A couple of weeks ago, I started noticing a ticking/knocking noise while driving home from a trip that became apparent around 1700 RPM, peaked at 2000 RPM, and was drowned out by engine/wind noise above that. Engine temperatures were perfect and oil pressure was within what I would call normal (at least normal for the past 15,000 miles I've driven it). I popped the hood when I got home and the noise scared me enough to not drive it, and oil level was low (checked before the trip and it was fine). I parked it, and life got in the way for the next few weeks.
I'm finally getting around to trying to diagnose it, and as you're probably aware, every youtube video for 4.0 engine knock either doesn't record the actual noise, or it has 15 different diagnoses from 15 different people who "drove their brother's jeep once." I've found similar-sounding videos where the culprit was everything from lifter/rocker noise, to CPS, to exhaust leak, to piston slap and broken skirts. I wanted to post here to see if anyone had an idea before I get the time to tear this down and look at everything.
What I notice:
I was planning to take apart the top end and see if anything had excess play or was stuck/collapsed, but have not yet had the time. I live in an apartment and am not "supposed" to work on a vehicle, so anything bottom end I will need to take it to a friend or a shop. Is it worth taking the top apart when I get time, or should I be expecting bottom end and just drive it to a better working location while it's still in one piece? (trailer is an option, but I do have to get it out of a parking garage). Any thoughts or suggestions for further diagnosis are appreciated
I'm finally getting around to trying to diagnose it, and as you're probably aware, every youtube video for 4.0 engine knock either doesn't record the actual noise, or it has 15 different diagnoses from 15 different people who "drove their brother's jeep once." I've found similar-sounding videos where the culprit was everything from lifter/rocker noise, to CPS, to exhaust leak, to piston slap and broken skirts. I wanted to post here to see if anyone had an idea before I get the time to tear this down and look at everything.
What I notice:
- When driving, I only hear it nearing 2000 RPM. Always under acceleration, never when I'm constant at 2000 or decelerating through it
- Noise happens cold, hot, does not seem to change with temp
- From under the hood, it sounds noiser on the driver side
- Using a mechanics stethoscope, it sounds loudest on the valve cover in the back half of the engine, but to the ear, the bottom of the engine sounds louder. Oil pan picks up no noise with stethoscope
- No metal flakes in oil or magnetic particles.
I was planning to take apart the top end and see if anything had excess play or was stuck/collapsed, but have not yet had the time. I live in an apartment and am not "supposed" to work on a vehicle, so anything bottom end I will need to take it to a friend or a shop. Is it worth taking the top apart when I get time, or should I be expecting bottom end and just drive it to a better working location while it's still in one piece? (trailer is an option, but I do have to get it out of a parking garage). Any thoughts or suggestions for further diagnosis are appreciated