SRDT

It's not just prechambers, the head itself is also craked. Some say that the tweaks made by PSA on later engines to keep them emission compliant with 90hp also reduced durability. At least it is sure that R&D was much more focused on the next direct injection head for the HDI as emission rules and market trends made direct injection kind of mandatory for new turbo engines.

Not bad for the 406.

It's illegal but you can pass regular inspections as long as it's still a diesel engine and emissions are fine ; and there is no special inspection before registration. The only potential problem is with insurance if someone ends up disabled in a crash. In theory it should be easy to make it legal because Peugeot had a 1.9d 65 hp 205 for export (with EGR) but there is no realistic way to do so anymore.

They got very lucky with the headlight glass, these days with decades old sealant it is not uncommon at all. Some headlights have a metal clip on each side to retain the glass but others don't. Your engine wasn't exactly the right one displacement or period wise but they managed to sort it out. They can now enjoy a well deserved 5 hp and 1 m.kg boost.

It looks good indeed.

You usually borrow or rent one for a day or even half a day. I don't know how expensive it is to do so where you live but cleaning foam can't be cheap either when you have really dirty seats. As for th europ raid nope I'm not in it, I don't even own a 205.

With the seats out on the summer heat you can also use a carpet cleaning machine on them. It works really well but dirty seats can get very wet in the process so it's not good if you left them to dry inside the car.

On 8 bit motronic the checksum is usually with the part number and software revision. They talk a bit about it here: https://www.r3vlimited.com/board/forum/e30-technical-forums/engine-drivetrain/alternative-tuning-w-a-r-megasquirt-etc/375887-documentary-motronic-1-7-diy-reverse-engineering/page6

I had both good bins but not your bad one. I assume that your EPROM looked like a stock one from Bosch? There is some lone data at the very end of your bad bin and that's suspicious.

It was some kind of one off as far as I remember.

It's probably because of the lights on top. Peugeot may have sold a special low trim estate to public services, they had a 205 with better brakes for the Police and a 4 cylinder petrol 604 for the government.

Vallelunga red P3KB / EKB? I know solid red on big cars can be classy (Alfa Romeo...) but on the 406 estate if it's not the right shade it could look more like a former firefighter car:

As long as it's metallic paint why not, if it's non metallic red I'm not so sure.

15" or 16"?

A few years back not everyone was happy with the way the new owner of Politecnic was doing business. I don't know how things stand today.

Not a PDF but you can find it online: https://public.servicebox.peugeot.com/classic/

Your health is more important than a bit of delay on a project car. Take care.

You have one port with no oil so it should be coming from the piston rings or from the valve seals. That plus the broken studs could be a good reason to remove the head.

A common fault with A/C on the 406 is the compressor clutch relay inside the BSI, you're not supposed to change it but it can be done as long as you know where to cut:

The 406 is a nice car. I have read that the XUD11BTE injection pump can be reliable as long as you change the seals when they start to leak.

Sorry MasterYoda but you will find only a few Europeans here and most of the in-depth knowledge is about cars 20-30 years older than your 508.

French parts catalog here: https://public.servicebox.peugeot.com/classic/ Studs here: https://public.servicebox.peugeot.com/classic/AIDE/8505/FB/G3/index.html Wheels and nuts here: https://public.servicebox.peugeot.com/classic/AIDE/8505/FB/G5/index.html Berline means sedan and utilitaire/break means wagon/family, only the sedan has independent rear suspension.

Crankpins are Ø52mm nominal for both engines. Speaking of crank maybe a SAAB crank could be machined to fit the N9T block, the bore spacing seems close. There is also a Ford U.S. engine the 2.3 and 2.5 HSC with a 103,632mm bore spacing.

Is there no way to use Cosworth YB or SAAB H engine rod bearings by machining the rods?

I don't know if you can simply machine the J4R block to J4RS spec, if not you could still create some external plumbing like on the Sierra Cosworth engine. If you don't have a XU10J4R yet then looking for a XU10J4 engine is not a bad idea, the head is the same than the 405 T16 minus the cams and sodium filled valves so you know the design is fine with boost. In fact it is based on the 205 turbo 16 evo head and was also used on the 206 WRC by taking advantage of homologation rules.