High pitch whistle when warmed up.

HWNST185

New member
I couldn't find anything related to this by searching. I have this high pitch whistle when my engine is warm and pulling full vacuum. The sound is coming from around the throttle body or intake manifold. I have replaced a bunch of the vacuum lines in that area but it still does it. Last time I smoked the car there were no leaks. I have a FMIC and no cruise control if that helps any. Thanks in advance for any input, this is getting really annoying when driving around.
 
+1 on this condition. I have developed the same hi pitched whistle when warm coming from the intake manifold/TB area. this is during idle, once the rpm raises to above 1700rpm it goes away.

I haven't found the problem yet either.

anyone have an idea on this 3SGTE issue :(

I will add, other, than the annoying whistling, there doesn't seem to have any adverse performance or drive-ability effects.
 

MWP

New member
Yep, i get it also.
Seems to happen for a week or so, then go away for a few weeks.

A lot of my vac lines have been changed from the factory, and has a different idle air control valve, so you guys can rule those things out.
 
i was thinking of replacing the Idle air control valve because i'm starting to have a bit of an idling problem that hasn't gone away either. You're probably right, its not related to the whistling.
 

MWP

New member
To me it sounded more like the noise was coming from the head... so maybe a camshaft bearing.
Either way, im going to ignore it until it becomes bad enough that i can work out where it is coming from.
 

HWNST185

New member
Hmm, just changed the A/C idle up VSV and it did it before that too. My friend suggested it might be from the TB, so I think changing the last two hoses and cleaning the TB will be my next move. Thanks for the info on the A/C.
 
brand new AC idle up valve, but i'll fondle it just for good measure :twisted: Cleaned out throttle body and I have all new sili hoses. (not so say new means no trouble) I guess its just a process of elimination with these annoying things. My bet is a small vaccuum leak somewhere.
 

HWNST185

New member
I cleaned the TB and resealed the intercooler pipe fitting on the TB and so far so good after driving around the neighborhood for a while.
 

Corey

Active member
I drove my car yesterday. And found that the whistle stops once the car is warmed up, or when the engine RPM is higher than idle.

I've had my TB off in the past and have cleaned it out with compressed air. I also have new silicone hoses everywhere. Maybe the TB metal gasket needs to be replaced?
 

Darkstar20999

New member
:roll: i have to join this club to lol dnt know what it is but i have the same high pitch whistle sound its weird took it to a few ppl and seems the older guys cant hear it but alot of my friends that are younger can hear it just as easy as me lol so what is it lol
 

imperfect2099

New member
i had this same issue. i had a MBC and i removed it because i had no need for it and the whistle went away. it wasnt the intended outcome, but i was glad it fixed the problem anyways. good luck resolving ur issue.
 

underscore

Well-known member
I've got this too (only when fully warmed up), and I'm told I have a small vacuum leak around that piece that bolts to the TB and goes to the intercooler. I'm guessing once the rubber/metal heats up, expansion reveals the leak, and it's such a shape that it whistles?
 

bajachris88

New member
This reply is for the purpose of archiving my findings for future reference; it may help others.
(I found this thread via google when i was having the same issue, however it didn't have any findings of resolution for me to follow; so want to share mine for future GT4-ers).

I had high pitch whistle, originally was only when warmed up, then sometimes at 'any time' after 6 months later, however always more prominent when warmed up. Noise seemed to come from under the throttle body.

My MOTEC dash allowed me to monitor intake manifold pressure full time. The difference between manifold pressure when the Idle Speed Controller was open and closed must have been enough of a difference to trigger the noise and was from memory approx 2.5 to 3 psi vacuum.

So... I pulled apart the throttle body, reassembled, cleaned out ISC, put back together, no luck. However, did clean out a bit of carbon.

Used top end engine cleaner to address any further gunk. again, no luck in fixing the noise.

I then said... THATS BLOODY IT! Bought a VRS set off ebay and injector seals kit from a local supplier. I then set forth... (might as well have done a full head job with the amount of work).

On disassembly of the TVIS, I removed the TVIS butterflies and shafts. Only when I removed the shafts, I noted that there was a 'chip' out of one of the two little round 'oil seal style' seals that seals the two separate butterfly shafts as it passes through the intake runners. The position of these seals are central under the throttle body and out of sight for a clear 'spray of aerosol' trial for looking for vacuum leaks. I believe THIS ladies and gentlemen is the cause of our high pitch pain. The revs don't go up, as the vacuum leak is only on ONE of the four intake runners and small (or two if unlucky to have both bad) and too far down the manifold to rev up the other 3 cylinders as it is really at the cylinder head.

Fix: replace the seal after disassembly of the TVIS. unfortunately my TVIS was incomplete and not operational due to aftermarket computer. So i gutted it, and used epoxy metal putty (like JB Weld) to plug up these seal seats. Now all good.

Note: I did the intake manifold gaskets, and replaced the fuel injector O-rings which had their isolators 'pinched' by the numpties that fitted it, however I couldn't find any reason for those to make a 'high pitch' non-rev changing seal that wasn't sensative to spraying aerosol. I'm very confident it was the TVIS butterfly shaft seal.

I hope that helps guys... Basically means a big job but roll up the sleeves and expect alot of cuts on your hands. Removing the tie rod from the wheel hub, as well as the under engine cross member will give you alot of access without a hoist. You may be required to sit in the engine bay with your arm deep under / over (like I did).

I hope that helps somebody.

Thanks,
Chris.
 
Top