Metallic sound at 2000 RPM that goes away when switched to 4wd

[alcgraham]

Hi All, I have a 2004 Eddie Bauer edition with the 5.4 liter engine. I have 170,000 miles on it. On Monday when driving down the freeway my car started making a rattling metallic sound when I accelerated and the car went over 2000 rpm, it was louder when going around 55-60 but would stop when done accelerating. It also make a clunking catching type noise at that speed. Otherwise it is driving just fine. I decided to try switching it to 4wd to see if that made a difference and low and behold the noise is gone. I haven't driven it at highway speed again to see if it makes the clunk noise again but I suspect it will not. I am wondering if this could be a problem with the IWE system. I would love any input and direction so we can get this sorted out and fixed. Thank you!!!!

 

[johnboneske]

I've had that EXACT same noise, check the airline that goes to both front hubs, that's what kicks in the hubs when you switch to A4wd. Mine comes off occasionally in the passenger side.

 

[alcgraham]

Thanks so much for the tip. My husband has just gotten back into town so I will have him check when he has a chance and hopefully that will be our fix!!! It is crazy as it is driving totally fine in A4WD. Like those kind of fixes though Mine sounds like the front driver side.

 

[johnboneske]

Thanks so much for the tip. My husband has just gotten back into town so I will have him check when he has a chance and hopefully that will be our fix!!! It is crazy as it is driving totally fine in A4WD. Like those kind of fixes though Mine sounds like the front driver side.

Mine sounds the same way. It sounds like the front drivers side. Like a chain rattling and catching/hitting every so often, and when you let off the gas it goes away, until you get on the gas again. If you ever heard a loose timing, that's what it sounds similar too, but its the airline. It's located on the bottom of the spindle, inside near where the hub is, he will see a nipple sticking out without anything connected. That's where the air hose goes. Mine pops off about every 6 months

 

[alcgraham]

Great thanks so much!!

 

[alcgraham]

My husband is going to work on the car on Saturday and we are wondering if the vacuum line that goes to the hub is just a standard vacuum line or a special part. I have been looking but I can't tell. I just want to make sure we have a replacement in case it is torn. Thanks in advance for clarification!

 

[johnboneske]

My husband is going to work on the car on Saturday and we are wondering if the vacuum line that goes to the hub is just a standard vacuum line or a special part. I have been looking but I can't tell. I just want to make sure we have a replacement in case it is torn. Thanks in advance for clarification!

I haven't ever looked for a replacement, its easy enough to slide back on. There isn't a clamp or anything to hold it in place. I have never heard of one tearing it having a hole in it either.

 

[johnboneske]

a very small hose, and he will notice that there is two "stubs" sticking out of the hub where the hose goes. One is about 1/8" at best and the other just a hair bigger, he will see how it slides on once looking at it. I guess it could be glued on, but would be afraid of getting glue in the opening and then not letting the vacuum work properly.

 

[alcgraham]

Ok so an update. My husband finally got a chance to look at the car. There was a vacuum line at the front driver wheel that was a little loose so he fixed it. That made it much better but the sound was still there a little bit so we changed out the solenoid. Now it is only making a slight rattling sound occasionally, but not the clunking noise in 2wd. So we are wondering do we need to get a vacuum tester and test the vacuum system? Or any other suggestions.
Thanks!

 

[johnboneske]

I am sorry, I don't know about testing the vacuum? I never had to do that? I wonder if a smoke machine would work?

This is the one I have... Works great for finding leaks.

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/221913989725