Chrysler Repair/engine swapping
My 2.5L first generation Sebring convertible has about 224k miles on it, and I've been thinking about doing an engine swap when it finally croaks. Plus, I've had the transmission recently rebuilt so I think the car can last me several more years.
However, instead of another 2.5 6G73 I was thinking of upgrading to a 3.0L 6G72. I've done a fair amount of research, and I understand that the external dimensions of the two engines are the same, but the difference in displacement comes from cylinder-bore size, making the swap straightforward as far as fitting the engine in the bay.
But I fear certain compatibility issues, like the pairing to the 41TE transmission. Are the differences in HP and torque bad for the gears? Will the bigger engine render the gear ratios less effective? I am also concerned about the PCM compatibility: do you have any ideas of hiccups there?
I think of the 3.0L engine as being marketed mainly in the first half of the 90's and then it was replaced by the 2.5L engine. I had assumed that was an 'improvement' overall because the 2.5 put out about 170 bhp while the 3.0 was only 141 bhp. The 2.5L was replaced around the turn of the century with the 2.7L which had its unique set of cooling system problems early-on.
My initial concerns would be about the wiring incompatibilities to the engine as well as to the pcm which would also need to be changed out to that of a 3.0L I haven't looked into whether the transmission you have will match up to a 3.0L as well.
I guess my initial reaction would be to not change out the engine except if the engine were of a type that was used with that transmission and in that body, and that same time frame and then compare the pcm and all its wiring to see how great are the differences. You may well be getting into a modification whose effort would not be compensated by significant improvement in performance.
I don't see the 3.0L ever used in the Sebring convert so there may be many issues with hooking up the water and fuel supply plumbing to it as well as the exhaust system. And then there are all the issues of pollution control devices that are not set up to be handled by the 3.0L and whether you have to pass a smog test every couple of years in your state. Any unresolved fault code item might be a big headache when that rolls around.
So I would be very careful to undertake this swap.
Please read the PS below.