Automobile Repair/Citroen/Citroen XM

This guide aims to tell you how to maintain the Citroen XM.

The XM was supplied with both diesel and petrol engines and manual and automatic transmissions. Make sure you are reading the right section of this guide for your car.

Changing Oil in Auto box (ZF 4HP18)

 * Run engine until warm
 * Jack up car
 * Oil screw is located on side of gearbox (Allen key, size 10)
 * In the next step, removing the filter >> beware of hot oil, use an old glove
 * Locate filter plate (3 bolts)
 * Remove filter plate (take care to preserve magnet piece) and allow oil to drain
 * After oil has drained prize out the filter
 * Clean filter and replace.
 * Clean magnet and replace (in filter plate)
 * Replenish with 3.2 litres (when filter cartridge has been out)
 * Top up oil from dipstick tube (long pipe will be required)
 * Level has to be adjusted according to the 80 degrees Celsius level

Note that due to the design of the gearbox it is not possible to drain all the oil, draining the oil from the filter plate allows five litres to be drained.

Citroen specify Dextron II which is now available as Transmax M, note that this is not the same as Dextron III.

Brakes
The XM has all round disc brakes. The US style handbrake is connected to the front brakes.

Electrical
The XM suffers from low quality electrics, many faults are simply bad or corroded connections. This was vastly improved in the S2 models.

There are also intermittent issues with the under bonnet auxiliary fuse box. Connections for fuses seem to be more liable to corrode or get dirty.

A particular problem with the older XM's is the grounding system used. A terminal block in each front corner of the car under the hood (or bonnet) is bolted to the bodywork and all the ground wires in that area are attached to terminals on the block. There is also a block at the rear and one behind the dashboard but these are less prone to corrosion. The XM has a warning system for blown bulbs and this system regularly flags false alerts due to the poor grounding. Corrosion of these blocks also affects the computer controlling the Hydractive system badly affecting the ride quality.

Assuming the corrosion hasn't progressed so far that replacement of the block is required, disconnecting the individual wires from each terminal, cleaning the terminal and connector and putting it all back together with a coating of petroleum jelly will do wonders for the reliability of the system. Alternatively, the block can be dispensed with altogether and the terminals on the end of each of the wires replaced with eyelets which are then screwed or bolted directly to the bodywork - this is the preferred method since it reduces the possibility of further grounding problems. Later XM's had this done at the factory and didn't suffer from the grounding problems.

Depressurising the hydraulic system
Before working on the hydraulic system, it's a good idea to depressurise the accumulator sphere. This sphere acts as a damper to smooth out pulses from the pump. There is another sphere located lying sideways on the bottom of the engine compartment to provide emergency power for the brakes and steering if the engine stops.

On the regulator block where the sphere screws in (usually low down on the front of the gearbox, in upright position), there is a 12mm bolt with an unusual "stepped" shank. Locate this bolt. With the engine running, set the suspension to low. Let the engine idle for a minute. Switch off the engine, then slacken the 12mm bolt about half a turn - you will hear a loud hissing for a few seconds. The accumulator is now depressurised. Do not remove the bolt completely - there is a ball behind it that will get lost.

If the car is fitted with Hydractive suspension, and this is not working correctly, the centre spheres may still have some pressure in them.

Removing the Suspension spheres
Start the engine and set the car on high. Support the car so that if it does fall, it won't crush you. Loosen the spheres about a quarter of a turn. There are special tools available, which resemble extremely strong oil filter wrenches, or you can make a tool. A length of motorcycle chain welded to the jaws of a pair of locking pliers (Mole grips) will hold the sphere firmly, but the chain might be too thick to fit into tight spaces.

Do not unscrew the sphere any further than a quarter of a turn with pressure applied.

Lower the car, and depressurise the suspension as above. The sphere should come off easily.

Put a bit of LHM round the seal of the new spheres and hand tighten them into position. They should only be put on hand tight.

Rear Spheres
Do not try to loosen the rear spheres with the suspension depressurised. The suspension ram will pop out of its clips and damage the thick pipe, which is expensive and difficult to replace.

Steering
Some left hand drive cars had a DIRAVI full-power steering setup, right hand drive vehicles had a DIRASS power assisted setup.

Lock Issues
The XM seems to have a tendency to have the cylinders in the lock mechanism wear out after extended use, leading to the lock 'spinning' when the key is inserted. This can necessitate replacement of the outer and inner lock cylinder components.

Alternatively, a little bit of home maintenance can help before going the route of replacing the cylinder. T