weird noise: throbbing whistle under boost
11-23-2013, 08:00 PM
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weird noise: throbbing whistle under boost
Usually I diagnose and fix whatever issues I have, but I cannot figure this one out. It started a while ago but this isn't a daily driver so I haven't made it a priority.
When it first started, it didn't always do it, then shortly after it did. Around the same time I started getting a boost cut which nearly always cuts in. I turned down the boost on the boost controller and it still went above the cut line. I also noticed the bolts on the hot side of the turbo are a little leaky causing a consistent smoking.
I thought it sounded like a vacuum leak, so I checked and replaced those. I checked all the intercooler piping, and I checked to make sure the wastegate was still tight.
Below are videos of the noise as well as the smoking turbo. Also, I thought you could upload Kals and datalogs?
backround/setup:
k20a3-stock
sc34 turbo (40k miles- never rebuilt)
tial wastegate
kpro tuned by Todd at Church
When it first started, it didn't always do it, then shortly after it did. Around the same time I started getting a boost cut which nearly always cuts in. I turned down the boost on the boost controller and it still went above the cut line. I also noticed the bolts on the hot side of the turbo are a little leaky causing a consistent smoking.
I thought it sounded like a vacuum leak, so I checked and replaced those. I checked all the intercooler piping, and I checked to make sure the wastegate was still tight.
Below are videos of the noise as well as the smoking turbo. Also, I thought you could upload Kals and datalogs?
backround/setup:
k20a3-stock
sc34 turbo (40k miles- never rebuilt)
tial wastegate
kpro tuned by Todd at Church
11-23-2013, 08:20 PM
#2
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Re: weird noise: throbbing whistle under boost
the turbine bolts being loose shouldn't make anything "leaky" either you've got a turbine seal on its way out or bad valve stem seals somewhere... or the worst case is its a horrible case or ring wear/blowby.
I can't play vids at the moment but is the smoke white (like a smoke screen, that would be coolant)... whitish blue (oil, again from bad blowby, valve stem seals, or a bad turbine seal) or black (carbon from running too rich)?
So 40k on the turbo... is this since it was new or did you buy it used and that's the mileage you've put on it? Where these miles lots of hard pulls/driving or mostly cruising/highway miles? Did you let the turbo cool down before shutting off the car (turbo timer or just waiting when you park for a bit)? What oil do you run (brand, viscosity, synthetic, semi-syn, what filter, etc)? What is your oil change interval? Have you checked the turbo for signs of shaft play since this started? Sometimes excessive play will kill seals (explains the bad seal and the smoke) as well as prevent the turbo from making consistent boost pressure.
When it makes the noise does boost fluctuate?
If it does, can you hear a sound change in the rpm/whistle of the turbo or does it sound more like a blow off valve leaking? What BOV is on the car? Does it have a proper boost/vacuum signal and is it adjusted properly?
Do you have a catchcan setup? If not that could explain some of the smoke
I know when I drive a fast boosted car something throbs but it isn't the car at all lol
Try to fill in the blanks of the questions I asked and that should give us some more data on the issue
I can't play vids at the moment but is the smoke white (like a smoke screen, that would be coolant)... whitish blue (oil, again from bad blowby, valve stem seals, or a bad turbine seal) or black (carbon from running too rich)?
So 40k on the turbo... is this since it was new or did you buy it used and that's the mileage you've put on it? Where these miles lots of hard pulls/driving or mostly cruising/highway miles? Did you let the turbo cool down before shutting off the car (turbo timer or just waiting when you park for a bit)? What oil do you run (brand, viscosity, synthetic, semi-syn, what filter, etc)? What is your oil change interval? Have you checked the turbo for signs of shaft play since this started? Sometimes excessive play will kill seals (explains the bad seal and the smoke) as well as prevent the turbo from making consistent boost pressure.
When it makes the noise does boost fluctuate?
If it does, can you hear a sound change in the rpm/whistle of the turbo or does it sound more like a blow off valve leaking? What BOV is on the car? Does it have a proper boost/vacuum signal and is it adjusted properly?
Do you have a catchcan setup? If not that could explain some of the smoke
I know when I drive a fast boosted car something throbs but it isn't the car at all lol
Try to fill in the blanks of the questions I asked and that should give us some more data on the issue
11-23-2013, 08:42 PM
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Re: weird noise: throbbing whistle under boost
the turbine bolts being loose shouldn't make anything "leaky" either you've got a turbine seal on its way out or bad valve stem seals somewhere... or the worst case is its a horrible case or ring wear/blowby.
