EX Noise problems

[dhollowa]

Hi Everyone,

I'm experiencing some noise from underneath my EX upon decelerating after a hard acceleration. It happen at about any speed and only if I remove torque from the drivetrain. Meaning that if a decelerate by gradually reducing the throttle no noise, or if I coast from a constant speed no noise. It only seems to be if I accelerate hard then take my foot quickly off the gas pedal then I get this rubbing noise for about 2-3 seconds. It happens in 2WD, have not tried 4WD. I suspect the u-joints. But the truck only has 16K miles on it so I'm second guessing myself.

The other noise problem I have is that there seems to be a fan or something running inside the dash only when the engine is running. If I turn the engine off and have the key in run - no noise. I opened the hood and it does not seem to be coming from the engine compartment. I do have the EATC and I noticed a white hose that attaches to the lower trim panel (beneath and left of the radio). I'm not sure what this does but I guess it's sucking in cabin air for the automatic temperature control.

Any thoughts or help would be very much appreciated.

Doug
04 EX Limited 4WD 6.0L - stock

[dhollowa]

I just thought I'd give everyone an update. Well it's not really an update since I still have not determined where the noise is coming from.

To better describe the sound, it sounds like someone is scraping a knife or using a plane back and forth against the bell housing 3 times. The first scrape is pronounced and the third scrape is barely discernible. Or if anyone has machine shop experience it sounds like a shaper.

It's killing me because as long as I don't jump on/off the gas it makes no noise and runs beautifully. I also pulled my 8K# TT this weekend and didn't get any noise driving normally (e.g. not jumping on/off the throttle). My plan is to keep driving it until it either gets worse enough to clearly diagnose or it fails. With my luck it will likely fail when I'm travelling later this year with the camper in tow in some remote area, temps in the upper 90's and the truck packed with cranky kids.

As for the other noise inside the cabin, have not diagnosed that either, just getting used to it.

[william_04_x]

Originally Posted by dhollowa

My plan is to keep driving it until it either gets worse enough to clearly diagnose or it fails. With my luck it will likely fail when I'm travelling later this year with the camper in tow in some remote area, temps in the upper 90's and the truck packed with cranky kids.

As for the other noise inside the cabin, have not diagnosed that either, just getting used to it.

that's a pretty common plan with that kind of stuff...sounds like you know exactly how it will go down too...

i hope it doesn't turn out to be anything major...

you're right about the white hose(in cabin air temp sensor)...if you turn the EATC off(actually press the off button), does the fan noise stop? is the noise constant, or will it time out?

i just got done troubleshooting why my EATC wasn't directing air to the vents on call..it ended up being a loose vacuum hose in the manifold behind the "bag hook"..easy fix, once i found the problem..

WELCOME to the ORG!!!

[dhollowa]

Originally Posted by william_04_x

that's a pretty common plan with that kind of stuff...sounds like you know exactly how it will go down too...

i hope it doesn't turn out to be anything major...

you're right about the white hose(in cabin air temp sensor)...if you turn the EATC off(actually press the off button), does the fan noise stop? is the noise constant, or will it time out?

i just got done troubleshooting why my EATC wasn't directing air to the vents on call..it ended up being a loose vacuum hose in the manifold behind the "bag hook"..easy fix, once i found the problem..

WELCOME to the ORG!!!

Thanks for the reply. I tried turning off the EATC and it's still there. Funny thing it's only with the engine running and the pitch varies with engine RPM. Maybe it is coming from the engine compartment somewhere and I can't hear it because of the engine noise. I read somewhere that someone had a vacuum pump running all the time. Any idea where this is located?

[william_04_x]

it's pretty hard to hear the vacuum pump running with the engine on..regardless, the VP is on top of the passenger side fender well in the engine compartment..

[dhollowa]

Your right, it's most likely not the vacuum pump if it's over on the passenger side engine compartment. Thanks for the info. I guess I could do a fuse pull test and start cutting power for the different electroncs/motors in the cabin? I'll see where that takes me.