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03 TJ engine swap

2K views 14 replies 7 participants last post by  Zorm 
#1 ·
Alright, daughter's 03 TJ broke the timing belt yesterday and screwed up the valves and maybe piston damage, engine is a 2.4L. Finding another one is an option, which i have feelers out for.

The other is to swap in my 4.6 stroker. I know I will need to change the motor mounts, ECM and engine wire harness (from another 03 or comparable years). I picked up a NV3550 5 speed for my jeep and would be using that.

So to those that may have done this, how much time. I still need to get the bell housing for the NV3550 and maybe a higher psi fuel pump for her jeep if I go this rout. ( higher psi because I am driving ford 23lb injectors and a ford mustang throttle body)

One question is, would the xfr case from the 5 speed mated to the 4 cyl, bolt up to the 5 speed for the 4.0?
If I get the 4.0 engine harness, what else would I need to do as far as wiring (under dash and gauge stuff)

Anything else I might be missing.

And please don't say " sell and get the 4.0 jeep" or " should have not bought the 4 cyl jeep" Right now I just need to get her back on the road so keep those comments to your self.

thanks for any help, even if anyone has a good running 2.4L they want to sell.
 
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#4 ·
Pulling the cylinder head to inspect for damage should cost nothing but your time, and the information it will reveal will likely be worth much more than that.

If I recall correctly, four cylinder transfer cases use a 21 spline input while the sixers use a 23 spline, so it's likely that you'll run into a problem there. The good news is you can swap out the input fairly easily if you wish to do so.
 
#8 ·
Oh gotcha, I wasn't thinking of the DOHC engine. Thanks Blaine.

And yep,I just looked it up and the 2003 FSM confirms the 2.4L engine valves can collide if the cams are rotated independently...

DESCRIPTION
The 2.4 Liter (148 cu. in.) in-line four cylinder
engine is a double over head camshaft with hydraulic
lifters and four valve per cylinder design. The engine
is free-wheeling; meaning it has provisions for piston to-
valve clearance. However valve-to-valve interference
can occur, if camshafts are rotated
independently.
 
#11 ·
Thanks for the info guys.

I did replace the timing belt, water pump, timing tensioner and timing idle pulley (all one kit). Had all the timing marks align, yes #1 piston was at TDC. For the cams, had the stamped writing and arrows pointing "up" with the marks aligned but not exact, as per instructions that came with the timing belt.

Get everything together and and took 3 times to get her to start up. she is running rough, at idle she almost wants to die and this may sound funny, the exhaust smells bad. I tried to see if there were any trouble cods but when I do the key thing, it just reads "done"

thoughts?
 
#13 ·
yea, SRTJ that is the thought. I can see the timing maybe being a tooth off it was a chain and dizzy with a toothed gear and all but this is a belt, and a coil pack, no dizzy All timing marks lined up. Kinda almost don't really want to play too much with the cam gears due to the valve interference thing. We also needed to use a 7 ton 3 jaw puller to take off the harmonic balancer, that sucked.

On a side note, I know the PT Cruiser was crappy car but wonder how much it would take to swap in a 2.4L with a turbo from one. Just about the same engine, looks like I could swap some parts from the TJ's to the PT engine. Wonder if I would need to use the PT computer or the TJ's would handle the turbo?

thoughts?
 
#14 ·
The block is cast different but most the internals and head should work. Our 2.4 stared life as a Mitsubishi 420a so most the performance parts will fit. I ran a turbo on mine for a while it handled it but always had issues with one thing or another. Tuning is very limited with the jeep PCM. Parts for this engine are very easy to source. If it were me having done the turbo route I would find the issue and fix it or do a v8 swap.
 
#15 ·
bringing this up again, ok I am picking up a 6 banger engine, auto tranny and xfr case from a 88 Cherokee. My thought is to eventually put the 6 cy in this 03. please don't comment "if you wanted a 6 cyl you should go buy one" whatever. So if I can get the ecu and wiring harness say, from a 2003 Cherokee with the automatic would I rally need to make sure its a 4x4? anything special about that?

Yea, I also know, change the engine mounts, no bid deal, change the tray mount, NBD, drive shafts NBD, anything else. What about the 88 AW4 tranny with the newer wire harness, or is there a year I should stop looking above?

thanks
 
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