North American Turbocoupe Organization



Loud turbo noises...
sicsiksix Offline
Member
#1
Wasnt really sure what to call this post, but when I'm driving in boost (above 5psi or so) I can hear the turbo spinning making a fairly loud whirring sound. Then after I let off the gas I can hear it spooling down fairly loudly as well ('phsssssssst' sound)...is this common? or should it be fairly quiet? It sounds a little loud to me, but this is my first TC so I'm still working out all the odd noises.

Is it possible for the boost control solenoid to make this noise? When I was inspecting things in that area (moving the IRCM and painting the stock airbox) I noticed the boost control solenoid housing was coming apart (the little tabs that hold the top where the vacuum line go in are broken on one side so the top is not sitting flush with the body of the unit...if that makes sense). Can anyone suggest a easy/safe method for testing the solenoid?

[This message has been edited by sicsiksix (edited 08-23-2005).]
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trashline Offline
Posting Freak
#2
could possibly be a boost leak. cheack all vacuum hoses and intercooler hoses as well. get a gillis BCV to repalce the BCS. unless your trying to keep it stock. not sure if the BCS is suposed to come aprt mine is the same way.

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1966 mustang
1988 tbird

Originally posted by: fordprefect

Mine sounds like twenty crickets on meth!
Brian

www.BCPCustom.com

06 Cobalt SS
66 mustang 289 C4 handfully modded

Stingers IC install and tbird photos
http://community.webshots.com/user/trashline
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sicsiksix Offline
Member
#3
Vacuum hoses are all new/tight, and I've removed/cleaned/inspected the intercooler hoses and they both check out perfect. Same with the VAM hose, cleaned out the oil, replaced the PCV and stuck a villager check valve in there as well. I did break a bolt off the turbine outlet elbow to turbine housing, but wouldnt that cause low boost/lag rather than noise?
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Ryan H Offline
Posting Freak
#4
Have you checked the blades for play/damage?

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Ryan Harris

88 TC, 5 speed, B&M Ripper Shifter, Walbro 190 LPH, Aeromotive FPR, K&N, 3.73's, 88K miles
'88 TC Smile Walbro 255HP, Stinger FMIC, PIT BOV, Pro 5.0, Kirban, RR cam, FRPP strut tower brace, T3
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Joe F Offline
Posting Freak
#5
Do you have the stock airbox or an aftermarket cone, like K&N? If it's an aftermarket setup, you will probably hear the air getting sucked into the turbo pretty good (at least I do) and a kind of "whoosh" when you let up on the gas after boosting. IOW what you're hearing may be perfectly normal. Aftermarket intakes and high flow filters don't muffle the intake near as much as the stock stuff does.

HTH.

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Joe F.
JR's Aerie - Our 3 TC's
JR's Place - My '87 Turbocoupe
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sicsiksix Offline
Member
#6
The blades have minimal play, few thousanths in/out and a few thousanths up/down/side/side. I'll check 'em again tonight if it stops raining with a dial indicator and see what I get.

As for air filter, its a stock setup with a new fram filter in it. No aftermarket goodies on there quite yet. Maybe I'll get a piece of garden hose in there and see if I can pinpoint any unsual sources of noise.
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Pete D Offline
Administrator
#7
The stock BCS' can come apart. As to whether they leak or not, they can.
Pete Dunham


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sicsiksix Offline
Member
#8
Hmm, well I guess I'll run a vac line directly from the 'T' on the IC to the WGA and see if the noise disappears...by removing the BCS from the picture (leaving the electrical connected as to avoid codes) I should technically get around 17 or so psi?
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Turbo Coupe Offline
Senior Member
#9
mine does that, sounds really cool. remember, vaccum leaks are boost leaks, if something was leaking youd be missing out on a whole lotta boost pressure.

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1987 Turbo Coupe 5 Speed - 14.528 @ 90.50
-93 Style Black Cobra Wheels w/ 255 45 17s
-2.25 Turn Cobra Rack
-Aeromotive Regulator
-Intercooler Fan
-6AL Box & Two Step
-Cone Mounted on VAM
-BCS Disconnected, 17-18 psi
-Weight Reduction
3318lb Race Weight
WISH I HAD MY OLD CAR AGAIN!
R.I.P
1987 Turbo Coupe 5 Speed - 1.77 60ft, 8.811 @ 76.76 1/8th
-Draglites With Hoosier QTPs & 165Rs
-Weight Reduction
29xxlb Race Weight w/Driver
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sicsiksix Offline
Member
#10
Well I guess I've missed a vac leak or my turbo is just worn. I bypassed the boost control solenoid and can only get about 14psi max. If this rain would let up it would make investigation alot easier.
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