3.9L reliability question
some of them are magnums, it doesnt matter, they're the same engine except a different intake manifold that supports MPI, plus the MPI system. I think the reason most of them are pre-magnum engines is simply due to the fact it takes a while to rack up that many miles. Keep in mind anything 92+ is a magnum 3.9 but even pre-mags had all the same internals, just no MPI.
Rookie
Joined: Sep 2008
Posts: 75
Likes: 0
From: south west ohio
the most recent ones are at the end.
other than mpi the only other change (other than head flow) was roller lifters.
with mpi being more precise and roller lifters being easier on the cam, when some of these 3.9L's get old enough you are going to see alot with high mileage.
what year was the 3.9L named the magnum? 1991?
other than mpi the only other change (other than head flow) was roller lifters.
with mpi being more precise and roller lifters being easier on the cam, when some of these 3.9L's get old enough you are going to see alot with high mileage.
what year was the 3.9L named the magnum? 1991?
Last edited by x99j; Dec 8, 2008 at 08:19 PM.
Champion
Joined: Jun 2008
Posts: 3,300
Likes: 2
From: Plattsburgh, NY
Apparently i got the short end of the stick on my 3.9. It was the worst vehicle I have ever owned. I took care of it and it blew up a week after I got it with only 112k on the clock and its already ticking and what not at 135k. Just from my own experience it was a horrible engine, but from reading what you guys say, it was probably just a lemon.
Record Breaker
Joined: Jul 2007
Posts: 2,040
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From:
3.9l
moe in wichita ks
as you all know the 3.9 has a lot in common with the 318. i was looking up crank specs and found out that the dia of the main bearings and crank pins of the 3.9 and 318 date all the way back to 1955. i remember in 1966 chrysler said they were going to change the heads on the 318 in 1967 and make the camshaft to hydraulic, my dad and i thought this was realy a bad idea. it turned out to be great change. years later we joked about how wrong we were.
as you all know the 3.9 has a lot in common with the 318. i was looking up crank specs and found out that the dia of the main bearings and crank pins of the 3.9 and 318 date all the way back to 1955. i remember in 1966 chrysler said they were going to change the heads on the 318 in 1967 and make the camshaft to hydraulic, my dad and i thought this was realy a bad idea. it turned out to be great change. years later we joked about how wrong we were.
THE ULTI-MOD
Joined: Jan 2007
Posts: 19,797
Likes: 36
From: Union NJ
yea the 3.9 is a ****ing tank, mine had 200k(was a 98) on it when i got rid of it, still ran like it was new, and it would outrun my dads new(03) dak w/ less miles(his truck also had the 3.9)