“POP” on first take-off

[Atrus]

I’m not sure that I’ll be able to describe this well, but I am going to give it a try. Hopefully someone has experienced this.

I notice a “POP” when I first take off in the KJ, typically in the morning. Seems to be coming from the front, and probably 75% of the time it seems to be in the middle of the front suspension or towards the passenger side. Sometimes it sounds to be from the driver side.

It’s not a “CLUNK” like metal shifting on metal or anything. It’s kind of a medium tone (not high pitched or low pitched) and is just a quick “POP”…for some reason it really reminds me of something suspension related, like a spring or strut making noise. I know that makes no sense as our front shocks/springs are static and don’t pivot. I almost thought it was brakes – like a pad sticking to the rotor, but I’ve since changed all of the pads (due to wear, not the noise) and it still does it.

I believe it's done this when the wheel is straight as I am taking off, but it definitely does it religiously when I am turning slightly when I first take off. Also doesn't seem to matter if I am in 2wd or 4wd. It seems to do this only when I first take off after it’s sat for a while. I’ll hear it and try to replicate and it it will not make the noise again. It is almost everytime I take off in the morning (like 99.9% consistent) or when leaving work. I don’t get any unusual noises when driving, no banging or clunking in the suspension at all. I park in a deck on the weekdays and go over no less than 6 speed bumps at low and moderate (5mph to 15 mph) and don’t hear anything out of the ordinary.

Any ideas? I plan to check the LBJ’s tonight when I get home.

 

[Atrus]

Hmmmm, thanks Budke - I'll check that out.

I actually had the front DS out in October to make sure it wasn't the source of my noise/vibration issue (it was the front hubs), and it seemed OK. I'll check it again and make sure everything is snugged up nicely since I was in there playing around.

Heck, maybe I'll remove it for a week and see if the noise is still present.

 

[Atrus]

Could be, but it's just wierd that it's only on take off after sitting a while. I mean, I've had the rear driveshaft clunk before, this is different.

Back in Oct, I checked out the FDS rear boot - it was fresh in my mind because it seemed like we had 3-4 members (including you) posting about them being bad at that time. It looked perfect then, no drying or cracking noted.

 

[kj924]

It sounds like the brakes are frozen, and when you take off it gives a little "Pop" noise....mine does this when it's above freezing during the day and drops below freezing that night..then the next morning it makes the sound.

 

[kj924]

Mine don't do that when we get temps like that here.

Yeah, but you don't have a foot or two of snow/slush to drive thru either.

 

[Atrus]

Mine don't do that when we get temps like that here.

You don't get the same kind of temps, trust me.

Not that I have anything to ***** about when I see the doods from northern Canada posting.

 

[kj924]

You don't get the same kind of temps, trust me.

Not that I have anything to ***** about when I see the doods from northern Canada posting.

Where I live, we get a week or two of -30*C (-22*F) windchill, which we just went thru....Brrrrrrr!!!! That will make anything POP first thing in the morning....hahha.

 

[Atrus]

True. But lately we've been having lows in the high 20'sF and highs in the low 50'sF
And its just starting to come out of the lowest temps when I'm leaving work.

We've been having high's in the mid-to-upper 20's....for a while there we had high's in the low-to-mid teens.

This winter has actually been really mild on us. Two snowfalls, one of which I would only consider barely significant.

 

[yellocoyote]

Most of the 'popping' from my kj (in any weather) has been loose swaybar links, or bad cv joints. It's been pretty chilly here, and the jeep has been relatively quiet since I replaced the cv's. Not saying that's the issue for you, but something to look into.

 

[twack]

to the original poster, is this noise that you hear a coil noise? when your at a stop and you hit the gas to go there is one pop kinda noise as if something rubbed really ******* the coil? Like your not sure whats creating it but you can tell the coil is making the noise? does that sound like whats going on with you?

 

[Atrus]

Twack - It just sounds that way to me. It doesn't do it on hard take-off though, only the first time it moves after sitting for a period of time.

Jayme - good point, I'll check the endlinks as well.

I'm hoping to get out work at a decent time today and head out to the garage for an hour to investigate and change the oil.

 

[kj924]

I still say it's frozen brake pads on the rotors. Does it make the same sound in the heat of summer?

 

[Atrus]

I still say it's frozen brake pads on the rotors. Does it make the same sound in the heat of summer?

It didn't start doing this until it got cold out. Didn't do this last winter. Could very well be something with the brakes.

Started in November
replaced original pads (44k) in January
still makes noise with new pads.

 

[loves_off_roading]

I've been hearing a "pop" noise as well. But I hear mine after I shut off the engine

 

[Midgear]

Atrus-

with a second person, have one wiggle the steering wheel back and forth while you look at the rack and pinion and look for movement of any kind- mine pops and clunks because my bushings are worn-

just a suggestion!

 

[Atrus]

Thanks guys -

I am fairly limited on time at the moment. I did a quick once over and everything looks good. I am thinking it is some type of spring noise (not sure how), end links, or most likely of the three, brakes.

I just checked both LBJ's and I see no play.

So, it passes the "safety test" for now and I'll investigate in a couple of weeks when I free up. I feel better than I am fairly confident the wheel won't fall off on my way to work

 

[Simpleman]

Also check the rear upper control arm bushings and ball joint. Mine would pop like that, and it sounded as if it were coming from under the passenger seat. It almost sounded like the passenger seat was not fully locked position and would pop into place when I take off. It would only do it once. It was my rear upper control arm bushing.

 

[Atrus]

Thanks Simpleman - that actually makes a lot of sense from what I am hearing. I can completely see that the noise could be coming from there. I'll definitely check that out! Didn't even think of that until you mentioned it.