2003 Buick Century 3100 into 98 Grand Am 3100

[98GrandAmSE]

The motor in my 98 Grand Am SE, 3100 is bad. I am picking up a 3100 from a 2003 buick centruy that has 22k on it. From what I have read the engines are the same with differences in the sensors, and TB? Im new to this whole 3100 motor thing. Can anyone confirm that the motor is a direct drop in with the change of some sensors, fuel injectors, and wiring?

Any help, or links I may have missed during my search would be greatly appreciated

Thanks

[korbendallas68]

You shouldn't need to change any of the sensors, can if you want to, but I believe it's not a problem. The one though I'm not sure about thought is the coolant temp sensor under the TB.

The TB linkage (shaft) will have to swapped out. The fuel injectors will also be changed. The EGR will plug right in also.

[Guest]

Agreed the sensors shouldn't need to be changed. But as mentioned check the CTS, some were two wire, some were 3 wire, use the one that plugs into your car.

Swap the injectors. TB linkage, just like the CTS, check it to verify that they are different.

[98GrandAmSE]

The exhaust manifolds are different on the 2003 motor, than whats on the 98 motor. The 2003 manifolds have the outlet in the middle of the rear bank manifold. The 98 has it on the side. There will be no restrictions on the flow or other problems if I put the 98 manifolds on the 03 motor? Or will the down pipe from the 03 century work in a 98 grandam?

Thanks for the help

[korbendallas68]

Use the Grand Am's manifold. Save your self the money and the headache. There really is no gain from using the newer one, might actually hurt performance.

[Guest]

Use the Grand Am's manifold. Save your self the money and the headache. There really is no gain from using the newer one, might actually hurt performance.

There will be people that will debate the gain or lose from using the center exit manifold.

But I do agree, for a stock to stock swap, just use the manifold from your car.

[98GrandAmSE]

Alright sounds good. Ive never worked on a grand am that why I have all the questions. This car has a bad motor and was given to me free, so I figured I would swap a low mileage newer 3100 into it. What type of gas milage does a 98 SE get?

Also is there a write up anywhere on this board on how to remove a 3100 from a grand am. Im going to purshace a chiltons manual for some help, but sometimes boards like this have write up on how to.

Thanks for all the help guys