4.0 engine noise

Mjv

TJ Enthusiast
Joined
Dec 30, 2019
Messages
229
Location
Michigan
I've spent most of my life wrenching. I have learned the importance of fit and finish. The effects of proper lubrication and cooling. And most importantly proper maintenance. Please tell me why the 4.0 is so darn noisy!🤔
 

Chris

Administrator
Staff Member
Joined
Sep 28, 2015
Messages
45,043
Location
Salem, Oregon
4.0s are notorious for lifter tick, especially during cold starts. Usually it goes away after 30-45 seconds.

In addition, at this age they often develop exhaust leaks and cracks in the exhaust manifold, which will definitely add a lot of noise.