Tough to diagnose ticking noise


Ledfoot Lou

Member
Joined
Feb 15, 2020
Messages
82
Location
Oklahoma City
I bought my first TJ about a month ago. A super clean 2005 sport with 83k miles a 4.0 engine and 6 speed transmission. Almost immediately I noticed a ticking noise from inside the cab that was very consistent and varied with RPM. It doesn’t tick at idle, but starts after about 1500 rpm, in neutral and in gear, with or without the clutch pushed. I thought for sure exhaust leak and did a shop vac and soapy water test. Did not find any leaks. I replaced the opda with a new crown unit, which also did not solve it. I brought it back to the dealer I bought it from, who only sells TJ’s, and their mechanic spent 4 days with it but could not locate the noise. It could just be the engine itself, but he mentioned having other TJ’s on the lot and them not being this loud. Any ideas what it could be? Here’s some other things I’ve tried with no change.

Removed the belt and ran the engine.
Changed the spark plugs.
Checked torque on the rockers, and looked for wear.
Bought a new injector and rotated it through all 6 spots.

I’ve used a stethoscope everywhere and can’t seem to find any one location that is obviously making the noise. You cant really hear it under the hood because the air rushing from the fan drowns it out, but when you close the door in the cabin, it is very distinct.
Has anyone else experienced this?
 
Last edited:

Goatman

TJ Expert
Supporting Member
Joined
Apr 23, 2019
Messages
4,306
Location
Upstate NY
Lift the hood at night. It could wire arcing to ground. I'm assuming the mechanic has ruled out obvious things like lifters. It could also be something wrong with the clutch. A piece of crap or broken spring. If this only happens when moving it could be something stupid like barbed wire wrapped around a drive shaft (happens more than you think) is the tick clearly rpm specific or mph specific or changes depending on what gear you are in? Can you tell forward or rear?
 
OP
L

Ledfoot Lou

Member
Joined
Feb 15, 2020
Messages
82
Location
Oklahoma City
Thats a good idea, I’ll see is if the coils are arcing to ground. However I don’t really have wires, it has the coil packs in one long rail that mount to the head.
You can replicate the noise in park, with or without the clutch pushed in. Hot or cold. I think that rules out the transmission, driveshaft, or clutch disc. It’s rpm specific in that it doesn’t do it at idle, once the engine gets rev’d up you hear it, and it will change speed with the rpms.
It sounds like when you put a playing card in bicycle spokes. Not a clunking, clanking, or any obviously major engine issue.
 

creecer

Member
Joined
Feb 26, 2019
Messages
26
Location
Woodstock, GA
Thats a good idea, I’ll see is if the coils are arcing to ground. However I don’t really have wires, it has the coil packs in one long rail that mount to the head.
You can replicate the noise in park, with or without the clutch pushed in. Hot or cold. I think that rules out the transmission, driveshaft, or clutch disc. It’s rpm specific in that it doesn’t do it at idle, once the engine gets rev’d up you hear it, and it will change speed with the rpms.
It sounds like when you put a playing card in bicycle spokes. Not a clunking, clanking, or any obviously major engine issue.
Check the exhaust again, but this time smoke check it. If there is a leak, you'll find it for sure.
 

Goatman

TJ Expert
Supporting Member
Joined
Apr 23, 2019
Messages
4,306
Location
Upstate NY
Use a long screwdriver on various places on the motor. Put your ear to the other end like a stethoscope. It has the potential to be a rod or lifter. You should be able to really narrow down the location this way.
 
OP
L

Ledfoot Lou

Member
Joined
Feb 15, 2020
Messages
82
Location
Oklahoma City
Use a long screwdriver on various places on the motor. Put your ear to the other end like a stethoscope. It has the potential to be a rod or lifter. You should be able to really narrow down the location this way.
I’ve got a mechanics stethoscope and have been using it everywhere. You hear it faintly everywhere, but nothing stands out as being the obvious cause. Also, doesn’t it seem like the ticking is 1 to 1 with the engine speed? Wouldn’t that mean it’s not a lifter, rocker, or valve since they run at half engine speed?
 

Aloha Joe

TJ Enthusiast
Joined
Oct 31, 2018
Messages
133
Location
Honolulu, HI, USA
Does the noise eventually stop /go away after you've been driving a bit? Is it possible there's a slight exhaust leak that only develops when the engine is under load (as in, something moves just enough that you start to notice it?) I'm just asking because I've fought small exhaust leaks in my 05 Rubicon and they sound just like that.
 
