The dreaded "tap"

CMTJ

CMTJ

TJ Enthusiast
Joined
Mar 31, 2017
Messages
248
Location
Jacksonville, FL, United States
Ok, it started about a week ago. Driving at normal speeds and I hear a tap sound. Kind of loud because my kids heard me coming home about 200 yards away. Metal on metal not continuous but very often even at slow speeds (10-15 mph) but also at higher speeds. I've been under the vehicle every day and checked every single thing I could. Any thing that had a bolt,clamp, ziptie, I mean EVERYTHING. Heat shields you name it. Now this morning I am starting to lean towards a bearing in the engine. Oil change the other day did not reveal any shavings at all. It was making the noise before the oil change also. Any thoughts to this?? Oil pressure is fine, no leaks. Thanks
 
CMTJ said:
UPDATE........... seems like it only does it when jeep is moving. Started it up and ran it in driveway and revved it a few times and no tapping.
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Cracked flex plate maybe? Happened to mine, it just wasn't as loud at idle. The tapping would be coming from underneath the Jeep, but with the hood open, it would sound like it was coming from the engine.
 
UPDATE #3 Ok took inspection cover off tranny and checked flex plate bolts. All tight. Still stumped. Now I did install a Zone 1.75 spacer and shock kit a few weeks ago. Had alignment done and good to go. Running 31's on stock rims. Other than that the Jeep is bone stock.
 
This is a long shot, but could it be one of your brake calipers tapping? I know that sometimes the part they rest on can get worn down a bit and cause them to move about and tap together at times. Does the tapping go away if you hit the brakes?
Just a thought.
 
Its not consistent enough but I checked all calipers for tightness and checked the heat shields around the upper resonators by the manifold and checked all brackets that hold the fuel and tranny lines.
 
As mentioned above I think your front brake pads are moving with the rotor a bit and clanging against the caliper. I have a k30 crew cab that has done that, very annoying. Ride your brakes and see if it goes away.

B
 
We need a few more details. Does it happen at all when the vehicle is stationary? Idle or reving? If it only happens when moving, does it change tempo or pitch the faster you go? Drive or neutral gear? Turning, straight, accel or decel, a/c on or off, hitting the brakes, etc. Try to make notes of everything that's happening when the noise occurs.
 
Does not happen when stationary. Does go a little faster when I accelerate. Only when moving. Like I said it in not a constant sound. Happens then stops, happens then stops etc. Did notice that when I am slower than 15 mph I dont hear it. When I give it gas I will hear it then it stops then starts again when I give it some more gas. Should I drop the rear dif cover and check the teeth??
 
Alrighty then!!!!!!!!!!!!!!!!! Front sway bar links were the culprits. Now I did mutilate the boots about 3 weeks ago when I put the lift on but didn't think much of it. I even grabbed and shook the hell out of them with no movement but I was gonna change them because i MESSED UP THE BOOTS and as soon as I drove off there was no banging. Eh, lesson learned.
 
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Awesome you found the noise and it wasn't serious! Pretty common for those to wear out quickly, mine went at around 50K miles. I never heard anything but suddenly developed a random clunk in the front when hitting bumps and found the broken link ends hitting the sway bar.
 
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Ok back to square 1. I was wrong in my diagnosis. I still have the tap. Not at idle, not when I rev the engine, only when I am driving. Seems to get a little faster when I give it more gas but then stops then sometimes starts up again. It is a metal tapping sound and its kind of loud when it happens. To recap, put in and out of 4w several times to see if that helped. No luck. Heat shield welds are good, ALL exhaust clamps tight, all suspension parts tight, brake calipers tight, ball joints tight, no noticable cracks in exhaust manifold, body mounts good, steering box good, all transfer case and trans linkage tight. Now a part of me wants to lean towards a bad main bearing and if I tear the oil pan out to inspect, might as well replace RMS while I'm down there. Any more thoughts???
 
If it was a main bearing or something internal in the engine wouldn't if make the noise all the time? If it only makes that noise while driving it, I would think it's some kind of rotational interference in the drive train. Have you opened up the diff cover to inspect the gears?
 
Yea I guess its smarter to check the easier stuff first. But maybe at idle there is not enough pressure or force to make the bearing move but there is when I give it gas. I don't know. I also did check the flywheel bolts and they are tight.
 
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