Whistling noise

I took my daugher's car (98 SC2 AT w/53,000 miles) into the muffler shop for replacement of the flex pipe and resonator exhaust system was sounding noisy). After leaving, the vehicle now exhibits an air hiss (like vacuum leak type noise) that increases with increased throttle (not necessarily speed related - just putting gas pedal farther down the floor) When the throttle is released the noise disappears at any rate of speed, and the same applies when shifting the tranny from 2nd to 3rd to OD and back again. I had the muffler shop re-check the installation and welds and they indicate all is well underneath. The sound eminates from the front end of the car but exact location is tough to determine, though its definitely under the hood somewhere. There is no loss of power or anything else, just the hissing noise as if there is air being forced somewhere it shouldn't be. There were no loose hoses or fittings. This has been a great car so far....absolutely no oil burning or reliability problems, other than replacing said flex pipe and resonator. Any ideas out there? Thanks in advance :)

Reply to
Larry
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I wonder if they bumped the intake and the hose from the throttle body to the air cleaner is loose or has come off. With the radio off and the car sitting in the driveway, when you turn the key off do you hear a big whooosh sound?

Reply to
Jonnie Santos

Did you check the other end? Intake leaks around anything that sucks air?

The first thing I would do is get my wife out there with a thick cotton rag and have her "plug" the tailpipe as best as possible once the car was running. That would temporarily build up pressure and reveal any exhaust leaks better... If you could do it on a lift, that would be even better...

Joe - V#8013 - '86 VN750 - joe @ yunx .com Ask me about "The Ride" on July 31, '04:

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I'm not a total idiot... I am after all, missing parts.

Reply to
Joe Dufu

I think you are hearing the air being sucked into the intake. Mine makes a quiet whistle when the gas pedal is in the floor. Maybe you couldn't hear it before because the exhaust was noisy.

Reply to
c0smic

There is absolutely no noise coming when turning off the key. I did pull the air filter out and the housing appears to be very tight. Sounds are tough to detect where they come from specifically, but it does sound like it comes from the passenger side of the engine compartment and the air filter is on the opposite side. And with the car parked and reving the motor up, the noise only comes briefly during the quick revving process of the engine.....its much more prevalent when the car is under load and actually moving, though the noise has no relation to vehicle speed or wheel motion. The noise is also very noticeable and isn't just a light whistle or hiss.

Reply to
Larry

If you said squealing I'd suspect a belt or tensioner.

This model year doesn't have an air pump does it? How about the PCV valve or line - they in good shape? There's another hose (vent line) from the valve cover to the intake. That's about all I can think of.

Reply to
Jonnie Santos

No...definitely not squealing...I had that last winter and replaced the sepantine belt which solved that. This is more the sound of air than the sound of mechanical lubrication.

Reply to
Larry

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