cause of boost whistle in g60

[beckyg60]

Alright, so a while ago i remember on bahn brenner's website there was an explanation involving the noise coming from the throttle. Can't find it on their website.
Tried the search on here before the software switch, couldn't come up with anything.
Tried it after software switch with less success than before.

My old charger does it, my new charger doesn't. I'm just curious, does anyone know what the heck it is?

Sample video: listen for it at the end.

[G60ING]

Chargers will sometimes whistle when the apex strips are worn. I had a problem with my custom 85mm inlet charger and it would whistle. I capped off every possible place under the hood and made a pipe go straight from the charger to the TB only to still have the whistle. I opened up the charger and then saw the worn apex strips.

[beckyg60]

well that sucks... i like the whistle!

[G60ING]

When I deleted the boost return pipe on my car I would get a whistle as the boost return butterfly would open and close.

[crzygreek]

When I deleted the boost return pipe on my car I would get a whistle as the boost return butterfly would open and close.

x2 but i can definitely be a case of worn apex seals

[TheBurninator]

When I deleted the boost return pipe on my car I would get a whistle as the boost return butterfly would open and close.

I found that to be the most obnoxious noise EVER on a G60

[G60ING]

i agree and its makes it difficult to track down boost leaks

[RedYellowWhite]

Did you ever find what caused the whistling sound?

Mine is doing a similar continuous whistle sound lately, only when on throttle/boost...

Really sucks if it'd be worn apex strips

[petethepug]

Mine stopped after I had the 1.9 put in. The same G Ladder, vacuum lines and boost tubes were installed on the new motor. The only thing that occurred was the removal and install of everything on the motor

[crazynorweegian]

Mine stopped after I had the 1.9 put in. The same G Ladder, vacuum lines and boost tubes were installed on the new motor. The only thing that occurred was the removal and install of everything on the motor

Some of the euro forum sites said people had this problem after dumping the carbon can and associated lines. They figured it was like blowing on the edge of a bottle. The solution was adding a few feet of vac line to the lower throttle body vac line port by the boost return pipe and capping off the end of that line instead of just capping the port itself. I would say that, or the classic: throttle screw. Those are easy things before going straight to rebuilding the charger.

[sdezego]

Some of the euro forum sites said people had this problem after dumping the carbon can and associated lines. They figured it was like blowing on the edge of a bottle...

This is my personal experience.

[RedYellowWhite]

Some of the euro forum sites said people had this problem after dumping the carbon can and associated lines. They figured it was like blowing on the edge of a bottle. The solution was adding a few feet of vac line to the lower throttle body vac line port by the boost return pipe and capping off the end of that line instead of just capping the port itself. I would say that, or the classic: throttle screw. Those are easy things before going straight to rebuilding the charger.

This is my personal experience.

Thanks guys, I'll look into it , but the weird thing (that leads me to believe it may be worn apex strips) is the fact that I bought the engine with the carbon canister deleted and it didn't make that sound before - only now it has developed that whistling sound...

I must also mention that few days ago I did shortened the vac.line that was used to cap the TB port. to clean the engine bay a little - may that few cm less played their role...

[evosilica]

I have deleted the carbon canister and all the vacuum lines 3 years ago and it didn't change the sound at all. Never whistled. (btw. what is discussed in german forums is that whistle noise under no load, when shifting gears, not under full throttle. Some love it - like a blow off whistle, i think it sounds stupid.)

BUT, since a few months mine started to whistle on full throttle, too. My charger has been rebuilt ~4000km ago so i don't think it's my apex strips. But i haven't checked for any leaks yet.

[RedYellowWhite]

Ok, update: the idle screw is there and the vac.lines behind the TB are on and tight
Boost hoses, RSR outlet & all conections are tight as well...

Only thing I changed (besides the shortened vac.line that was used to cap the un-used TB port) was the serpentine belt but I doubt that would have anything to do with the whistling sound

[g60301]

Just deleted the carbon canister on mine and now it whistles when I push the clutch in (while driving ) I capped side of throttle body, One on the back of manifold (next to ecu vacuum line) the "T" on front of manifold, and one of the lines on check valve (clear vacuum line). Am I correct?

