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Tapping noise (is it my lifters?)


Aloha Joe

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Edit: I’ve got an intermittent tapping noise and was thinking maybe it’s the lifters. video below. I’ve seen plenty of info about replacing them, but how do I check them? I’m trying to diagnose engine noise. I also need to change my valve cover gasket so I want to check lifters while I’m in there.
Thanks

 
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CodaMan

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I guess you could start the engine with the valve cover off amd see if the lifters pump oil through the top of the push rod, but that might make one hell of a mess.

Why do you need to test your lifters? Do you suspect a bad one?
 
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Aloha Joe

Aloha Joe

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I’m trying to figure out this intermittent tapping noise. Exhaust has been re-torqued at least twice before the video. I also changed from 10-30 full syn. to 10-40 conventional but no help.
 
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Aloha Joe

Aloha Joe

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I’ve had the Jeep for about a year and about 5000 miles. I don’t remember the tapping when I bought it. It had MIL for 02 sensors so I changed them, changed plugs, and finally changed cats which fixed the problem. The noise started after so I figured it’s the exhaust, but I’ve re-torqued several times (including loosening at down pipes and muffler, and torquing from front to rear.) I usually think things are not a coincidence but I’ve had pure coincidence night me before, so I still think it’s possibly not the exhaust.

I have to change the valve cover gasket so just wondering what I can clean or check during that job.
 
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Meanjoegreen

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I had a similar ticking. Loudest on cold starts and quieted down a little once warm on mine. I added half a bottle of marvel mystery oil to the engine and the ticking was basically gone.
 

Rubicon John

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I watched your video - That noise is coming and going right? Loud and obnoxious one minute and quiet the next?

My 4.0 did the same exact thing, sounded identical. Mine has high mileage. I did a BG intake cleaning service and it went away and hasn’t come back.

My issue, in my opinion, was a carbon buildup on the exhaust valves. The valves can spin while the engine is running. So it would make the noise when the part of the valve with the carbon buildup spun into the right place and then the noise would go away as it continued to spin. Then come back, etc.

I would recommend a top end carbon cleaning treatment if this is the case on your engine. Mopar Combustion Chamber Cleaner works great ($17 a can on amazon) or you could even try the water method although I don’t know how well that would work for valves as opposed to piston tops.

The BG product is only available at shops and you can’t buy it over the counter AFAIK
 
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Aloha Joe

Aloha Joe

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Yeah, sometimes it’s silent at start and gradually gets louder, stops completely, and starts to come back. Sometimes it’s really loud right at start. Once in a while it’s just quiet. Sometimes it seems like it goes away when warm, other times I hear it faintly while driving.

it gets faster with rpm but not louder. It’s always the same frequency at idle. But it does sound like it’s coming from at least 2 distinct places (2 valves, 2 leaks, 2 whatever).)
 

Rubicon John

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Yeah, sometimes it’s silent at start and gradually gets louder, stops completely, and starts to come back. Sometimes it’s really loud right at start. Once in a while it’s just quiet. Sometimes it seems like it goes away when warm, other times I hear it faintly while driving.

it gets faster with rpm but not louder. It’s always the same frequency at idle. But it does sound like it’s coming from at least 2 distinct places (2 valves, 2 leaks, 2 whatever).)
Sounds like what I was dealing with. I’d recommend a top end cleaning before you dive into anything serious.
 
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dvTJ

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Yeah, sometimes it’s silent at start and gradually gets louder, stops completely, and starts to come back. Sometimes it’s really loud right at start. Once in a while it’s just quiet. Sometimes it seems like it goes away when warm, other times I hear it faintly while driving.

it gets faster with rpm but not louder. It’s always the same frequency at idle. But it does sound like it’s coming from at least 2 distinct places (2 valves, 2 leaks, 2 whatever).)
Did you ever figure this out? I recently bought an 02 and it does the exact same thing for the first 6-8 minutes. Starts and stops abruptly.
 
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Aloha Joe

Aloha Joe

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Over the past couple weeks I added MMO, drove a little, and did oil changes. I added MMO on the way home from work and it was quiet by the time I got home. So I did that twice. Last night I changed again with what I would consider “better” conventional 10w-30, Mopar filter and added a bottle of Rislone instead of MMO. It’s been very quiet. It still “makes noise” but it seems 95% better and I don’t expect it to be silent. Presently it doesn’t sound like “something is wrong.” At times the tapping was so bad I thought something was bound to break any second.

I’ll post back in a month or so for an update if I remember.
 

Flivver250

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You can use mechanic in a can cures for noisy lifters. They often work. MMO has been trusted for a century. Old lifters can chatter for a very long time without causing more grief than aural annoyance and TJ peer embarassment. When you eventually get tired of it, rebuild or replace. With the 4.0 you have to pull the head to replace the lifters. Depending upon the mileage, I'd be more inclined to rebuild the whole engine before I did half of it.
 

dvTJ

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You can use mechanic in a can cures for noisy lifters. They often work. MMO has been trusted for a century. Old lifters can chatter for a very long time without causing more grief than aural annoyance and TJ peer embarassment. When you eventually get tired of it, rebuild or replace. With the 4.0 you have to pull the head to replace the lifters. Depending upon the mileage, I'd be more inclined to rebuild the whole engine before I did half of it.
Thanks for the tip. What's odd is when it's ticking in the first 5-10 minutes of starting I honestly can't find it with the stethoscope. I'm gonna keep after it, but I've put that scope all over the valve cover and I can't hear lifters tapping. They all sound clean, and engine sounds good, but then I take the ear pieces out, and it's tapping somewhere close by. I've run it all a long the engine housing and honestly, I'm stumped.
 

Flivver250

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I have never been good at diagnosising noises from a video. The exhaust manifold itself or the gasket is often the culprit, but so are the lifters. The lifters are on the passenger side in the block. My original engine had about 90K miles on the clock and a couple of lifters were noisy until it warmed up, I too tried mechanic in a can. It helped. I was not too concerned, but then I found an entire drive train from a junkyard Jeep (imported for scrap from Japan) with almost no miles on it (I doubt it had ever been off road). I got a great deal on the engine, tranny and transfer and swapped it all out. Runs, shifts, and drives like new now.
 

hosejockey61

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I had a similar sound and it ended up being a bent push rod. One came out from under the rocker but the one next to it was the bent one. Replaced them both.