Odd air leaking noise
Thread Starter
|
New User
Joined: Mar 2009
Posts: 20
Likes: 0
Odd air leaking noise
If I weren't already bald this would cause me to pull all my hair out. I have an 02 EXCURSION V10 Limited 4x4 104k. I have what sounds like an air leaking noise only when the vehicle is moving, in 2wd, under load, approx 1700-2000 rpm. The noise is similar to a schu schu schu schu etc. and leaves when speed and rpms leave that range. This does not occur in park while revving and also cannot be heard while wheels are chalked and brake is applied, in D, rpms in range. The noise is not metallic and sounds like a loud vacuum leak but is not constant when driving and also has no felt effects on driving whatsoever. I have inspected the pcv and it seems to be operational but will be replaced. Recently it has been suggested that it may be a vacuum issue with the Temp. Accuator door. Any suggestions or insight would be greatly appreciated. I read the forum all the time but this is my first "cry for help." Thanks for reading
Cargo Master
Joined: Jul 2009
Posts: 2,885
Likes: 26
From: Chino, California
I'm thinking it's wind noise or maybe your tires out of balance? Sounds like at that rpm, there is a frequency which resonates just right. Maybe a heat shield? Can't tell without hearing it. Is it a fast schu schu schu?
Thread Starter
|
New User
Joined: Mar 2009
Posts: 20
Likes: 0
Tires are less than a yr old and i have had a recent alignment. The "schu-schu" noise is fast, like 3-4 per sec. Also, i've removed the heat shields from the y-pipe as the welds had broken almost free. Tire place did not mention the issue nor try to get more $ to investigate. Thx for reading and replying. Ever heard of the Temp accuator door?
Senior User
Joined: Apr 2006
Posts: 219
Likes: 0
From: vermont
Tires are less than a yr old and i have had a recent alignment. The "schu-schu" noise is fast, like 3-4 per sec. Also, i've removed the heat shields from the y-pipe as the welds had broken almost free. Tire place did not mention the issue nor try to get more $ to investigate. Thx for reading and replying. Ever heard of the Temp accuator door?
I wouldn't describe my sound like yours, was first thinking my roof racks were whistling; moved them to the back, didn't make an ounce of difference, and anyway they never made the noise before in their original position.
Started thinking I had a window not shutting completely but that was easily taken out of equation.
The one thing I can tell for sure is that it is consistent with the heater blower. Turn the fan on higher, the sound increases - so the blend door sounds like a good theory. It was actually my next spot to check before I saw your post.
My truck sat for quite a few weeks without driving, didn't have the noise before it sat. Seems like a vacuum noise the more I listen but doesn't change with rpm - so that makes me believe it down-stream, like heater controls. I'll let you know what I find unless you find yours first.
Thread Starter
|
New User
Joined: Mar 2009
Posts: 20
Likes: 0
My noise doesn't really present as a "wind" type noise. I have not messed with the different temp settings as it does it when the temp controls are off and the windows are down. According to a co-worker, there is a vacuum accuated door that regulates the air from outside, mixing with the cooler air from the AC, to set the thermostat temp when using AC. His theory is that some where on the assembly there is a vacuum leak or line off that is allowing that door to "flutter" air when a certain rpm is reached under load/travel due to increased vibration. Its the wife's rig so it'll be a day or so before i can tear into it further. thanks though
Senior User
Joined: Apr 2006
Posts: 219
Likes: 0
From: vermont
On the way in this morning; heater controls off, windows up - no noise until I hit about 30mph.
Switch to any position on the controls; noise changes slightly.
I'll be under the dash this weekend.
Switch to any position on the controls; noise changes slightly.
I'll be under the dash this weekend.
Trending Topics
Freshman User
Joined: Nov 2009
Posts: 45
Likes: 2
From: Southern Maine
Boy, this sounds very similiar to the dreaded exhaust "flutter" to me. You may want to search the forum for other members discriptions of their underside noises. You even used the "f"-word in your last post! Haha. It's also right in the rpm zone that mine was.
Hope this helps...
Hope this helps...
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
Laughing Gas
Joined: Jul 2010
Posts: 1,174
Likes: 2
From: Flat Rock, MI
If I weren't already bald this would cause me to pull all my hair out. I have an 02 EXCURSION V10 Limited 4x4 104k. I have what sounds like an air leaking noise only when the vehicle is moving, in 2wd, under load, approx 1700-2000 rpm. The noise is similar to a schu schu schu schu etc. and leaves when speed and rpms leave that range. This does not occur in park while revving and also cannot be heard while wheels are chalked and brake is applied, in D, rpms in range. The noise is not metallic and sounds like a loud vacuum leak but is not constant when driving and also has no felt effects on driving whatsoever. I have inspected the pcv and it seems to be operational but will be replaced. Recently it has been suggested that it may be a vacuum issue with the Temp. Accuator door. Any suggestions or insight would be greatly appreciated. I read the forum all the time but this is my first "cry for help." Thanks for reading
Senior User
Joined: Apr 2006
Posts: 219
Likes: 0
From: vermont
I couldn't find my noise under the dash. All heater positions seem to be working properly.
Going to get the boy to move around the cabin (on unpopulated roads of course) and see if he can pin point it.
Going to get the boy to move around the cabin (on unpopulated roads of course) and see if he can pin point it.
Thread Starter
|
New User
Joined: Mar 2009
Posts: 20
Likes: 0
Thanks
After the posts here i did some more research and took it to a trusted coworker that still works for Ford and he said it seemed to be similar to the flutter issues that i've read about. Since i have the necked down y pipe, i'm gonna start by replacing that 1st and let ya know. Probably be a few weeks. thx all
Posting Guru
Joined: Aug 2011
Posts: 2,019
Likes: 2
I have heard the similar noise on my 02' limited excursion. 150k miles on it. When i accelerate at times i hear an air leak. Seems to be coming from the front left of the truck it almost sounds like a compressor being drained when the air is let out. Cant pin point it and have been at quite a while. Ill keep looking though and let you guys know what i find.
Thread Starter
|
New User
Joined: Mar 2009
Posts: 20
Likes: 0
Air leaking noise
I found it in another forum page. Laying under the rig, in the middle, on the housing where the engine and transmission meet, there are 2 "shields" in the front on the bell housing. 1 is heavy steel bolted tightly, the other is almost like sheet metal and only has 2 bolts on both sides. When the RPMs reach the range of say 1700-2100, it vibrates the thinner metal one causing the "air leaking" noise I described. When I read the other post I thought no way it could be that easy. I wedged a small piece of rubber, temporarily, behind it, and could not get the rig to make the noise. I then simply removed the thin metal shield, put some rtv gasket on it, waiting til it glazed and reistalled. No noise for the last 6 months. I was careful not to completely seal the entire shield as there is a dimple that appeared to be made for moisture to drain???? Regardless, that fixed my leak and severe headaches.