Will a 2003 3.7L be a direct swap to a 2002 3.7?

Hi all,

been searching for days, figured I'd try a post here. I have a 2002 Liberty 3.7L here that the previous customer put a 2004 motor and changed the reluctor ring to make it work. it has a knock now, and I have a 2003 3.7L out of a good donor here.

Is this a direct swap? Half the articles I say, say absolutely, but a few others and a friend say we'll still need to change out the tone and reluctor rings from the 2004 into the 2003 to get it to work in the 2002.

Any ideas before I start tearing motors apart?

rainbowauto said:

Hi all,



been searching for days, figured I'd try a post here. I have a 2002 Liberty 3.7L here that the previous customer put a 2004 motor and changed the reluctor ring to make it work. it has a knock now, and I have a 2003 3.7L out of a good donor here.



Is this a direct swap? Half the articles I say, say absolutely, but a few others and a friend say we'll still need to change out the tone and reluctor rings from the 2004 into the 2003 to get it to work in the 2002.



Any ideas before I start tearing motors apart?

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I'm guessing that they changed by the year, at least need to change the reluctor ring I would bet. Call a wrecking yard and ask them, they would have the books to know.

Sent from my Moto Z (2) using Tapatalk

Depends on the computer in the 02 and the donor 03. For KJs the changeover year was 04 (JTEC to NGC) so an 03 to an 02 should be a direct swap. The 04 could have either so the one the previous person used must have been out of a later 04 NGC vehicle.

http://www.jeepkj.com/forum/f202/engine-swap-overview-53270/

02/03 are the same. I just did a swap last month

Aceofspades said:

02/03 are the same. I just did a swap last month

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I hope to never have to verify this. lol.

Transmission... meh.. possibly. No real danger signs, but then again with that, I'd either just rebuild or get a usable jy unit.

JasonJ said:

I hope to never have to verify this. lol.

Transmission... meh.. possibly. No real danger signs, but then again with that, I'd either just rebuild or get a usable jy unit.

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Yeah it’s been chooching coolant for probably most of 2018 without me noticing anything in the oil. Then gasket finally gave way a little more causing misfires and eventually no start at all.
Come to think of it , would explain why I couldn’t seem to seal my rad hoses and excessive buildup in the oil cap.

My buddies 3.7 popped and it was instant milkshake oil. Weird.

Aceofspades said:

Yeah it’s been chooching coolant for probably most of 2018 without me noticing anything in the oil. Then gasket finally gave way a little more causing misfires and eventually no start at all.
Come to think of it , would explain why I couldn’t seem to seal my rad hoses and excessive buildup in the oil cap.

My buddies 3.7 popped and it was instant milkshake oil. Weird.

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Figures, don't it?

On one hand, if I had the space, it wouldn't bother me to acquire a parts yard drivetrain for the KJ and go through and full rebuild both trans and engine, then soak it in packing grease and oil, shrink wrap it, and stick it in the corner of the garage on a pallet... and with any luck, it'd just sit there.. but if the time ever came...

I tend to enjoy rebuilding drivetrains, but not under a time crunch or when the vehicle is laid up and undriveable.

Aceofspades said:

My buddies 3.7 popped and it was instant milkshake oil. Weird.

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That's what my 02 did a few years ago.

I'm with JasonJ. I keep thinking of getting a jy engine and rebuilding it to stick in the corner of the garage and I don't even have 70k on mine... :emotions34:

It comes down to timing for me. I could have prepared myself better if the yellow sludge under my oil cap wasn’t thought to be just cold weather/short trips scenario. My instinct screamed head gasket but everything was fine. Oil. No visible smoke. Coolant loss couldn’t be controlled due to reservoir leaking and being replaced , radiator cracked and replaced and new hoses constantly leaking.


Ideally I wanted the latest 3.7 with little miles as possible- if I had known ahead of time I could have prepared one for the swap.

Why not just do the head gasket ? 170k this was the better choice I think

So you had no issues putting the 2003 in the 2002? and you did not have to swap the intake or the exhaust manifolds.

Aceofspades said:

02/03 are the same. I just did a swap last month

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Hi was wondering if you by chance knew what all year Jeep Liberty motors would be a direct fit for me to use in my 2002 Jeep Liberty 3.7 l V6 four-wheel drive limited edition my motor blew up in it I'm just looking for the quickest way to get it back on the road. Thank you so much in advance

02-03 yes. Finding another 19 year old used motor may not be the best solution for longevity.
Another option with warranty would be to contact your closest Jasper Engines.
They have so many location across the USA and can ship & or install.
Their engines utilize many quality updated parts in their builds, and are known for reliability.
Some of our members have chosen this route with very good success.

Plus if it fails the shop that installed it has to honor the warranty (from what I understood)