Specs: 2004 Excursion 6.0 4WD
Problem: Strange noise when under load, I think also when just under a load and going uphill. It happens when I try to accelerate. No noise any other times.

Sound: I heard a similar sound in my '94 Explorer once when the transfer case fluid was low but it only happened in 4WD. The only thing I can think of that kind of describes the sound is a brief sound like a swing from a light saber in Star Wars. It sounds like it's coming from underneath the truck.

Any suggestions on what I should check? I'm going to check the transfer case fluid tonight if it's not raining again. Transmission fluid level is good. We need to figure this out soon because my wife and I are going to use the Excursion to trailer my Explorer from mid-Missouri to Colorado and back in just a little over a week!

TIA!

 

I would post any engine concerns in the 6.0 forum going forward, but it sounds like you're having Turbo farts which is normal when letting off the gas. To me, it sounds lie gremilns beating the hell out of my engine.

 

This is Bryan's wife. This doesn't sound like an engine issue sounds like it is coming from underneath the front seats. As Bryan said, it happens under load, not when letting off the gas. It happened once when we had 8 people in the vehicle and were going up a long steep hill. Then again while towing an unloaded trailer, less than 2000 pounds, when stepping on the gas to accelerate quickly on the on ramp. To me it sounds like a "whump whump whump" and you can kind of feel it on the passenger floorboard. It only does it a few times, then quits. I towed the trailer around a little, and had no trouble as long as I eased into the acceleration. We will be towing in the mountains though, so really need to sort this out ASAP. Planning to check other things too like bushings and u-joints, just trying to get some other opinions on what this could be. Any suggestions greatly appreciated, thanks!

 

My ol man has a 2005 F150 w/ only 29k miles and his truck is making the EXACT noise that was described by the poster. No turbo on the 4.6L.
Just thought I would mention.

At first it would happen very slightly and of course as described....up hill under load. Now just driving it today after a rain storm and it seems to be much more evident? hot moist weather? no idea....
Just thought I would mention this is happening on a gasser as well.

 

Hmmm...

is it like a "shudder" and more prevalent when making a hard right while accelerating uphill ?

 

I've been telling my pops he's full of $h** until yesterday. Out of our 10 mile trip it probably did it a total of 1 to 2 miles of it on and off. I've never heard it so much. At first it sounded exactly like loose bearings...very similar to a metal on metal sound w/ a lack of grease and slight over gap...like the sound when you shake a salt shaker, just involve some metal.
Then as we got further on, it started to be more of a shudder I would say...almost enough to make you think it was the torque converter or something, but ZERO vibration.
So we tossed it in four wheel and never heard a peep from it on the same uphill run where we always would. The crazy thing is there is no change in braking, power, handling, no feedback in the gas pedal, steering wheel, 4x4 lever....NOTHING!
It sucks just sitting and waiting for something to break, but at the same time at something that's been taking the trash to the dump and hauling a single sled in the back since 2005 w/ 30k miles shouldn't be making any sound, be it as cool as a light sabre or not LOL

 

Check the catalytic converter. I've heard strange sounds from them with internal damage. Remove it to give it a look and a shake. It should not be loose at all and any damage should be pretty obvious when you look in the inlet.
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Need to clarify here:

1. only happens under load when you floor (or nearly floor) the accelerator pedal
2. sounds like a brief loud hum (light saber) and goes away if you let off the pedal
3. has usually happened when pointed uphill
4. no shudder or vibration

 

For me at least:
it's any level of accelleration just cruising at 30, 40, 50 and it just comes with the added load of a incline.
let off accellerator and it's gone. No shudder anywhere in the gas pedal, 4wheel lever, steering column/wheel...
So far...if it's in 4x4 it doesn't show up. I will conduct more testing this weekend. Gonna steal it and take it to work...i have a 40 mile commute so it should do a few times.

 

You got the same noise that I have. I think it is the lockup clutch in the torque converter going bad. It does it right after it shifts into 4th gear. It is worse going up hill or accelerating lightly. If you romp on it, the noise is much shorter but still there.

Mine goes 1st-2cnd-3rd-4th-buzz then smooth. It is worse when there is just a little load and almost no acceleration.

Perry

 

Perhaps you're on to something. Talking w/ my pops, it's the only thing he can think of as well that still has rotational motion that would make such a noise but not affect feeling at the wheels. Unfortunately I think you're nailing it.

 

Is your pop a transmission guy?

Perry

 

No....We've done some rebuilds on different mfgs and years, and some B&M kits but that's all. I'd say we're both overall great "handy" mechanics. Not afraid to work on anything but not ase lol.

 

I talked to a buddy of mine and he says there is a solenoid that actuates that clutch in the TC and he said it might be on the weak side causing the clutch to oscillate during engagement. I also thought it might be clutch chatter like you get with a manual trans but I have never heard chatter on a wet clutch before and I am assuming the TC has a wet disk clutch inside it. I would like to see the guts of one. It also sounds like a dry bushing sort of noise but since everything is bathed in oil I doubt that is the case. I like the weak solenoid idea because mine shifts better if you are punching it a little. If there is an overrunning clutch in there that is not locking properly that might cause it as well. The old automatics use to be hydraulic only. Do the new ones use solenoids to open valves or do they actuate clutches directly? I really want to figure out what is going on before something breaks and kills the transmission. I am going to change the fluid soon or at least what I can without flushing it. When I pull the pan I guess that will tell me if I have major problems or not. I believe there is an intake strainer and also an filter in the cooling line? If the strainer is like the ones in a C6 I would not call it a filter. Could low hydraulic pressure as a result of a clogged filter cause my problems? I have not found much in the way of technical info as to how everything works in these transmissions. It would be nice to have a factory manual on the trans.

Perry

 

Found something that might help but I am not 100% sure I understand how this test is going to determine anything.

99-3-5 - Noisy T/C*

Problem - Some 1999 F-series with the 4R100 transmission may exhibit a rattle/scraping noise in the converter housing area of the transmission case.

Action - To diagnose, place gear selector in park and using a break out box, ground pin 54 (TCC). This will fully apply the torque converter clutch. Cycle the torque converter clutch on and off a few times by applying and removing the ground to pin 54. If the rattle/scraping noise is not present when the converter clutch is applied (pin 54 grounded), replace torque converter.

Affected Vehicles - 1999 F-Series Super Duty, 7.3 DIT, 4R100 and 1998-1999 E-Series built after 1/5/98. Some 1999 F-series 250HD/350/450/550 Super Duty and 1998/1999 Econoline Series (built after 1/5/98) and equipped with 7.3l diesel

Parts - Updated Converter: XL3Z-7902-DARM

Are you supposed to do this while driving down the road or what?

Perry