Im thinking of buying a BX

Anything about BXs
Mr. Bridger

Im thinking of buying a BX

Post by Mr. Bridger »

What should I be looking for in terms of mechanicals and bodywork?

Post by M »

Have a look elsewhere on the site and see what Tom Shepperd has written about them. I will post a little more when I get time.

Bodywork - Cars with sunroofs seem more prone to rusting than those without. Check the boot floor, door pillars, hinges, check straps, inner wings, rear door slams, sills, rear valance (under bumper if possible).


Mecahnicals - Depending on engine dont worry too much about milage, most of the forum members who have diesel BX's already have done starship milages with little trouble. Petrol engine valve stem seals can harden about 80k or so and make the engine smoky. With all HP cits, make sure the hydraulics do what they are supposed to. Check the system by raising / lowereing a few times and see how quickly it rises and also whether its stiff / jerky.

Check the colour of the LHM - its should be green - any other colour (icluding brown, black or resembling sewage) needs to be thrown out and the system Hydraflushed ( will cost about a tenner to do this). Have a good nose at the HP pipework as pre 1990 cars suffer badly with these coroding - post 1990 cars got plastic coated pipes which lasted a bit longer.

Check the engine for oil leaks (rocker cover, cam end seal and associated pipework going brittle with age). Most are messy, but easy to fix.

The biggy if you have a diesel - cooling - this is responsible for the demise of too many BX's. Look at the coolant fluid - is it green or is it brown ? Brown indicates poor maintainance and silt.

Check the radiator gets hot all over and there are no cold spots - cold spots = blockages = knackered silted up rad = very soon dead BX.
Back flush the rad, fit a cooler temprature sensor switch, retro fit a temprature guage (see DIY tips in main site) and check over all your hoses to make sure they are in good condition. If in doubt renew.
Then refill with deionised water and antifreze. Bleed carefully to avoid air locks.

Start the car from cold and whip the expansion tank cap off - look for bubbling (air bubbles) and look to see if the level rises quickly - this can indicate a faulty head gasket - not in itself terminal, but be aware of what you are taking on and negotiate for it in the price.

Also check for mayo in the oil / water as this too is unhealthy and indicates work to be done.

Check the wheels for wear on the inside edge - with the fronts its likely to be poor tracking or ball joints - the latter are cheap to buy, but a swine to fit. With the rears look for tyres which lean in to the car - a little is OK, but too much / uneven would indicate worn rear arm bearings. Depending on your DIY ability (again - have a good look @ the DIY section for Jons post) could be as little as £50 and some skinned knuckles - or coule be a whole lot more if you let the garage do them.
ABS - if your like me avoid one with ABS otherwise make sure it works (that the light comes on when you first switch on) and that this goes out again within a few seconds. If not it may be that someone has pulled the bulb from the dash to "hide" a fault (usually a sensor- again see DIY tips).

Electrics - make sure everything works! A car this age is bound to have some electrical gremilins. Negotiate in the price if you find anything which doesnt work! Air con - if you find one with air con make sure it blows ice cold.

By no means comprehensive, but its a start. If you do go on to buy a BX, good luck! And welcome to the rubber walpaper club. :)

Post by IvanHo »

How quickly should my back end sink?

Im wondeing if the famous doseur valve, as the car sinks rapidly upon switching off. Its a 1.9 TGD.

There seems to be no problems whilst the engine is runing, and braking, height adjustment are not affected.


Post by IvanHo »

Thank you Jon.

Any recomendations for improving the ride on the BX - dont get me wrong its good, but the existing spheres though functional are about 5 years old. I want to gear the car up for maximum comfort rather than sporty handling.

The pump seems ok and the car will stay up for 3 or 4 days if left in the high position with the engine off - so I dont think I need to put an XM sphere on the front accumilator.
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Post by DLM »

First thing to do is check your spheres against the table in the downloads section on this site, or perhaps against the sphere tables in the suspension section of
The second source contains useful info if you're looking for more of a comfort set-up, as it shows that in general the larger the restrictor hole diameter on the spheres, the softer the ride. This parameter was decreased on the later BXs which are more common nowadays, hence they are slightly less softer-riding than earlier BXs (with the exception of models such as the 17TD and 16v).

A standard TGD should have 55 bar 500cc spheres on the front (rugby-ball shaped), and 40 bar 400cc spheres on the rear (football-shaped). Estates will have 500cc spheres on the rear too.
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Post by tom »