Originally Posted By: jeepman3071
Originally Posted By: Nick1994
Any old 10w30 would work fine. My 4.0L sits a lot, only 3,000 miles a year or so.
If you're gonna drive it in the freezing cold, use a 5w30.
This.
I have a few UOAs floating around here from my 4.0L Jeep. The quietest running and lowest iron wear numbers I have seen have been from plain ole' Pennzoil conventional 10w30.
I also have some pics floating around from my friend's 2000 Cherokee 4.0 with the valve cover off. It had Pennzoil conventional from new, and the valve-train is spotless.
I used 10w30 for a while, but I would get what I call "OCI shock." My Jeep would tick even when hot for about 2000 miles into an oil change. 10w40 stopped that and I kept the oil filter the same. Maybe that is just a high mileage thing?
Wish I could say my under valve cover was spotless. It's covered in varnish.
https://bobistheoilguy.com/forums/ubbthreads.php/topics/3624423/Jeep_4.0_under_valve_cover
Originally Posted By: Nick1994
Any old 10w30 would work fine. My 4.0L sits a lot, only 3,000 miles a year or so.
If you're gonna drive it in the freezing cold, use a 5w30.
This.
I have a few UOAs floating around here from my 4.0L Jeep. The quietest running and lowest iron wear numbers I have seen have been from plain ole' Pennzoil conventional 10w30.
I also have some pics floating around from my friend's 2000 Cherokee 4.0 with the valve cover off. It had Pennzoil conventional from new, and the valve-train is spotless.
I used 10w30 for a while, but I would get what I call "OCI shock." My Jeep would tick even when hot for about 2000 miles into an oil change. 10w40 stopped that and I kept the oil filter the same. Maybe that is just a high mileage thing?
Wish I could say my under valve cover was spotless. It's covered in varnish.
https://bobistheoilguy.com/forums/ubbthreads.php/topics/3624423/Jeep_4.0_under_valve_cover
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