I have a 91 s5 with no motor. But i have a spare s4 na motor. Will it work if i put it in the s5? i have a spare harness and ecu as well. I just want the car to move and run since its only going to be my daily beater.

 

Its a wiring nightmare unless you have run all of the S5 accessories on the S4 block.

You should be able to find a cheap used S5 n/a motor.

 

yes, put it in. youll just need to swap ou tthe front cover and block off the egr passageways.

 

search...

http://rotaryresurrection.com/2ndgen...o_s5_swap.html

 

the car came with no accesories to it.. no ac, alt, powersteering. will i be able to swap th parts over? would it be easier if i switch the harness so that everything connects faster? cause i think the engine harness on this s5 has been spliced and some cut

 

The wiring between the S4 and S5 is totally different, you would have to swap in the s4 harness and then rewire where they connect to get the S5 ECU to work. Its not really worth it when you can find a blown S5 core for dirt cheap and just run those accessories.

 

i see.. but i have a spare s4 ecu

 

Then you will still have to rewire the dash and idiot cluster and fuel pump.

 

dude...did you click the link i posted?

 

yeah i did