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Chrysler 300, 300C & 300C SRT-8The flagship of the Chrysler lineup offers the driver every bit of class of any European luxury sedan, combined with the availability of the Hemi, the engine which dominated the American Muscle Car Era
Hello All ,
I have a 2008 300LX with the 2.7. The engine that cracked a rod 20K miles ago, replaced rod, crank, pistons, rings water and oil pumps. Have been using synthetic 5-20 ever since. A tick-tick became a very loud knock after full throttle accel to merge into traffic, nursed it back about 1 mile to get back home, made it, and shut down. Oil level right on full level, no water in oil, pulled oil pan and crank is broken right after the first two cylinders.
Question is, is it feasible to replace the 2.7 with a 3.5 or do I have to either repair this 2.7 turd again or junk the car? Bought the car with 136K miles on it and the engine was rebuilt 1K miles after that. Any help will be appreciated.
Many thanks,
Ed
Don't do it (replace the 2.7 with .3.5)!! Engine swaps on modern vehicles with multiple computers, sensors, connectors,software, etc are a major undertaking.
I would repair or replace that 2.7 no matter how fed up with it you are.. There must be suitable 2.7s on the used market.
Hello All ,
I have a 2008 300LX with the 2.7. The engine that cracked a rod 20K miles ago, replaced rod, crank, pistons, rings water and oil pumps. Have been using synthetic 5-20 ever since. A tick-tick became a very loud knock after full throttle accel to merge into traffic, nursed it back about 1 mile to get back home, made it, and shut down. Oil level right on full level, no water in oil, pulled oil pan and crank is broken right after the first two cylinders.
Question is, is it feasible to replace the 2.7 with a 3.5 or do I have to either repair this 2.7 turd again or junk the car? Bought the car with 136K miles on it and the engine was rebuilt 1K miles after that. Any help will be appreciated.
Many thanks,
Ed
Yes it is possible, and it actually is a pretty straight forward swap. The 2.7 and 3.5 use the same PCM.
I'm currently doing the same swap in my Magnum right now. Also, the 2.7 has better gearing, so putting the 3.5L in will benefit from it.
You will need a long block though, because the air intake etc do not swap over.
The only thing that may be an issue (and I haven't verified it yet) is you may need a 3.5L engine wiring harness. I have read both that you need one, and that the 2.7 harness will work.
If you do need the engine harness just make sure you get the one that also matches your transmission. That may be why there are conflicting stories, possibly someone tried a engine harness from a car with a 4LQE transmission on a NAG1 transmission.
Hope that helps.
This is my current 3.5L build. Almost finished. This is my current 3.5L Build
01-20-2021, 07:25 PM
Possible to replace 2.7 with 2.5 or am I nuts?