[G60ING]

Sometimes a whistle can come from the charger when the apex strips need replacement. It's very difficult to verify s you have to open up the charger to confirm. On my g60 way back in the day I removed all vacuum lines and capped the engine ports to pinpoint the charger. I don't recommend this because you will lose the brake booster and talk about stiff pedal with no brake performance. But I was dead on with my trouble shooting. My apex strips were shot.

[RedYellowWhite]

Frank, from the research I've done most say that if its worn apex strips then you can hear the whistling sound on idle near the g-lader/airbox area.

Mine is not noticable on idle, only on part throttle and WOT. Could this indicate that its in fact a vac and/or boost leak? I'd hate to open up the charger just to find out that its not the apex strips

[G60ING]

Mine didn't present at idle, at peak boost there was a slight whistle and 1.5psi of boost lost. I did a lot of trouble shooting vacuum lines before suspecting the charger.

[petethepug]

I know my strips are worn and slapping around in there. I running a 2nd hand charger right now. My whistle duplicated what Frank's saying ... at least until the new motor was swapped in.

The other little tidbit that's occurring on my charger (with worn apex strips) is that it gives a honk like a BOV after 5K when I'm romping on it. I can't duplicate it at stand still, only on load / car moving.

[RedYellowWhite]

Damn, I guess I could always remove the boost return pipe (glader side) and check if I can see any apex strips hanging in there - if not we'll see...

Thanks for the suggestions

[wed3k]

this was the cause of my whistling, im surprised that it still made 4 psi.

[sdezego]

Mine does it when coming into Vac at part throttle and was definitely created when removing the vac hose off the TB return that went to the canister.

A Whistle under boost would be leaning toward apex strips. Also, changing the Air box or charger outlet can certainly amplify noises. Especially if removing the air box for say the K&N, eurosport Cool flow or alike.

[RedYellowWhite]

Mine does it when coming into Vac at part throttle and was definitely created when removing the vac hose off the TB return that went to the canister.

A Whistle under boost would be leaning toward apex strips. Also, changing the Air box or charger outlet can certainly amplify noises. Especially if removing the air box for say the K&N, eurosport Cool flow or alike.

Oem airbox for me with just a K&N inside, has been like that for years (before the whistling sound)

Also, I did install a BBM RSR outlet a few months ago but it did not made that whistling sound at the time or afterwards so....basically I think I'm screwed and my g-lader sh!t the bed

[evosilica]

can you record it? i'm interested what it sounds like. i'm gonna record it in the next days too.

[RedYellowWhite]

can you record it? i'm interested what it sounds like. i'm gonna record it in the next days too.

I'm gonna give it a try...

[sdezego]

Oem airbox for me with just a K&N inside, has been like that for years (before the whistling sound)

Also, I did install a BBM RSR outlet a few months ago but it did not made that whistling sound at the time or afterwards so....basically I think I'm screwed and my g-lader sh!t the bed

I would rule everything else out first in your case - IMO. What is the history of your charger? I forget.

It is possible the you have a small boost leak somewhere. ..usually happens underneath a hose etc, in the most conspicuous and unsuspecting place LOL.

Have your boost levels changed at all?

[RedYellowWhite]

I would rule everything else out first in your case - IMO. What is the history of your charger? I forget.

It is possible the you have a small boost leak somewhere. ..usually happens underneath a hose etc, in the most conspicuous and unsuspecting place LOL.

Have your boost levels changed at all?

Shawn,

my charger was rebuilt before.
I can't tell how many miles before (my odometer is not working), can't be more that 4000 miles tho (I only drive my Corrado on weekends).

I doubt its a boost leak but I guess it doesn't hurt to check again...

My boost readings were always on the low side for a 68mm pulley (12-13psi), after this whistling sound occured (2 weeks ago) I didn't pushed it to see...

[sdezego]

Shawn,

my charger was rebuilt before.
I can't tell how many miles before (my odometer is not working), can't be more that 4000 miles tho (I only drive my Corrado on weekends).

I doubt its a boost leak but I guess it doesn't hurt to check again...

My boost readings were always on the low side for a 68mm pulley (12-13psi), after this whistling sound occured (2 weeks ago) I didn't pushed it to see...

I would not call that low, that's where mine has always been with the 68mm. Now, toward Redline, it will creep up more as the head stops flowing, but for the most part it is at 12psi.

