Stratusphere

Swapping a 3.0L Engine into the 2.5L V6 Dodge Stratus, Chrysler Cirrus, or Chrysler Sebring Convertible

There is an ongoing thread about this engine swap, which can be found HERE .

STEP 1
First you need to find a motor donor car. The following are suitable:

  • 1999-2000 Mitsubishi Galant ES
  • 2000-2005 Mitsubishi Eclipse GT or GTS
  • 2001-2005 Dodge Stratus Coupe
  • 2001-2004 Chrysler Sebring coupe

STEP 2
Refer to your Chiltons, Haynes, or factory service manual on how to remove your existing 2.5 V6 engine. You can either take the transmission out or leave it in. If you opt to leave the transmission in please be careful when installing the 3.0 engine, so that you do not damage the flexplate!!! Now would be a good time to consider using a rebuilt or performance-built transmission.

STEP 3
It will be ideal to have each engine on a stand for this part. Now what you need to do is strip down your 3.0L engine. The only things that you will need on the 3.0 are:

  • the block and heads should be kept intact, including cams
  • the front valve cover
  • cam gears
  • water pump
  • timing belt (NOTE: if your donor motor has over 40000 miles on it, you might as well replace the timing belt now. You will never have an easier time.)
Optionally, you may also want to remove and keep the following items:
  • Fuel injectors with both parts of the harness and clips as well as the lower intake manifold (you will need to cut the harness to your 19lb injectors to splice the 21lb injectors in place.)
  • To remain "emissions legal," you will need to tap the side of the head to run your EGR valve opposite of the pulleys about 1.5 inches below the valve cover. There are exhaust ports and the one on the far right is the one you will need to tap into. Look at the 2.5 engine - on the side of the motor you should see two threaded bolt holes where the EGR valve is. If you remove the EGR valve off of the 2.5 you can use the 2 bolts and the gasket as a template and just simply use a drill and drill right through.
All other parts will not be used. If you had a complete motor, you should have pulled off the oil pan, rear valve cover, alternator, power steering pump, distributor, cap and rotor, A/C pump, exhaust mannifolds, starter, oil filter adapter, plugs and wires, water x-pipe, intake manifold and throttle body assembly.

On the top of the 3.0 there is a crank sensor with a wire coming off of it. Just simply snip the wire and cap it off or tie it off as the 2.5 computer will not use this.

STEP 4
Time to strip down that 2.5 and transfer everything over.

  • Start by removing the entire harness and intake manifold and set them to the side. They will go back on last.
  • Remove the cap, rotor, and distributor. Inspect them, replace as needed, and install the on the 3.0 engine.
  • Remove the exhaust manifolds and set them aside.
  • Remove the starter and install it on the 3.0 engine.
  • Remove the oil filter and adapter and install the adapter on the 3.0 engine. Install a new oil filter onto the adapter.
  • Remove the rear valve cover and install it on the 3.0 engine.
  • Remove the crank pulley and install it on the 3.0 engine, making sure it is torqued on correctly.
  • Remove the power steering pump and bracket and install it on the 3.0 engine.
  • Remove the alternator and bracket and install the bracket on the 3.0 engine. Inspect the alternator - now woul dbe a good time to replace it if needed.
  • Remove the oil pan and install it on the 3.0 engine. When installing it, two of the holes on the transmission side (the two that are either side of the rear main seal) will not line up correctly. You can either RTV it or simply drill new holes. It is also a good idea to replace the rear main seal on the 3.0 while you are in there.
  • Install the exhaust manifolds onto the 3.0 engine using new gaskets. If you choose to do so, this is also time to install the EGR valve and tube.
  • Decide which injectors to use. No matter which injectors you choose, use the fuel rail from the 2.5 engine. Install the lower manifold from the engine you got the injectors from - make sure to use new gaskets.
  • You can opt not to use the upper intake manifold brackets, as they will not fit on the 3.0 engine without modification - you will need to grind them down or plasma cut. Some that have done this swap hae opted to not install these brackets at all.
  • Remove the water x-pipe and install it on the 3.0 engine.
  • Install a new set of plugs and wires on the 3.0 engine.
  • Remove the wiring harnesses and install on the 3.0 engine.
With everything put together, refer back to your service manuals and put the 3.0 engine into the car.

STEP 5

  • Install the upper intake manifold using a new gasket.
  • Replace your throttle body gasket.
  • Install your alternator.
  • Plug in the rest of the wiring harness plugs. (The plugs down by the transmission are a pain if you left the transmission in.)
  • Install the power steering belt and serpentine belt
  • VERY IMPORTANT! Fill the OIL, COOLANT and TRANSMISSION FLUID!

Fire it up!

Drive around for at least 500 miles before getting on it - ideally break-in should be around 2000 miles to give the computer time to adjust and make sure you have everything going right.

THE ORIGINAL AUTHORS OF THIS ARTICLE, AS WELL AS STRATUSPHERE, ASSUME NO RESPONSIBILITY SHOULD PROBLEMS OR DAMAGE OCCUR WHEN USING THESE INSTRUCTIONS. REFER TO YOUR LOCAL LAWS AND REGULATIONS ON MOTOR SWAPS AND GET PLENTY OF ADVICE BEFORE BEGINNING SUCH A PROJECT.

There is an ongoing thread about this engine swap, which can be found HERE .