How long do 4.0s really last?
CF Veteran
Joined: Nov 2011
Posts: 2,401
Likes: 0
From: Montpelier, Ohio
Year: 92
Engine: 4.0
Ive ran a few 4.0's over 300k with no problems, but almost half million is quite impressive. !!
CF Veteran
Joined: Oct 2011
Posts: 1,268
Likes: 1
From: Bakersfield CA
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Thanks.... coming up on 424 pretty soon. There's a few out there with more on them someones got 563,000 on an 87 I believe, and an old CJ5 has 600,000 plus with the old 4.2
keep rollin
Member
Joined: Nov 2016
Posts: 124
Likes: 0
Year: 2000
Model: Cherokee
Engine: 4.0
CF Veteran
Joined: Jul 2012
Posts: 3,686
Likes: 6
From: Hudson, FL
Year: 1999
Model: Cherokee
Engine: 4.0L Inline 6
IMO, when people say "300k without any problems," what they really mean is "300k after several hundreds or thousands worth of repairs later."
Mine was pristine taken care of, and that was my story at just 170k miles. Probably would have kept on running, but it certainly did have a lot of problems.
I don't think all the sensors and stuff work too great after long service life, but if you keep up on them and replace stuff as it fails and keep the oil changed, the engine itself lasts a very long time and surely 300k is no stranger to the 4.0.
Mine was pristine taken care of, and that was my story at just 170k miles. Probably would have kept on running, but it certainly did have a lot of problems.
I don't think all the sensors and stuff work too great after long service life, but if you keep up on them and replace stuff as it fails and keep the oil changed, the engine itself lasts a very long time and surely 300k is no stranger to the 4.0.
Last edited by thatXJguy; Dec 3, 2016 at 03:10 PM.
CF Veteran
Joined: Oct 2013
Posts: 2,097
Likes: 12
From: Tarpon Springs, FL / Denver, CO
Year: '98
Engine: 4.0 I6
IMO, when people say "300k without any problems," what they really mean is "300k after several hundreds or thousands worth of repairs later."
Mine was pristine taken care of, and that was my story at just 170k miles. Probably would have kept on running, but it certainly did have a lot of problems.
I don't think all the sensors and stuff work too great after long service life, but if you keep up on them and replace stuff as it fails and keep the oil changed, the engine itself lasts a very long time and surely 300k is no stranger to the 4.0.
Mine was pristine taken care of, and that was my story at just 170k miles. Probably would have kept on running, but it certainly did have a lot of problems.
I don't think all the sensors and stuff work too great after long service life, but if you keep up on them and replace stuff as it fails and keep the oil changed, the engine itself lasts a very long time and surely 300k is no stranger to the 4.0.
My dad had a ZJ. Neglected the hell out of the thing. I think we changed spark plugs 3 times in 400,000 miles. The lower radiator hose was factory original somehow.
Original head gasket. It was a ZJ, so the transmission was garbage and rebuilt 2 or 3 times, but the motor was still in good condition when he sadly cash for clunkered it at ~425,000 miles.
I have a picture of it at 350k somewhere I can post up. Pops loved that thing more than he loved me, but he somehow got a $4,000 credit out of it thanks to Obama. Can't really blame him, but he did take it harder than I thought he would when it finally came time to send her to junkyard, lol
Last edited by investinwaffles; Dec 7, 2016 at 12:03 AM.
CF Veteran
Joined: Jul 2012
Posts: 3,686
Likes: 6
From: Hudson, FL
Year: 1999
Model: Cherokee
Engine: 4.0L Inline 6
Not necessarily true.
My dad had a ZJ. Neglected the hell out of the thing. I think we changed spark plugs 3 times in 400,000 miles. The lower radiator hose was factory original somehow.
Original head gasket. It was a ZJ, so the transmission was garbage and rebuilt 2 or 3 times, but the motor was still in good condition when he sadly cash for clunkered it at ~425,000 miles.
I have a picture of it at 350k somewhere I can post up. Pops loved that thing more than he loved me, but he somehow got a $4,000 credit out of it thanks to Obama. Can't really blame him, but he did take it harder than I thought he would when it finally came time to send her to junkyard, lol
My dad had a ZJ. Neglected the hell out of the thing. I think we changed spark plugs 3 times in 400,000 miles. The lower radiator hose was factory original somehow.
Original head gasket. It was a ZJ, so the transmission was garbage and rebuilt 2 or 3 times, but the motor was still in good condition when he sadly cash for clunkered it at ~425,000 miles.
I have a picture of it at 350k somewhere I can post up. Pops loved that thing more than he loved me, but he somehow got a $4,000 credit out of it thanks to Obama. Can't really blame him, but he did take it harder than I thought he would when it finally came time to send her to junkyard, lol
Newbie
Joined: Oct 2018
Posts: 8
Likes: 0
Year: 1999
Model: Grand Cherokee (WJ)
Engine: Amc inline 6 4.0l
My WJ is one of the 1999 inline 6 sporting the 0331 head, I think that each 1999 WJ built in Austria for EU market has this ill fated cyl head. Anyway at 194k km (or 120k miles for you imperial system aficionados) the car is running smoothly with no crack symptoms.