You are here:

Chrysler Repair/engine swapping

Advertisement


Question
Roland,
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?
Thanks,
James

Answer
Hi James,
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 'advance' overall so I am not familiar with how much more power you would expect out of it compared to the 2.5L. The 2.5L was replaced around the turn of the century with the 2.7L which had its unique set of 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.
Thanks,
Roland

Chrysler Repair

All Answers


Answers by Expert:


Ask Experts

Volunteer


Roland Finston

Expertise

Get a Free Fast answer to your repair question about a Chrysler/Dodge/Plymouth car, minivan, SUV, or truck. Problems with electronically controlled engines and transmissions as well as body wiring problems are my specialty. This free troubleshoot advice forum helps you diagnose faults, minimize repair costs or do-it-yourself.

I answer questions seven days a week and respond to you in about 30 minutes. "Maxed Out" means I am answering another question, briefly unavailable, or asleep overnight, so try again later.

I have do-it-yourself experience (50+ years) and a library of 100 1982-2012 Chrysler factory shop manuals and 20 multi-manual Chrysler Corp. CD's.

I was voted "Top Expert" 2010-2015, here at AllExperts, and have answered 20,000+ questions.

Experience

Five decades as a 'do-it-yourselfer' on domestic and imported cars.

Organizations
Yahoo Autos Group called The Chrysler Lebaron Club (co-moderator)

Education/Credentials
Advanced degrees in Physics/bruised knuckles

Awards and Honors
"Top expert" of 2010, 2011, 2012, 2013, 2014 and 2015 here at Allexperts. Quickest "average response time" at Allexperts (currently no. 1).

©2016 About.com. All rights reserved.