Help.Knock or sputtering in 4.0 with cam

Tycarver

TJ Enthusiast
Joined
Sep 5, 2019
Messages
370
Location
Florida
I had a new engine put in my Jeep last year. A remanufactured 4.0 with a stage 2 cam. ( was only a few bucks more so why not) my exhaust manifold was cracked then but we just put it back on anyway. I changed the exhaust manifold last week and since I have developed a click or sputter sound coming from the engine. ( I’ll add a video today when I drive it) it happens at idle very lightly and then while driving you can definitely hear it when the engine is under load. Coasting at one speed it almost completely goes away. Becomes way quieter then my tires. I have tried looking stuff up online but I can’t find anything other then lifter problems that go away when the engine is warm. So I’m wondering if
A. I installed the exhaust manifold slightly off and it’s still and exhaust leak just not as bad
B. An internal engine problem that I need to go have checked out
C. Normal behavior for a cam in an engine ( I’ve never had a larger cam put in)
D. Something else completely.
Thanks everyone in advance.
 
Are you still having this issue or is it resolved?

I had a similar-sounding issue (I did watch the video you uploaded, and mine sounded pretty much the same) ~3 years ago that was caused by a visibly cracked exhaust manifold, so I had that replaced. Then about 1 year ago it came back, and I was pretty P.O.'d since I had just paid for that new exhaust manifold + labor and it was doing the same thing again.

I took it to a different mechanic from the one that had done the manifold replacement (I stopped using them because they wouldn't call me with a diagnosis or to tell me it was fixed... I had to be the one to call them, every time), and they said it was the exhaust manifold gasket this time. It sucks, but replacing that did fix the problem.

So, if you did the manifold replacement yourself, first of all good work, because the labor is $300+ according to RepairPal, and that roughly matches what I paid for just the labor each time. The gasket is cheap, though, so if you're paying $0 + your time for labor and ~$40 for the gasket, it's not that expensive to go back in and replace the gasket.

If you already fixed it and it wasn't that, what was it? Thanks!
 
Are you still having this issue or is it resolved?

I had a similar-sounding issue (I did watch the video you uploaded, and mine sounded pretty much the same) ~3 years ago that was caused by a visibly cracked exhaust manifold, so I had that replaced. Then about 1 year ago it came back, and I was pretty P.O.'d since I had just paid for that new exhaust manifold + labor and it was doing the same thing again.

I took it to a different mechanic from the one that had done the manifold replacement (I stopped using them because they wouldn't call me with a diagnosis or to tell me it was fixed... I had to be the one to call them, every time), and they said it was the exhaust manifold gasket this time. It sucks, but replacing that did fix the problem.

So, if you did the manifold replacement yourself, first of all good work, because the labor is $300+ according to RepairPal, and that roughly matches what I paid for just the labor each time. The gasket is cheap, though, so if you're paying $0 + your time for labor and ~$40 for the gasket, it's not that expensive to go back in and replace the gasket.

If you already fixed it and it wasn't that, what was it? Thanks!
My exhaust headers had actually burned through the new gasket I put on. Got a new one put it on and seems like the problem is slowly coming back as well.