V6 engine conversion (2.2 petrol to 3.0 v6 petrol)

[dragunas]

Hello everybody. I was reading this forum a long time, decided to create an account. Sorry for asking questions in first day, but i haven't found any results (or I'm a bad searcher ) about doing an engine swap. I currently have a 2001 406 2.2 petrol, which have developed some problems, which requires some money investment. Some of the problems are: misfire when engine hot (my guess is failing ignition coil, failing 02 sensor) oil leaks from everywhere, timing belt needs a renewal, front brakes are almost dead. So I have considered a whole engine swap idea. I looked over car ads around me, and I could buy a v6 coupe for about 600-800 euros. My question is, what are needed from electric side to do such a swap? All the mechanic changes are quite clear. My car is not multiplexed (round cruise control and radio stalks) so I guess both D8 (es9j4) and D9 (es9j4s) engines are compatible with my electric interface (pre-mux to pre-mux). Is that correct, that to do a v6 swap from electrical side I will need a BSI, ECU and Immo from v6 car? Also I would like to swap some interior bits from v6 to my sedan (speedometer, steering wheel, gear knob), so buying a donor coupe is cheaper. I know that d8 and d9 has diferent interiors. How is this possible, that a d9 has a d8 steering wheel (picture bellow)?

[steve_earwig]

Hi there welcome

No problems asking questions, I think the majority of people turn up here with some sort of problem, it's what car forums are usually about.

I'm afraid you have a bit of a misconception there, your car is multiplexed, all D9's are, it's just in 2001 they got more of it. So, what will you need? Pretty much everything really, it'd be best to get your donor car and swap things one for one. Depending on when your donor car was built there might be some common stuff but it's safer to assume you'll need it all, even if the cars were built days apart.

The only area I can think of going from a 2-door to a 4-door might be getting the BSI to talk to the rear locks, but that's probably the least of your problems. Also, if you stick a V6 out of a D8 there might be some issues with emissions. Plus the authorities in your country might blow a fuse changing the engine size, I think in the UK you'd need an engineer's report but here in Croatia you'd end paying a fortune to get it registered.

[dragunas]

Thanks for reply. Non functional rear locks are no problem, an aftermarket alarm system is installed. I have read somewhere in forums, that you can reprogram current BSI instead of changing it, isn't it? Is this the right way I am thinking? -> After engine have been swaped, V6 engine wiring loom connects to cars existing interior original loom, then I would only change the BSI to V6 one, change the immobiliser and key transponder and it should start away? Registering and MOT difficulties are no problem, there is some way to bypass them

[steve_earwig]

There are no guarantees that the new loom will connect to the existing wiring, changes were made throughout 406 production and it'd be quite easy to find something different, even on cars built days apart. Just don't bin it all until it works.

I think it depends on the BSI, there are 3 levels. In theory you should be able to match it to the new engine ecu but PSA put a lot of work into making sure you have to come to them for a new BSI. Far safer to use the one off the donor car along with it's engine ecu.