I can't play vids at the moment but is the smoke white (like a smoke screen, that would be coolant)... whitish blue (oil, again from bad blowby, valve stem seals, or a bad turbine seal) or black (carbon from running too rich)?
Its not black smoke- Grey, or white I guess (maybe the whitish blue?)
So 40k on the turbo... is this since it was new or did you buy it used and that's the mileage you've put on it? Where these miles lots of hard pulls/driving or mostly cruising/highway miles? Did you let the turbo cool down before shutting off the car (turbo timer or just waiting when you park for a bit)? What oil do you run (brand, viscosity, synthetic, semi-syn, what filter, etc)? What is your oil change interval? Have you checked the turbo for signs of shaft play since this started? Sometimes excessive play will kill seals (explains the bad seal and the smoke) as well as prevent the turbo from making consistent boost pressure.
I bought it new, 40k total. Daily driving and beat on for first 35k, with plenty of track days. Except for beating on it and enjoying it, I ALWAYS take care of it. never get on it before its fully warmed up, always let it sit before shutting down. I have changed oil consistently every 2500-3000 miles using Mobil 1 syn. 5w-30 since turbo was added. Almost always a Honda filter, otherwise Mobil 1. I haven't checked play since this started happening, but there was some about 1k miles ago, but at the point it wasn't hitting the side so I didn't worry about it. And its not that its not making consistent power, the boost goes up but there isn't anything holding it where it should be, 12psi, and it keeps climbing until it hitting the boost cut.
When it makes the noise does boost fluctuate?
No, boost consistently grows until it hits the cut, nothing there holding it at 12 where it should be.
If it does, can you hear a sound change in the rpm/whistle of the turbo or does it sound more like a blow off valve leaking? What BOV is on the car? Does it have a proper boost/vacuum signal and is it adjusted properly?
BOV sounds fine and normal, greddy type-s
Do you have a catchcan setup? If not that could explain some of the smoke
NO
I know when I drive a fast boosted car something throbs but it isn't the car at all lol
Try to fill in the blanks of the questions I asked and that should give us some more data on the issue
I can't play vids at the moment but is the smoke white (like a smoke screen, that would be coolant)... whitish blue (oil, again from bad blowby, valve stem seals, or a bad turbine seal) or black (carbon from running too rich)?
Its not black smoke- Grey, or white I guess (maybe the whitish blue?)
So 40k on the turbo... is this since it was new or did you buy it used and that's the mileage you've put on it? Where these miles lots of hard pulls/driving or mostly cruising/highway miles? Did you let the turbo cool down before shutting off the car (turbo timer or just waiting when you park for a bit)? What oil do you run (brand, viscosity, synthetic, semi-syn, what filter, etc)? What is your oil change interval? Have you checked the turbo for signs of shaft play since this started? Sometimes excessive play will kill seals (explains the bad seal and the smoke) as well as prevent the turbo from making consistent boost pressure.
I bought it new, 40k total. Daily driving and beat on for first 35k, with plenty of track days. Except for beating on it and enjoying it, I ALWAYS take care of it. never get on it before its fully warmed up, always let it sit before shutting down. I have changed oil consistently every 2500-3000 miles using Mobil 1 syn. 5w-30 since turbo was added. Almost always a Honda filter, otherwise Mobil 1. I haven't checked play since this started happening, but there was some about 1k miles ago, but at the point it wasn't hitting the side so I didn't worry about it. And its not that its not making consistent power, the boost goes up but there isn't anything holding it where it should be, 12psi, and it keeps climbing until it hitting the boost cut.
When it makes the noise does boost fluctuate?
No, boost consistently grows until it hits the cut, nothing there holding it at 12 where it should be.
If it does, can you hear a sound change in the rpm/whistle of the turbo or does it sound more like a blow off valve leaking? What BOV is on the car? Does it have a proper boost/vacuum signal and is it adjusted properly?
BOV sounds fine and normal, greddy type-s
Do you have a catchcan setup? If not that could explain some of the smoke
NO
I know when I drive a fast boosted car something throbs but it isn't the car at all lol
Try to fill in the blanks of the questions I asked and that should give us some more data on the issue
11-23-2013, 09:42 PM
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Re: weird noise: throbbing whistle under boost
hmm, check the diaphragm in the wastegate, it could be kinked or torn, allowing a boost creep situation.
