Rep Power: 142

Ever since I swapped on my Y8 manifold I had this whistling noise start. It is tremendously irritating, it it so freakin loud, sounds like a tea kettle when it boils. Only happens in colder temps when the car has sat for example overnight. After driving and stopping then starting again it won't do it. The belts are new, the alternator is new, the PS pump pulley is good, timing belt set is all new, all the hoses and vacuum port caps are new and in good condition, the manifold gasket is new etc. etc. The noise lasts between 20 seconds to sometimes 1 minute then goes away. Also sometimes it will whistle then will change to a even higher pitch. It will also stop if I press the gas pedal. I tried holding a hose to my ear as a make shift stethoscope and can't pin point it at all, although it does sound like it is coming primarily from the intake/passenger side. Refer to video to hear it.

 
Rep Power: 209

intake air leak,

did you clean the intake surface spotless before installing the new gasket?

torque bolts to spec?

 
Rep Power: 142

Yea did everything

 
Rep Power: 209

well me thinks you missed something

 
Rep Power: 142

Lol, exactly I just cant figure out what!

 
Rep Power: 518

Manifold vacuum leak...... Sounds like a reed whistle to me....What could act like a reed? One of the gaskets probably...... ?


Did you check for how well the manifold lines up to the head, and does the gasket fully cover all areas? Any real thin areas of overlap that might leave the gasket unsupported?



Poor seals between injector and manifold?

Use the hose stuck in your ear, go around the areas listening..... Underneath the manifold too. If you get to an actual vacuum leak, it should try to suck your eardrum out LOL

Use needlenose pliers to pinch off rubber vac hoses one at a time, listen for changes?





Get it squealing and remove the oil cap. Any change?

Smoke machine leak test?



The rubber hose you used for the EGR will probably disintegrate pretty quick while the EGR is operating. Exhaust is HOT and should char the hose.

 
Rep Power: 142

Alright Ill try some of those things out. As far as the hose for egr ive never seen anyone else do it any other way. What would you recommend instead?

 
Rep Power: 518

I've never seen rubber hose used in a high heat environment like that and have it survive any significant length of time, that's all.
I don't know if it will or won't in that application, I'm just sayin.

Manufacturers use metal to carry EGR gases.

 
Rep Power: 142

Did a smoke test, no leaks at all. Other tests to do with the engine running are getting hard to do. The sound only lasts for like 5 seconds now and goes away.

 
Rep Power: 142

so Ezone you were exactly right, pictured below my dumbass forgot to cut a spot out on the TB gasket for the new IACV port and it probably had maybe 1-2mm of space to pull idle air from causing the reed whistle effect as you had mentioned. Took the whole manifold off and am gonna clean it up some more and add a new properly cut gasket. Also the lines for the EGR still look great so hopefully they keep holding up.