Early chargers (1st) gen have a slightly smaller stroke that later gen chargers. There is also, the old talk about the larger crank pulley on autos and all later G60s. One thing is that I have always been dumbfounded by some claims about boost levels on a "68" pulley. Hell, maybe some of the companies "68 mm pulleys" were actually 67 or so LOL

Point being. you charger levels seem normal for a 1st gen charger on a 68. After a fresh rebuild with a lot of Kluber taking up space between the charger's leading walls can certainly produce increased boost levels for a brief period. $.02

It doesn;t hurt to pull off the outlet and look in there to make sure you don't see an apex strip slipping out etc. In my experience. 99% of the time high pitched whistles are not charger mechanicals but rather other items already discussed.

Did this just happen after shortening the hose cap on the Throttle body return? Because this the source my mine and (again) only did it after removing the CC, etc and capping off at the TB.

[RedYellowWhite]

Early chargers (1st) gen have a slightly smaller stroke that later gen chargers. There is also, the old talk about the larger crank pulley on autos and all later G60s. One thing is that I have always been dumbfounded by some claims about boost levels on a "68" pulley. Hell, maybe some of the companies "68 mm pulleys" were actually 67 or so LOL

Point being. you charger levels seem normal for a 1st gen charger on a 68. After a fresh rebuild with a lot of Kluber taking up space between the charger's leading walls can certainly produce increased boost levels for a brief period. $.02

^^Good info

It doesn;t hurt to pull off the outlet and look in there to make sure you don't see an apex strip slipping out etc. In my experience. 99% of the time high pitched whistles are not charger mechanicals but rather other items already discussed.

I plan on doing this asap

Did this just happen after shortening the hose cap on the Throttle body return? Because this the source my mine and (again) only did it after removing the CC, etc and capping off at the TB.

Yes, as a matter of fact it did



Maybe there is hope... I'll check some stuff over the weekend and report back

Thanks, really appreciate it

[crazynorweegian]

^^Good info



I plan on doing this asap




Yes, as a matter of fact it did



Maybe there is hope... I'll check some stuff over the weekend and report back

Thanks, really appreciate it

I don't have a link to share, but the euro forum I read about that vac port by the throttle body side of the boost return pipe suggested that a fairly long hose (vs a cap) would eliminate the whistle.

[RedYellowWhite]

I don't have a link to share, but the euro forum I read about that vac port by the throttle body side of the boost return pipe suggested that a fairly long hose (vs a cap) would eliminate the whistle.

Thanks

This would be the 1st thing I'll do on Saturday and report back

[evosilica]

i just saw, that my hose cap on the throttle body was missing. unfortunately putting a hose with the other end closed on it didn't really change much

i don't get how the hose cap on the bypass side can produce sounds under WOT. there isn't any air moving through it.

[evosilica]

so, this is what mine sounds like lately. as mentioned: charger has been fully rebuilt ~4000kms. i am driving a 68mm pulley.
you can barely hear it on the audio file, it's that whining sound on high rpm and high load.
the whistle noise when the throttle closes is normal.
i'm suspecting belt slip right now (the car also smelled like rubber a bit)

CC has been removed ~4000km ago, the noises started to appear ~1000kms ago.

i going to try the stock pulley, if it is beltslip, it should be gone, although i have a shorter belt for the 68mm pulley.

http://soundcloud.com/evosilica-demo...roubleshooting

[petethepug]

Just found this on my 2nd hand G60 I'm running in the car right now. BTW I'm running ISV bypass. I don't know if everyone who's having the "whistle" has their ISV stock or bypassed. This is the likely culprit of the honk / squeal I get after boost @ 5K.

I'm running a wide belt that's a little loose otherwise in perfect condition.

[RedYellowWhite]

so, this is what mine sounds like lately. as mentioned: charger has been fully rebuilt ~4000kms. i am driving a 68mm pulley.
you can barely hear it on the audio file, it's that whining sound on high rpm and high load.
the whistle noise when the throttle closes is normal.
i'm suspecting belt slip right now (the car also smelled like rubber a bit)

CC has been removed ~4000km ago, the noises started to appear ~1000kms ago.

i going to try the stock pulley, if it is beltslip, it should be gone, although i have a shorter belt for the 68mm pulley.

http://soundcloud.com/evosilica-demo...roubleshooting

Mine doesn't sound anything like that^^

Well, I guess tomorrow we'll know after I check some things...