What would it take, electronically, to swap a 2004 4.2 E+T into a 2005 xk8?
Is it feasible?
or should I have my trans rebuilt and struggle with a front seal replacement?
I can purchase engine/ trans combo for less than trans rebuild.
I would handle the labor (diy).
wj

 

Wish I was closer, what are you waiting for.
Here's hoping you got a good one or should I say both.
Biggest problem I see is the wire connectors, they have been subject to a lot of heat, car and Texas.
Keep all the sensors from yours and don't get in a hurry.

 

I don't think they changed much going from 2004-2005 so you should be good but someone with more experience will know. If they did change stuff it might be a lot easier to just rebuild instead. If you swap it though you are working with an engine and transmition that might also have problems.

 

so do I
wj

 

I can actually drive the car with engine /trans at the moment. Check compression and listen. If the mileage is less and every thing sounds good...I think it is 'almost' a no brainer. I was worried about the trans valvebody and other things electronically related.
(hopefully)

wj

 

You mean you can actually drive the donor car at the moment? In that case it seems a no-brainer assuming you can obtain the entire donor car - any missing electronics you will have in the donor.

Obvs question tho - whats wrong with the donor, why not just drive that instead?

 

AFAIK the engine and trans are identical. Just transplant the long block and trans. Put all the 2005 stuff that may be different onto the 2004 engine.

But, if you are capable of doing all that, why is replacing the trans front seal so difficult?

 

engine front seal+ trans seal+trans was acting funny going into 6th+130k miles!
WJ

 

Ahh, engine front seal. Got it.

During your last trans service, did you replace the mechatronics sleeves? They get hard after a decade, or so, and should be replaced. Several places offer them in their trans service kit. If they get hard and leak you'll get all sorts of oddball shifting problems.