I have been chasing a tapping/clacking noise on a 2004 4.0 TJ. There is absolutely no tapping on first startup of the day. It runs like a brand new engine. A couple minutes after starting when the fast idle drops the clacking begins. I can drive it and the noise pretty much goes away and stays that way until I shut the jeep off. When I restart it a few minutes later the clacking comes back on startup. I had the top end rebuilt a few months back and everything was fine until oil change 3000 miles after rebuild. 10w-30 was put in it and the clacking began at that time. I have removed the belt, and the noise is still there. I've tried different oils, additives, and filters but little change. I am just at a loss on what this could be. Anyone else experienced no bad noises on cold start, then clacking that gets pretty much quite after driving and comes immediately back at warm startup? Like I said, if it sets overnight there is no noise on cold startup.
Engine tapping noise a couple minutes after cold start
- Thread starter gbn04
- Start date
Grab a stethoscope or big screwdriver and start listening to the engine until you locate where it's coming from.
I've listened with the stethoscope. Noise seems loudest at side of block toward front of motor. Can here it through the front flange of the exhaust manifold when putting the stethoscope on the manifold. I'm guessing one or more lifters are acting up.
Thanks I will give that a try. Here is video showing how quite the motor is on cold start. And when the noise starts up.
brewtus98
TJ Enthusiast
Daughter's '03 does the same. I believe after reading a BUNCH of threads that it is a lifter issue - sticky and not pumping up....
Hard to hear the noise in the video. Sounds like it could be a timing chain wear pad. Does the noise kind of beat to its own drum or is smooth and steady like a sewing machine?
I'd check the timing chain, just put a breaker bar on the crank and move it back and forth. The play in the chain will be very obvious if it is worn. Seems like the chain to me from the videos. It causes the camshaft to bounce around uncontrolled in the block at the piston height generally at idle so it sounds like a muffled knock instead of the chain rattle most people expect. It's easy to check even if it isn't the issue.
If you have a sticky lifter, that's usually pretty easy to fix. Right before you change your oil, dump in a quart of your chosen poison and do some light driving and/or idling for about 30 minutes, then change the oil. I've done it with Seafoam, older guys will say to use diesel fuel, but there are commercially available "engine flush" products that will work.
What makes these things a little bit hard to figure out is they will run forever with a variety of little problems it seems like at the same time I have heard them purr like a kitten and of course we all love that-
I’m not trying to excuse anything but I have heard the statement that these are somewhat noisy engines and probably compared to a lot of modern vehicles that’s a true statement
I’m not trying to excuse anything but I have heard the statement that these are somewhat noisy engines and probably compared to a lot of modern vehicles that’s a true statement
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Beats to its own drum. Now that you point it out. Kind of sounds like shaking the ball in a empty paint can, faster and slower without me giving any gas. I will post another video when it the loudest.
I have the same noise,it sounds like it’s in between the engine and the radiator.starts after it warms up