How are you controlling boost pressure? MBC, ecu controlled solenoid?
What brand wg are you using, size, spring,etc?
Check all of the pressure signal lines and fittings from the intake manifold to your boost controller/solenoid to the wastegate. If one of these is leaking or has developed a small hole then pressure could be bleeding off, causing boost pressure to creep until you hit the boost cut psi level preset in your ecu
How are you controlling boost pressure? MBC, ecu controlled solenoid?
What brand wg are you using, size, spring,etc?
Check all of the pressure signal lines and fittings from the intake manifold to your boost controller/solenoid to the wastegate. If one of these is leaking or has developed a small hole then pressure could be bleeding off, causing boost pressure to creep until you hit the boost cut psi level preset in your ecu
11-24-2013, 07:32 AM
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Re: weird noise: throbbing whistle under boost
hmm, check the diaphragm in the wastegate, it could be kinked or torn, allowing a boost creep situation.
How are you controlling boost pressure? MBC, ecu controlled solenoid?
What brand wg are you using, size, spring,etc?
Check all of the pressure signal lines and fittings from the intake manifold to your boost controller/solenoid to the wastegate. If one of these is leaking or has developed a small hole then pressure could be bleeding off, causing boost pressure to creep until you hit the boost cut psi level preset in your ecu
How are you controlling boost pressure? MBC, ecu controlled solenoid?
What brand wg are you using, size, spring,etc?
Check all of the pressure signal lines and fittings from the intake manifold to your boost controller/solenoid to the wastegate. If one of these is leaking or has developed a small hole then pressure could be bleeding off, causing boost pressure to creep until you hit the boost cut psi level preset in your ecu
Were you able to watch/listen to the videos yet? what does it sound like to you? vacuum leak?
11-24-2013, 09:38 AM
#6
Re: weird noise: throbbing whistle under boost
He has, and so have I. I'd check the internals of the wastegate itself. If the rest of the system is fine, start there. Sounds like there could be a leak either there, or... the Intercooler itself. check welds on the front and back as well. those make the largest leak sounds.
11-24-2013, 02:02 PM
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Re: weird noise: throbbing whistle under boost
yea look over the core closely, a rock could have punctured a tube.
an easy way to do this is put soapy water in a spray bottle and apply very liberally to the front of the intercooler, sometimes you'll see bubbles right away, if not have someone rev the car lightly for you while you look at the intercooler... the increased air flow/slight pressure increase from the turbo will cause any leak to start forming lots of bubbles, assuming you applied enough soapy water...
you'll need to keep spraying the intercooler as the water will run off quickly.
and yes, pull the wastegate off and check it.
Check the following
Fire ring/Valve condition (pitting, funny wear marks/worn places)
Check the valve for play in the housing, this could indicate the bushing between the wastegate halves has failed (if you pull the top off and check the bottom of the diaphragm, any signs of black soot will reinforce the failed bushing diagnosis)
Remove the wastegate top and inspect the diaphragm for tears, kinks, any damage... the smallest hole will cause major headaches
Inspect the spring for any signs of fatigue, small cracks, sagging... this means it's time for a new spring. Obviously if the spring comes out in pieces you already know you have a problem lol
an easy way to do this is put soapy water in a spray bottle and apply very liberally to the front of the intercooler, sometimes you'll see bubbles right away, if not have someone rev the car lightly for you while you look at the intercooler... the increased air flow/slight pressure increase from the turbo will cause any leak to start forming lots of bubbles, assuming you applied enough soapy water...
you'll need to keep spraying the intercooler as the water will run off quickly.
and yes, pull the wastegate off and check it.
Check the following
Fire ring/Valve condition (pitting, funny wear marks/worn places)
Check the valve for play in the housing, this could indicate the bushing between the wastegate halves has failed (if you pull the top off and check the bottom of the diaphragm, any signs of black soot will reinforce the failed bushing diagnosis)
Remove the wastegate top and inspect the diaphragm for tears, kinks, any damage... the smallest hole will cause major headaches
Inspect the spring for any signs of fatigue, small cracks, sagging... this means it's time for a new spring. Obviously if the spring comes out in pieces you already know you have a problem lol
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