2000 S70 NA, Swapping in 2.3 T from 2004 C70

[ABV01V0]

I purchased a 2000 S70 NA manual (engine B5244S), very nice shape that looks to have a dropped valve. I have a donor 2004 C70 Automatic (engine B5234T9) purchased at the salvage auction that runs very well, only has 127,000km on it. I have swapped out engines before, but never gone from a non turbo to a turbo. I know there is going to be alot of work, but going to do this with my son and he can have the car once complete (fingers crossed). Since I have the full donor car I would think I need to take the wiring harness out so we can use it to connect all the sensors/parts. I have connected my vida to both and collected the information, want to get started but thought it would be good to get any advice from someone who might have tackled this before. I do have a car lift, and my current plan is to drop the sub frame on both complete, remove engines, do the clutch, PCV if it needs, timing belt was done 40,000 km ago so I'll probably leave that alone. When sub frame and everything is out is when I plan to switch out wiring harness and any other components needed, then reassemble. Thoughts?

[dikidera]

The wiring and the module programming. Are they both H-shaped. I know for My2005+ with the updated CEM it was possible to reconfigure the CEM as it was modular. For the pre-facelift H-shaped modules, I am not sure. Maybe T5Luke knows.

Basically it is wiring and then modules. You will need to be due diligent to compare the wirings of both. For the engine bay you may get away with just using the engine wiring harness, which includes both wires for the TCM and ECM. From then it is important to compare that the new engine harness's signals are correctly wired to the CEM, which is best to simply swap to the S70 as well as ABS and SRS modules. Of course it may still need to be reprogrammed as it will still think it's a C70 and thus may be looking for that switch for the roof. The C70 fuel tank MAY have a PEM module(you will need to consult the wiring) which the NA may not have, which means the fuel pump and PEM module need to be transferred over, the NA will lack the wiring harness for the PEM module which may reside in the trunk in older Volvos or on the tank in an updated version.

The worst case scenario is, and this depends on the wiring, you may have to remove the dashboard and carpets and transplant the entire wiring from the C70 to the S70 up to the fuse box. This may not be required, really depends on what differences the wirings between 2000 and 2004 are.

[scot850]

Are you planning to keep the manual trans or swap over to the auto? Staying with the manual may be easier but there will be some work to do between the back of the engine and the trans if you do.

AS mentioned above I believe there are some wiring changes from the 2003 and 2004 C70's over previous versions. I would be surprised on the PEM being in any P80 chassis, but then this is Volvo...........! If the car has a fuel pump relay in the back half of the fuse box then it does not have a PEM.

I wish you guys luck!

Neil.

[ABV01V0]

Yes we are keeping the Manual, can you expand on the work needed? Ill check the fuse box and see if there is a relay. Thanks Neil

[scot850]

A Volvo friend transplanted a 2005? S60 Turbo engine into a 97 850 AWD (manual only). I'm not sure there are any manual trans in Canada other than the V70R in the P2 chassis so it was likely an auto. Anyway, he got it all to work which included changing it over to a distributor engine. So it can be done.

Changing to an manual from an auto will require removing the torque convertor and flex plate and then installing the flywheel and clutch from a manual. I am not sure on these engines if there is a pilot bearing built into the rear of the crankshaft as I have not worked on a manual trans 5 cylinder. So that will have to be figured out.

As for the electrical stuff, I would expect most of it to be similar but there will be differences for the things like the shift interlock from an auto trans to work out and disable, you won't have a TCU in your car being a manual.

There will be differences in the turbo wiring harness over the NA with different sensors. Even the muffler system may be different but again I have had not tried comparing them.

If you guys need another set of eyes, as you are in Calgary, PM me here on MVS and I can come have a look and see if I can add to the knowledge pool on this challenge!!

Neil.

[dikidera]

The good thing is, he has everything, all the sensors and parts he will ever need.

[falcor75]

The turbo engine may want to see the key + decoder and instrumentcluster from the car it came from in the new car as those probably are connected and paired together. Just a heads up to be aware of.