes to hear.

Its possible, but car is boosting normally just new sound appeared. Oringial turbo 210km

Isn't the timing meant to be at 20 degrees when idling?

You talking about the nissan consiult video yea? Its all over the place isnt it...

Depends on a couple of things. Which engine and which transmission being the most important.

Engine is Rb25DEt on an ECR33 Auto

See if you can grab on to the intake pipe that joins to turbo and check its on tight. Because you were playing around over there before the problems started, thats what id be checking.

Nope its tight.

[sadr33]

Anway here is a video.Ther is a lot of wind noise hitting the microphone, but mainly during the second pard and its clearly distinguishable. Sounds like somoene is blowing into the mic vs the clear hiss at the beggining of the video

View My Video

Edited November 11, 2012 by sadr33

[GoHard]

You say its boosting normal... But cant beat a Kia Rio within the legal speed limit on 12 psi? Rito

[Akshunhiro]

The new Rio's are quick, man!

Seriously though, you have a boost leak and the turbo is being overworked trying to hold boost.