mcaden

Here's the situation. On cool mornings (50-60s), when I start up my 07 JK and start traveling down the road, I hear a clicking noise I believe to be some where in the drivetrain that increases in frequency as I accelerate. The kicker is it only happens for the first few miles or so.

I drive about 20 miles to work each day and I only hear it (very fainitly while driving 45) for the first 2-3 miles. Once the components have heated (it seems) the clicking is gone. I feel that it is something in the drivetrain (I'm thinking the driveshaft but could be way off) because of the location of the noise and the absence of the noise when the transmission is disengaged.

Sorry if this is a newbie question but I am just that. There is a 3.5" Skyjacker lift on it but also a lot of weight with bumpers and such so I was hoping that the driveshaft wouldn't be an issue even know I have heard they can be. It hasn't really been wheeled all that hard. I tend to baby it since I drive it every day.

Any help with this matter that could steer me in the right direction would be greatly appreciated. Thanks.

jkJason

So its like a rotational ticking that corresponds with your speed? I would start by looking at your driveshaft and examine for any grease being thrown out. I'm a bit confused by the lack of noise when the tranny is disengaged? Even in neutral the front and rear driveshafts are still spinning so idk about that one. Other quick checks you can do are making sure nothings rubbing on your tires, no debris in your tread and that your lugnuts are all torqued properly. Hope you figure it out those lil noises can haunt people haha. Anyone else think of something else he can check?

brent_f70

Your tires are developing very mild flat spots when cold. once they heat up....you drive a few miles they round back out. My 35's did not do it but my 37's do. It is b/c you MT have a fairly soft compound.

tpm152

Check your exhaust manifold for cracks! I have heard that is exactly the symptoms of a cracked exhaust manifold. Hairline cracks make a ticking sound (from the exhaust valves opening and closing) until everything heats up at which point the heat expands the metal enough to close the cracks and the ticking stops.

I have a different ticking sound for the first ~5 seconds after I start up my Jeep. From what I can understand it is because of not having an effective anti-drain back valve on my current oil filter. Since our engines use hydraulic lifters the first few seconds before oil reaches the lifters on a cold start they tick from the lack of oil.

river2c

You could be experiencing noisy hydraulic tappets which are normal when the engine is cold. Check your engine oil level and viscosity.

mcaden

Thanks all for the replys. After reading your posts and speaking to a few friends of mine I have a better understanding of what to look for.

jkJason: Yes, the sound corresponds with the speed of the vehicle when it is first started. There is a little bit of grease on the driveshaft near the trans end but it looks liked it just globbed out not really a spray. Sorry, as I said I am new to all this (and to vehicles in general) so I didn't make the connection neutral > driveshaft spins, my bad, thaks for clearing it up

brent_f70: I just rotated the tires last night and will watch them carefully over the next few days. But, I still feel it is something mechanical because it does not sound like a tire click/chirp as I have had that noise before.

tpm152: I will definitely check the exhaust manifold. That just sounds bad so I hope this is not the cause. I do have a cat-back exhaust on there that has been on for over a year now and have been looking to go to headers so maybe this will be my excuse if this is indeed the cuplrit.

river2c: I will also check the oil level. I am almost due up for a change anyways.

Thanks again for all your knowledge since mine is very limited. I really appreciate the help. Also, a friend of mine mentioned that the noise could be chatter from the pressure plate? All new to me so I asked him more about it and he said I might just need to tighten it down. Thoughts?

tpm152

The exhaust manifold isn't bad, depending on how old your Jeep is it may be covered under the warranty. Also from what I've read not only are they the cheapest but I would stick with the stock version of the exhaust manifold because its actually the best performing headers out there (better than the Banks and Gibson aftermarket ones). Someone else want to confirm this?

mcaden

tpm152: I blew through the warranty a while ago. I've got almost 50K on it right now. Lots of traveling long distances,; Atlanta, North Carolina, etc. so the warranty is unfortunately expired (36K). I bought mine about a month before they introduced the Lifetime Powertrain which kinda sucks but oh well.

To all: I did some more investigation while driving it a little this weekend. The temps dropped quite a bit up here. It got down to the lows 40s so I was really able to listen to the issue again. It seemed like the more strain I put on the drivetrain the more intense the noise got, again increasing with my speed. For instance, if I had the tranny engaged but did not have the throttle open, there was no noise (or it was so low I could not hear it). When I gave it any amount of gas the "click" would grow louder and faster with my increase in speed. Any additional thoughts?

I checked the oil level and looked over the exhaust manifold. The oil level is fine and where it should be and what I could see of the manifold looked to be crack free. I am going to get chance to look more closely at it tomorrow and should be able to provide more insight. Any additional comments are welcome and appreciated. Thanks.

iadventure

Did you check your u-joints?

mkjeep

Look over your whole exhaust. Sounds like an exhaust leak . That would explain why after it heats up the sound lessens or goes away. Metal expanding and closing off the leak. To get a good look at the manifold, you have to take the heat shield off. Try this, after it sits over night, pop your hood , crank it , go to the driver side and listen, then to the pass side, if it's more pronouced on one side, most likely a manifoldd is cracked or the manifold is loose. Also, they may both be cracked or loose. My driver side cracked while under warranty. Cheap metal. Started ticking first, then after awhile started to sound like a diesel. Just so you Know, a cracked manifold is very common on jk's and it's very hard to see without taking the heat shield off and getting into some yoga positions.