Good evening all. I have a 2015 jk sport with 71k miles. On startup I had noise that sounded like rocker arm noise that many have documented. I had rockers and lifters changed in both sides. Unfortunately the ticking noise is still there. The noise is apparent as the rpm’s line out and gets quiet after the engine gets up to temp (few minutes). Any pointers or suggestions are appreciated.
2015 JK Engine noise
- Thread starter kbar691
- Start date
Check for exhaust leaks, particularly where the exhaust manifolds mate to the heads
Yes like GP Noir said, usually you might also see some black looking soot where it would be leaking.
If it is the exhaust the reason it seems to get quieter when it gets to temp is the metal will expand and close the gap some.
If it is the exhaust the reason it seems to get quieter when it gets to temp is the metal will expand and close the gap some.
I agree with what both of you are mentioning for sure. I have maybe thought it could be exhaust. The videos I have found with exhaust leaks don’t sound exactly like this but that could be a function of where the leak is. I will look around the manifolds real close. The noise really sounds like the rocker and noise but like I said…..they were all replaced. We inspected the ones that came out and they didn’t show signs of failure. Very odd for sure.
I had an 87 Cherokee that developed a rod knock after I installed a set of Borla headers. Turns out the "rod knock" was an exhaust leak that developed when one or two of the header bolts loosened. Noise went away after re-torquing the header bolts.
If the noise is a manifold leak, a new exhaust gasket might be needed.
If the noise is a manifold leak, a new exhaust gasket might be needed.
The jk manifolds love to crack too, which could be the problem.
Well I cannot find an exhaust leak. The strange thing is as soon as you step slightly on the gas the noise goes away. I’m at a loss. Maybe something in the variable timing???
When you removed the valve cover, the PCV is attached to the rear side of the valve cover with 2 T-25 screws. If they aren't tight when you insert the PCV and install the valve cover, the PCV will make noise. The screws are pretty much blind, too.
Also, the rocker may not look bad, but the roller bearing will sometimes go, so you gotta check for any play there as well.
Also, the rocker may not look bad, but the roller bearing will sometimes go, so you gotta check for any play there as well.
When we replaced I wholesale changed them all. Rockers and valve lash adjusters. The noise sounds like it is coming from the PCV area. Is it possible that thing is going bad and needs replaced? It made the same noise before rebuilding the valve train.
Had a recommendation to replace the purge valve. That didn’t help. Such a weird issue. No error codes. All rockers and lash adjusters replaced. Still ticking. I cannot find an exhaust leak. The weird thing is I have been watching oil pressure. When the engine comes to idle on startup as the pressure and rpm comes down the tick starts. Oil pressure between 30-40 psi it will tick. After you drive it and get it all warmed up the oil pressure drops to 27-28 psi. No tick. I am so confused. Next stop light the oil pressure may be 30 psi and you hear the tick. I would like to think if it was a cylinder head issue or a major mechanical issue with the engine the tick would always be there???
Threepointsix
JK Enthusiast
Intermittent is odd, for sure. As most technicians say, it's a complex engine.
Post up a vid, if you can. Im curious to hear this tick sound. Sometimes my engine can sound ticky, but Im starting to think Im over-listening thinking there's something wrong, when there isn't.
Post up a vid, if you can. Im curious to hear this tick sound. Sometimes my engine can sound ticky, but Im starting to think Im over-listening thinking there's something wrong, when there isn't.
Out on spring break right now. Dropped it off at my mechanic for an alignment after putting on some new shoes. I am sure he will tinker with it. If he doesn’t figure it out and it still ticks I will certainly do so. It is weird though. You can stand there listening and the tick will slowly dissipate then come right back. I am wondering if it has something g to do with a bad spot on a cam and variable timing.
Threepointsix
JK Enthusiast
Nice! Enjoy Spring break
Good theory, but wouldn't that mean the tick would be cyclical and have a pattern?
I am certainly pulling at straws!!Nice! Enjoy Spring break
Good theory, but wouldn't that mean the tick would be cyclical and have a pattern?
So the mechanic has it taken apart. There is no visible damage on the lines of the cams. Some discoloration but no grooves or gouges like I have seen some. You can feel a little uneven area in 2 lobes on the intake cam on the passenger side. He took a feeler gauge and couldn’t slide it between any lobe and rocker. At a total loss.Nice! Enjoy Spring break
Good theory, but wouldn't that mean the tick would be cyclical and have a pattern?
Threepointsix
JK Enthusiast
And all the rockers and lash adjusters look good / sound (don't rattle) tight? Im guessing the mechanic is rotating that timing to check them all? Because depending on where the cams are positioned they can hold a damaged rocker follower tight in its place.
Why not just say "eff it" while in there and change that passenger side intake cam?
Correct. Rotated through all positions and the 0.005 feeler gauge would not fit under any lobe. I am going to certainly replace that cam. I’m wondering if I should do both on that side. Or heck, really say “eff it” and replace them all. If I do that then I certainly won’t be going back into the valve covers for that. Thoughts?
Threepointsix
JK Enthusiast
Ok, good then you know well enough that they're solid.
On changing everything out: didn't you have them changed already with the exception of the cams? Maybe Im thinking another thread with a different JK. But if you already did, I wouldn't bother. However, when that cam comes out I'd ask the mechanic to literally pull and check the rocker rollers anyway since the cam is out. Never hurts. If it so happens that one of them is indeed failing or collaped, then maybe then it justifies popping all four off and inspecting those rollers and changing as needed.
Tough one on, though. Easy to say 'since you're in there, may as well change them all', but if you change them recently and the mechanic is confident that the present are fine, I wouldn't add the additional cost.
Hope this corrects the sound because Im telling you, I really suspect a weak lash adjuster on my passenger side and I too am planning on going in this Spring to check for myself.