Crackling Noise Intermittent from Engine, Help!

[Javier B]

Hi Explorer friends,

My 95 XLT 6cyl suddenly started making an alarming crackling sound intermittently from the engine. The best way I can describe this sound is like crackling electricity or a plastic bag stuck in vacuum cleaner. And when I say intermittent, I mean it appears to be entirely random for a few seconds and stops. Any speed, any rpm, even coasting, forward or reverse, with or without bumps or turns, AC on or off. Disappears for a bit, then happens again. Sometimes louder, sometimes more faint. So far it does not seem to happen while in idling or reving in Park. Does not seem to correspond to any change in performance of the car. It began after we had the car sitting in an airport parking lot in 100 degree Texas heat for about a week. Had been running perfectly until then, but within a minute of driving out of the parking lot it started making this bizarre noise off and on. Couldn't figure it out, took it to my mechanic who didn't have a clue and told me to keep driving til something breaks, which doesn't sound particularly encouraging. The car runs fine, but something is clearly wrong. As an aside, it seems to be leaking a small amount of Power Steering fluid, in case this may be related?

I've read on various forums that it could be ball joints or other steering issues, but since the sound does not seem to be in any way related to bumps, turns or speed, that sounds unlikely?

Any ideas welcome. Thanks!

So, an update to the noise:
( I'm still trying to record the sound, but its so sporadic that every time I have my phone out the sound stops)

I mentioned that it makes this sound relatively often when going slowly in reverse. What that sounds like is something like a ratcheting "geiger-counter" sound. Just like going forward, it only lasts about 2 or 3 seconds and stops. But the quality of the sound is a bit different in reverse, and when it happens it's always immediately after I start moving in reverse. I've driven an extra block in reverse and nothing, but those first 3 seconds are closest I've gotten to being able to replicate the noise somewhat consistently. Does this help with ideas?

UPDATE: AUDIO FILE OF SOUND IN REVERSE ATTACHED.

Update# 3: It seems like it's in the transfer case. :-( pulling it out and maybe putting in a refurb. Weird that it was so intermittent. Will confirm this later if issue is solved.

 

[J_C]

Can you record this sound and attach here or youtube/etc link to it? How fast does the sound repeat?

Bad ball joints sound nothing like crackling, maybe your fan blades are cracked and it only happens when the fan clutch kicks in? I'd write loose exhaust shields but would describe that more like a rattle than a crackle.

 

[Turdle]

Is starter drive gear fully retracting?

When noise is present, try shifting to neutral while rolling, and rev engine a tad. Does the shift or rev effect level or pitch of sound?

 

[Javier B]

Can you record this sound and attach here or youtube/etc link to it? How fast does the sound repeat?

Bad ball joints sound nothing like crackling, maybe your fan blades are cracked and it only happens when the fan clutch kicks in? I'd write loose exhaust shields but would describe that more like a rattle than a crackle.

I'll try that and see. But 2 things: if the starter gear is not retracting, wouldnt the noise be continuous rather than on and off? And second, the noise is only a few seconds at a time, so it will be hard to tell if shifting into neutral worked or was just random.

the noise usually lasts about 3 seconds or so, stops, and then randomly happens again after a few seconds, or up to a couple of minutes later. sometimes it happens repeatedly very quickly, and sometimes it can be a minute of silence. Earlier today I got it to make the noise repeatedly when shifting into reverse and backing up slowly. It did it like five times in a row and I thought "AHA" but then it stopped. And hasn't done it again no matter how many times I repeated the experiment.

Just now I tried to record the noise, drove around the block several times and zilch, no noise. Earlier today it crackled and clittered a dozen times around the block. I'm at a total loss. I've got a 4 minute recording of a perfectly running engine :-/
If I get a recording, I'll post it later.

 

[Javier B]

Is starter drive gear fully retracting?

When noise is present, try shifting to neutral while rolling, and rev engine a tad. Does the shift or rev effect level or pitch of sound?

I'll try that and see. But 2 things: if the starter gear is not retracting, wouldnt the noise be continuous rather than on and off? And second, the noise is only a few seconds at a time, so it will be hard to tell if shifting into neutral worked or was just random.

the noise usually lasts about 3 seconds or so, stops, and then randomly happens again after a few seconds, or up to a couple of minutes later. sometimes it happens repeatedly very quickly, and sometimes it can be a minute of silence. Earlier today I got it to make the noise repeatedly when shifting into reverse and backing up slowly. It did it like five times in a row and I thought "AHA" but then it stopped. And hasn't done it again no matter how many times I repeated the experiment.

Subsequently, the noise stopped altogether, so giving up on the search today. I wish I had another symptom to help narrow whats going on.

 

[Javier B]

So, an update to the noise:
( I'm still trying to record the sound, but its so sporadic that every time I have my phone out the sound stops)

I mentioned that it makes this sound relatively often when going slowly in reverse. What that sounds like is something like a ratcheting "geiger-counter" sound. Just like going forward, it only lasts about 2 or 3 seconds and stops. But the quality of the sound is a bit different in reverse, and when it happens it's always immediately after I start moving in reverse. I've driven an extra block in reverse and nothing, but those first 3 seconds are closest I've gotten to being able to replicate the noise somewhat consistently. Does this help with ideas?

 

[Turdle]

U joints?
Rear parking brake parts?

Take a look at the rear driveshaft , a good under the truck look. See if you notice any evidence of the front driveshaft yoke assembly contacting the plastic cover of fuel tank.

 

[J_C]

Is it 4WD? Transfer case or front differential going out? You might check their fluids.

 

[Javier B]

Can you record this sound and attach here or youtube/etc link to it? How fast does the sound repeat?

Here is a sound file of what it sounds like in REVERSE. The reverse sound is way more severe and loud than going forward. This is recorded on my phone from the driver's seat. (I'm not sure the audio file will post, but if it doesnt I'll redo it.)

 

[J_C]

The file posted. My best guess is transfer case. If it did it equally in forward or also idling parked/engine-revved then I'd wonder more if it were an exhaust rattle. I could easily be wrong!

 

[Javier B]

The file posted. My best guess is transfer case. If it did it equally in forward or also idling parked/engine-revved then I'd wonder more if it were an exhaust rattle. I could easily be wrong!

Interesting. I *just* had the gasket for the transfer case replaced before this noise started. It's currently back in the transmission shop for them to look it over. would make sense if something got messed up while replacing that gasket. fingers crossed. I hate mysteries.

 

[J_C]

^ Like not putting fluid back in it?

 

[C420sailor]

I have the same thing. Not sure what it is yet. Only when backing up slowly. Thinking it may be my disintegrating parking brake shoes

 

[Javier B]

^ Like not putting fluid back in it?

Yeah, it seems like it's definitely the transfer case, so we're pulling it out. NOT the result I was hoping for.

 

[410Fortune]

Find out what fluid they put in it
It maybe their fault and they should install a good used t case for you

 

[Javier B]

Hi Explorer friends,

My 95 XLT 6cyl suddenly started making an alarming crackling sound intermittently from the engine. The best way I can describe this sound is like crackling electricity or a plastic bag stuck in vacuum cleaner. And when I say intermittent, I mean it appears to be entirely random for a few seconds and stops. Any speed, any rpm, even coasting, forward or reverse, with or without bumps or turns, AC on or off. Disappears for a bit, then happens again. Sometimes louder, sometimes more faint. So far it does not seem to happen while in idling or reving in Park. Does not seem to correspond to any change in performance of the car. It began after we had the car sitting in an airport parking lot in 100 degree Texas heat for about a week. Had been running perfectly until then, but within a minute of driving out of the parking lot it started making this bizarre noise off and on. Couldn't figure it out, took it to my mechanic who didn't have a clue and told me to keep driving til something breaks, which doesn't sound particularly encouraging. The car runs fine, but something is clearly wrong. As an aside, it seems to be leaking a small amount of Power Steering fluid, in case this may be related?

I've read on various forums that it could be ball joints or other steering issues, but since the sound does not seem to be in any way related to bumps, turns or speed, that sounds unlikely?

Any ideas welcome. Thanks!

So, an update to the noise:
( I'm still trying to record the sound, but its so sporadic that every time I have my phone out the sound stops)

I mentioned that it makes this sound relatively often when going slowly in reverse. What that sounds like is something like a ratcheting "geiger-counter" sound. Just like going forward, it only lasts about 2 or 3 seconds and stops. But the quality of the sound is a bit different in reverse, and when it happens it's always immediately after I start moving in reverse. I've driven an extra block in reverse and nothing, but those first 3 seconds are closest I've gotten to being able to replicate the noise somewhat consistently. Does this help with ideas?

UPDATE: AUDIO FILE OF SOUND IN REVERSE ATTACHED.

Update# 3: It seems like it's in the transfer case. :-( pulling it out and maybe putting in a refurb. Weird that it was so intermittent. Will confirm this later if issue is solved.

So I left this dangling here for over a year because this turned out to be a bizarre transmission problem. It was a rebuilt tranny still under warranty so the guys spent like two weeks trying to find what the problem was but it was fixed! It was NOT the transfer case after all. They replaced it and the problem remained. I don't know enough about the insides of trannys to know what was wrong. thankfully, it was under warranty.