  • Like
Reactions: SecondChanceTJ
OP
L

Ledfoot Lou

Member
Joined
Feb 15, 2020
Messages
82
Location
Oklahoma City
Does the noise eventually stop /go away after you've been driving a bit? Is it possible there's a slight exhaust leak that only develops when the engine is under load (as in, something moves just enough that you start to notice it?) I'm just asking because I've fought small exhaust leaks in my 05 Rubicon and they sound just like that.
It never goes away. Hot or cold it always sounds the same. Except it’s not present at idle, only after rev’d up to like 1300-1500 rpm.
 
OP
L

Ledfoot Lou

Member
Joined
Feb 15, 2020
Messages
82
Location
Oklahoma City
Pulled the transmission to look at the clutch as there was a definite noise coming from the top of the bellhousing. Clutch looked fine, but i replaced it anyway. I did find the inner shift boot torn, and upon replacing that it seems much quieter inside the cab. Thinking the ticking might be normal engine noise now. Haven't ridden in too many other jeeps to compare to.

IMG_4970.jpg
 

Rubicon John

TJ Enthusiast
Joined
Mar 12, 2020
Messages
778
Location
Atlanta
Sounds similar to a lot of 4.0s I’ve heard.

As a side note, when I bought mine with 186k on it, it had a nasty tick that would come and go. There was no way to make it come and go, it would make noise whenever it wanted, whether idling or under a load. I thought it was a sticky lifter for sure and even ran the engine with the valve cover off to get a better listen. I knew it was on cyl 5 or 6 but it was deeper than I could see with the cover off


I did a BG intake cleaning service and ran some chemical through the throttle body with the engine running.

The ticking has since stopped and hasn’t come back. I’m summing it up to a carbon deposit on an exhaust valve that was making noise when in the right position, but spun around as it pleased, causing the noise to come and go.

I’m not saying this is your issue but I certainly had good luck going after some carbon that I knew would be in there. I didn’t even realize that was my noise until it was said and done.
 
OP
L

Ledfoot Lou

Member
Joined
Feb 15, 2020
Messages
82
Location
Oklahoma City
It seems a lot of people have ticks that come and go, and that doesn't really fit my symptoms. This noise is there as long as you're above idle RPM, hot, cold, in gear, out of gear, clutch in, clutch out, driving down the road, sitting in the driveway, it doesn't matter.

I think the big thing is that I've got a hardtop and full doors. If i even just crack the window while sitting in the driveway the noise of the engine and fan overcome the ticking noise. This makes me think a lot of jeeps probably sound like this, but with a soft top, half doors, or no top there's too much noise to really hear it.
 

Rubicon John

TJ Enthusiast
Joined
Mar 12, 2020
Messages
778
Location
Atlanta
It seems a lot of people have ticks that come and go, and that doesn't really fit my symptoms. This noise is there as long as you're above idle RPM, hot, cold, in gear, out of gear, clutch in, clutch out, driving down the road, sitting in the driveway, it doesn't matter.

I think the big thing is that I've got a hardtop and full doors. If i even just crack the window while sitting in the driveway the noise of the engine and fan overcome the ticking noise. This makes me think a lot of jeeps probably sound like this, but with a soft top, half doors, or no top there's too much noise to really hear it.
I was just pointing out that a top end cleaning freed some crud up. Might not be a bad idea to try out. It won’t hurt anything.
 

AndyG

TJ Guru
Lifetime Supporting Member
Joined
Jul 30, 2018
Messages
7,214
Location
Alabama
Spray penetrant on the 4 pre cat bolts when cold, let soak, break free and tighten and you will solve the problem.

It is amazing how hard it is to isolate noises. A TJ is mechanically dense , and that makes it harder .
 
  • Like
Reactions: Aloha Joe
OP
L

Ledfoot Lou

Member
Joined
Feb 15, 2020
Messages
82
Location
Oklahoma City
Spray penetrant on the 4 pre cat bolts when cold, let soak, break free and tighten and you will solve the problem.

It is amazing how hard it is to isolate noises. A TJ is mechanically dense , and that makes it harder .
I tried tightening the pre cat bolts, and still had a slight exhaust leak there. So I added some exhaust sealer to the joint, replaced the bolts and retightened. No more exhaust leak, but still have the ticking.
 
  • Like
Reactions: AndyG
OP
L

Ledfoot Lou

Member
Joined
Feb 15, 2020
Messages
82
Location
Oklahoma City
How's your oil pan look? I smashed mine and it ticked from the connecting rod grinding material off of the support girdle.

Probably not your issue but it makes a ticking noise.
Wow! I noticed there is a small dent in the oil pan. I’m definitely going to pull the pan and take a look. Thanks for the idea!
Edit: I went to look at the oil pan and it seems the dent is only in the sump portion. I don’t think the crank is hitting that.

6ECC6328-7603-4D82-8FCF-DC371C9E9FCE.jpeg
 
Last edited: