The dreaded whistling noise

94 crimson SC

Registered User
I changed my head gaskets about a month and a half ago. The car runs awesome. Unfotunately about two weeks ago a whisling noise started coming from the engine whenever Iam at idle or not under boost. It is so loud you can hear it with the hood closed, 100 feet away. Iam assuming it is a vacuum leak somewhere. but I sprayed carb cleaner everywhere on the motor and I/C tubes and it makes no difference. I also diconnected the vacuum hoses one by one with no change. The car drives fine, idles well and is getting full boost. What could it be? Help please!!! Thanks!!!:(
 
Can you isolate where under the hood it is coming from? I would say maybe some sort of bearings. Water pump bearings can be pretty loud when they are on their way out.

Bob
 
If it is not the belts, could be the thottle body. On just a few cars I have heard thottle bodies wistle. If it happens to be coming from the tottle body it will be ressonating from th filter area for the butterfly. If it is coming from the thottle body, check your IAC, it could be the source. Try cleaning them with carb cleaner. Other than this, it is most likly a bearing going out, idler pulley, alt., water pump, and jackshaft, are all posible sources.
 
Sounds like a vaccum leak. Spray the carb cleaner all over, not just the IC tubes. Try spraying around the intake plenum, SC top, and intake manifold gaskets. The intake manifold gaskets will be the hardest to spray on, but thay deffinitly could have a leak. What is your vaccum gauge reading at idle? Should be somewhere between 18-20hg. If not this is a good indicator that you do have a vacumm leak.

Nick
 
The noise is definetely coming from the rear of the engine from behind the throttle body and supercharger, but I cant Isolate it. I have sprayed carb cleaner everywhere with no change. At Idle I have 19 inches of vacuum and no loss in boost under acceleration. If it weren't for the noise I wouldn't know I have a problem because the car runs fine. Its definetely not a bearing. I believe it is a small vacuum leak, I just cant isolate it.I dont understand why the problem would surface 2 1/2 weeks after I replaced the head gaskets. I put all new gaskets and seals in. I will keep you all posted. Thanks
 
Can you make the sound start and stop when you gun the motor in the driveway, moving into boost and out?

Can you hear the sound for any period of time after the ignition is shut off?

Our engines are noisey due to those plastic tensioner pulleys and other things. If you can hear it for a split second after stopping the engine, you might be able to isolate it better if you have someone help you buy starting and stopping the engine as you try to isolate the sound.
 
Yes, when you gun the gas in the driveway it goes away until idle when it returns again. When the car is shut off it still makes the sound for a bout 3-4 seconds. It gets quieter and then goes away, like vacuum being bleeded.
 
Try checking all the vaccum hoses around the intake plenum. Check them at the plenum and follow them to where they go to. These hoses like to dry rot after somany years. Also check the PVC hose in the passenger side valve cover.

Nick
 
GOT IT, HAD THE SAME PROBLEM. IT IS THE LINE THAT GOES FROM THE BACK OF THE ELBOW SHAPED INTAKE (BETWEEN THE THOTTLE BODY AND THE SUPER CHARGER) AND THE HOSE GOING THOUGH THE FIRE WALL ON THE PASSENGER SIDE. MINE DRY ROTTED OFF AND WISTLED LIKE MAD.
 
Well I checked everything, took the rear plenum off resealed everything and checked all vacuum hoses. The car still whistled. Man I was pissed. To top it off, while I was running it, one of the coolant hoses to the oil cooler decided to burst from old age. At that point I was livid so I sprayed the hose all inside the engine to see if I could pinpoint the noise. When I sprayed the side of the throttle body by the TPS, the noise stopped. Today it didnt make the noise when I started it. I think it must be the throttle body gasket or something to do with that spot. I think the gasket absorbed the water and expanded, thats why it stopped, for now. I will replace the gasket. Ive never had such a difficult problem. Usually a noise like that would be easy to find, but it was so loud that I couldnt tell where it originated. Thank you all for your help. I will let you know if it recurs.
 
regarding the squeeky noise you had a while back

hey buddy, i was reading through the threads and i have the EXACT same problem right now to the "T" right after having replaced the head gaskets. I didnt get it initially but after a few miles i got it all the same ways you did. So can you tell me exactly what it was you did to fix it. That would be awsome. Thanks man
 
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