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cap10 crunch 02-28-2009 07:50 PM

Clicking noise help
Hello. I'm new to this forum and also a new driver :D Well i got myself a 1990 4.2 L YJ with 133000 miles on it and ive started to hear a clicking noise. It's constant and as i rev it gets faster and when its idled it becomes slower. It's really weird because if im stopped and its in neutral i can sometimes rev it and the noise just stops. That also happens if i get up to 2500 or 3000 rpms or it just goes away. The noise is like a metal fan slightly hitting something. It's basically as loud as my engine.

YjMopower 02-28-2009 08:02 PM

it could be your wheel bearings or maybe your fan is hitting the housing it happened to me once.

amerijeep 02-28-2009 08:28 PM

lifter tapping?

distortedtj 02-28-2009 11:36 PM


Originally Posted by amerijeep (Post 332389)
lifter tapping?


87YJWrangler 03-01-2009 04:00 AM

My guess is lifter or maybe the fan is hitting so x2 on both above

yjtodd 03-01-2009 04:38 AM

With the engine running take 3 feet of hose and put it to your ear and see if you can locate where the sound is coming from specifically.( Becareful to stay away from the moving parts- fan, pulleys etc.). Jeep in-line engines are notorious for a valve/lifter tapping sound- also try running a higher octane fuel w/ a good fuel cleaner and see if it lessens the sound any. I've also seen water pumps that are going bad make this sound as well. If you can isolate the sound area get back to us and we will give you some more ideas.

Warlock 03-01-2009 09:09 AM

Check the timing chain, mine was hitting the cover because it was worn out and sounded just like a lifter pecking.

cap10 crunch 03-01-2009 12:29 PM

Thanks everyone. You guys have been very helpful. I will check the fan and the lifter later today and I will get back at you guys

cap10 crunch 03-01-2009 01:10 PM

Well i went out and checked it and I had to drive it around the block to get the sound to come back and it's coming from the back of the engine right by the windshield. I feel really dumb asking this but what exactly is a lifter? I didn't see anything that could be making a noise.

tasherrill 03-02-2009 05:23 PM

I've glad someone posted a question on this. Mine starting making the same sound, so I'm going to check out the fan right now.

YjMopower 03-02-2009 05:39 PM

Here is some info about what is a lifter and a possible soultion .If the problem is lifter tapping immediately after cranking the engine, the oil check valve in the cylinder head may need cleaning. Page 17-10 in the shop manual covers the procedure.

The check valve is simply a spring-loaded ball in the oil feed line that prevents oil from draining back while the engine is not running. If this check valve doesn't do its job, the oil lines in the head will be empty, and they will require a few seconds to fill when the engine is started, causing lifter tapping.

The valve is located inside the valve cover, at the lower front corner of the head. After pulling the valve cover and finding the valve, locate the locking screw]\ that goes in from the outside of the head to the side of the valve, and loosen it about four or five turns. Screw (by hand) an M6x40 bolt gently into the valve spring guide (the only part that you can see) until it bottoms, then unscrew it two turns. Pull the spring guide out. Using a magnet, remove the spring and ball. Clean everything, being especially careful to avoid damaging the ball seat down in the hole. The book says to replace the o-ring, and it would be a good idea to do so, especially if it is hardened.

Reassemble. The threaded rod that screws into the side to retain the valve should be tightened to 2.8 ft/lb, which isn't much!

Engine Tapping Noise

Tapping noise from the engine is often caused by a stuck hydraulic lifter. A bad lifter is not necessarily a huge problem and if you are driving an older vehicle you may wish to just ignore the noise if the engine is otherwise perfoming well. Increasing the frequency of your oil changes may help to clear up the issue but if the noise persists you will need to replace the lifter to eliminate the sound.

The above noted, if your tapping sound is accompanied with engine vibrations or backfires, you may be facing a problem more serious than a stuck lifter.

1. Tapping and Vibrating
If the tapping in your auto's engine is accompanied by a persistent vibration or noticeable tremors under load, you may have damaged the rocker-arms or valve push rods. To check the problem you will need to remove the valve covers and visually inspect the arms, rods, and valve stems. Oftentimes the repair is nothing more than replacing the broken rod or arm and bolt.

2. Tapping and Backfire
Though much less likely, if your auto happens to also be backfiring while tapping, you may have a damaged camshaft. This will not be something you should attempt to diagnose yourself, and it will be a fairly costly and laborious repair. If you suspect a bad camshaft, take your auto to a reputable mechanic or dealer and get the cam tested. Before leaving your vehicle, get a full estimate (in writing) and for the repair itself, and for the testing and reassembly should you decide to decline the repair.

If you do go ahead and replace the camshaft, you should also replace all of the lifters as well. Further, this is an opportune time to replace your timing chain or belt.
__and this is what it possibly could look like.
Good Luck ,At least I learned something

cap10 crunch 03-02-2009 05:45 PM

Thanks Mopower! Your post has been very helpful!

jpdocdave 03-02-2009 05:49 PM

slight lifter tapping on jeep straight six is pretty normal. if it isn't real loud, or sharp sounding. honestly the first thing i'd do is buy some oil flush chemical, its really just keroscene. you put it in the oil run the engine for 5 mins. and then change the oil. i've seen it fix noises multiple times, and i used to be a skeptic of it. secondly is keep up on the oil changes. oh yeah, the longer you let it drain after the flush the better.

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