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1998 406 Engine swap from 6 to 4

Christo1

New member
Hi, I have a 98, 406 sedan with a V6 XFZ engine coupled to auto box. What I would like to know does anyone know what engine (other than another V6) can be put in this. I realise any swap would also entail associated engine control wiring & ecu. I know it came standard with 3 petrol options, but has anyone retro fitted a 4 in place of the 6. Would appreciate any information on suitable engines. Thanks Chris
 

Demannu

Demannu-facturing!
It is possible - all of the engines in the 406 range are easily interchangeable. I'm currently putting a 2 litre turbo engine in place of a 3 litre V6.

But my question is what do you want to achieve? The V6s are reliable, and no less economical than their 4 cylinder petrol counterparts, but much smoother, torquier and more powerful.
 

68 404

Veni Vidi Posti
The cambox seals leak like a bastard and they eat coil packs for breakfast. Other than that they're ok.
 

Demannu

Demannu-facturing!
The cambox seals leak like a bastard and they eat coil packs for breakfast. Other than that they're ok.
Yes, the cambox leaks are definitely a thing, but not insurmountable with the right products.

And being an early one, it has the single coil pack and wasted spark arrangement, and they seem to last 200,000km comfortably before they give trouble. And the last one I bought was still pretty cheap.

The 4 cylinders are about the same for coil packs.
 

PeterT

1000+ Posts
Yes. What I meant was, the external 8V coil packs don't get toasted like the XU10J4R internal coil packs.
 

STALLED

Sans Pond.
Keep the 6, unless it is seriously broken. The 4 is gutless in comparison.

Also, the cars are cheap enough anyway - I'd consider purchasing a 4cyl one and swapping the good bits from the 6 over. Much of the loom in the D8 cars is plug and play, or easily modified.
 

Christo1

New member
It is possible - all of the engines in the 406 range are easily interchangeable. I'm currently putting a 2 litre turbo engine in place of a 3 litre V6.

But my question is what do you want to achieve? The V6s are reliable, and no less economical than their 4 cylinder petrol counterparts, but much smoother, torquier and more powerful.
It is possible - all of the engines in the 406 range are easily interchangeable. I'm currently putting a 2 litre turbo engine in place of a 3 litre V6.

But my question is what do you want to achieve? The V6s are reliable, and no less economical than their 4 cylinder petrol counterparts, but much smoother, torquier and more powerful.
Thanks for the reply Demannu, The heads, well actually the valves, are shot, the guides & seats are ok, But the reason to swap out is the cost to fix this engine is prohibitive, as I would not just need to do the heads up, it leaked like a sieve and all belts, seals, gaskets and so on would need doing and it's simply not worth it. if the four would swap in without too much grief I would rather do that, the actual body and interior are excellent condition and other mechanicals' are good, I would rather keep it on the road if feasible.
 
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