Growling Noise at speed when let off gas

[Sevenpelicans]

Hi,

I was wondering if anyone can point me in the right direction to begin fixing this issue. The best way I can describe my issue is that when I get approx. above 50mph, while driving my 93 xlt, and I let off the gas to slow a little, the car rumbles or growls. I don't know why and it goes away once I get back on the gas and car starts to accelerate again. It also seems to catch up with itself some how as well. I will let off the gas on a downhill completely it will rumble at first and within a few seconds it will usually stop. It is usually when the car has more speed than the pedal is pushed. I don't know if that makes sense but, on a downhill or when your coming to an exit you naturally let off the gas and the car is still going pretty fast, particularly on a downhill, this is when it happens the most.

I realize I am not giving a great description so please feel free to ask any questions to further describe the problem.

Thanks for your time and any of your comments are appreciated.

 

[bluesman2333]

I'd check for broken belts in a tire or a bad U-Joint.

 

[pugsy]

I second driveshaft U-joints. Put in neutral and check for play.

 

[Sevenpelicans]

Its definetley not the tires there in great shape. Ill check the u-joints when I get a chance.

Any other suggestions? Has anyone else had this problem?

 

[bluesman2333]

I'd recheck the tires if the u-joints look good. Go to a tire shop for a free check if you have to. I've had bad tires that didn't look bad on first glance but the noise went away after the replacement. Check for slop or loose parts in the front end in general, especially the drive train components.

 

[manaen]

yeah my vote's on the u-joints

 

[xjames]

The u-joints and tires are good place to start. If no problem is found I would look into the rear end. First check the oil level in the pumpkin maybe even drain and fill. The oil will float on top of any water if it is present. Then check axles for excessive end play. Dry ring and pinions and wore bearings will cause that same reaction.

 

[Sevenpelicans]

Checked the U-joints they seem to be good. Same with the tires? Could it be anything else?

 

[bluesman2333]

Since the easy stuff is done, check things like differentials including ring and pinion fit/wear and bearings. Could be backlash in the gears. Replace the oil with synthetic after you open them up if everything looks OK to see if the noise changes. This might tip you off where the problem is. Don't forget, sometimes things look OK but you need to check with gages or dial indicators to really know. Go over the manual for ideas too.

 

[L4CX]

Did you turn your "jake brake" off? Kinda sounds like one of those things from a Semi I'd go with that these guys are saying. I'm pretty new at this, but could it be the Torque converter? The way you said it catches up eventually sound like maybe a lockup problem? I always jump to the worst situation. But Maybe? Somebody tell me I'm wrong, if I am. Thanks.


P.S. Explorers do not have Jake brakes....It was a joke. those are the loud noises you hear when semi's are slowing down. It's just the driver using the Engine to help slow down....I believe.

 

[manaen]

If you shift into nuetral when letting off the gas does the sound go away or continue?

Alternatly if you try this in 1st or 2nd (these gears have full engine braking) does the problem get worse.

If you turn off the OD does the problem still exist?

Have you checked you tranny fluid, is it full/burnt/good?

 

[pitbulldell]

My fly wheel was cracked around the bolts when my truck did the same thing, it rattled when you let off the gas

 

[IZwack]

pinion

 

[turbo2]

check the rear diff.

had this happen,noise was only on decel only,no vibration,the center pin that locks the axles in the housing had wollowed out the diff. housing holes,this pin is held in with the little5/16 head bolt.also had one that made a lot of backlash noise and it was the outermost clutch discs for thepossi unit,they were dowm to metal and left tons of freeplay in spiders and all kind of weird noises hope it helps
turbo

 

[turbo2]

sub note on diff

these conditions only happened when the truck was in [ floot ] not accel or deccel. got dangerous cause the pin almost shot out of the case ,got lucky turbo

 

[billz260]

is the sound more of a whine that changes in pitch w/ speed? If so, then I would guess your diff gears are starting to show some wear.

My '94 sport started doing this about 20K ago.

But if the sound is mechanical grinding, keep checking the other's suggestions.

 

[Dazed&Confused]

I know this is an old thread but I'm having the same problem. Growling noise when off gas and going downhill in my 2004 Ranger. If I shift into nuetral the noise stop almost instantly.

Any Ideas?

 

[Roadrunner777]

Same answers... check u-joints, then rear diff slop.