Maintenance done on my CXes

Oil & Filter change

Consider this a 'point and pay' job. The filter on the GTi models is almost impossible to reach, and as there are companies like Kwik Fit that charge based on the amount of oil needed it is always nice to have it done. Join the mechanic underneath the car when it's on the lift for a quick inspection of rust and condition of various hydraulic lines.
Changing the transmission oil (Dex II in case of an automatic transmission) is easy. Put the car on high and undo the two bleeding screws. 2,5 liter of used fluid will pour out. (By the way: the total capacity is around 6 liters, the system can be drained almost totally by draining at the oil cooler next to the radiator)
Preferably do this with a hot engine as the oil will flow out way easier. Filling is time consuming: the location of the filling hole necessitates use of a funnel and some tubing. And the new oil is cold and viscous of course...

Oil pressure sender replacement

On a nice sunny day the oil pressure light came on when idling at a parking place after a long drive on the german autobahn. It went off again after accellerating, so no problem at all. Then it started to come on more often, and I took a closer look at what was happening. Tiny bit of oil dripping off the oil pressure switch. It being a saturday afternoon (garages closed until Monday morning), I thought I might as well get a switch after the weekend.
Wg! Driving to work in the very same evening the dripping became running and I lost a liter of oil in 20 km. So roadservice was called before driving back home. Not having a bolt of the right size at hand to screw in the block the guy filled the little hole in the sender with solder. This fix held until the replacement arrived the next Wednesday.
Lesson: once the oil pressure switch starts dying, it will become a big problem fast, so put a correctlty sized bolt in your glove compartment. Order one at the first sign of it being shot. Further not a problematic repair at all:
The oil pressure sender is located. at the backside of the engine, right of the oil filter. It can easily be taken out. Don't forget the copper gasket when fitting the new sender.

Flywheel Sensors

A well known little fault in the EFI models. One (> '87 MY) or two sensors (before then) pick up flywheel speed and position. Once in a while they break internally and this starts showing when they are warm. When the sensor breaks in a one-sensor model the engine will cut out. If the sensor is bad but not completely broken the engine will run again after cooling of the sensor. On the two sensor model there are two possibilities:


underbonnet view of a 25 injection engine
1: Flywheel speed sensor fails: in this case the engine keeps running, but the rev counter stops. Very strange to see it fall down to 0/min when you are doing 150 on the autobahn and you assume the engine is running...
Still, for the ignition computer to keep timing correctly this sensor is needed, so when the rev counter starts behaving strange and the engine still seems to work fine: replace the faulty sensor.
2: Flywheel position sensor fails: in this case the engine will cut out as the fuel pump will not be operated anymore and timing of fuel injection becomes impossible. Again, a faulty sensor becomes visible at first when the engine gets hot. So you are in the sun in a trafficjam at a very busy place and ... oops, engine cuts out just as the traffic starts to move. Open hood, and after exercising a bit of patience the engine runs again. To avoid forced cooling-down breaks replacing the sensor will help...
So now how to recognise a faulty sensor? Easy: connect to a multimeter and put in water (pan or boiler). Connections not immersed of course. Now read the resistance (should be around 70 ohm) and start heating the water. Resistance should remain constant until water boils. If it starts rising the sensor is shot. Replacing with a new one is a two-minute job. Just a pity the sensors are so expensive. Is that mr. Bosch a millionare already?

Fixing bad running

One day the engine suddenly lost all power, coming off the highway. Started suspecting the gearbox but made it home. Inspection (clamping off fuel lines to the injectors) learned the engine was running on two cylinders only. Wiggled some wires to one of the coils and it ran perfectly again. Problem solved. Or not ?...
The next day after driving half an hour and having parked the engine started but refused to run on four cylinders. Tried a spare coil I had lying around and it ran fine. So it was not the wiring but the coil... However, the spare coil had ended up in the basement because of showing the same symptoms. So again after some time driving the problem showed up again. Solution is easy: replace with a spare coil.
These coils seem to die regularly. A bad capacitor (as was found on my car) puts more load on the coils and catalyse their demise. So make sure the capacitrs are connected well and when the engine starts running badly and the problem is not the air feed hose (see below) check the coils. Difference in symptoms: with a bad coil there is a rough idle and no power. With a bad air feed hose the idle is rough, but at higher revs the engine is fine.

Air feed hose

Another well known, and easily solved, problem on the EFI models.
A fuel injected engine lacks a carburettor. Therefore, the mixture is not made up by sucking petrol into flowing air using a venturi effect, but by injecting a metered amount of petrol into a measured flow of air. The injection computer calculates the needed amount of petrol from the measured airflow, which itself is determined by the throttle position.
To obtain the right fuel:air ratio it is essential that the right amount of air is measured.
If a leak occurs in a hose between air flow meter and inlet valve more air will be present in the final air/petrol mixture than intended. In this case the engine is running lean.
Not too bad when revs are higher, but the cause of rough idling or cutting out when idling or slowly cruising. When these symptoms occur it is good to check the concertina hose (see picture) for cracks. It is difficult to repair cracks in the hose, and much easier to install a new or second hand replacement part. Other leaks may occur in the crankcase breather hose or the cold start bypass hose.
If the problems arise with idling when the engine is cold the problem is most likely the additional air valve (located at the back of the engine next to the oil filter) is not opening sufficiently when cold. This valve can be easily replaced as well.

Replacing Ft Brakes

At a certain moment the disks will be too thin for  proper adjustment of the handbrakes. Which, in itself, is quite an easy job. At this point, you notice the disk thickness is already 2 mm below specs... Time for disk replacement (and so replace pads as well, but that's easy). This too is quite a straightforward job. Take off wheel. Take out brake pads. Take off handbrake mechanism and remove handbrake pads. You have now reached the stage of the left picture below. Oops. Did I forget to write depressurise system? Then do it NOW. Now remove bolts holding the caliper and take off the outer half. Even after depressurizing, a bit of LHM leakage will occur. Have a container ready to collect spilling fluid (second picture).


(pictures by )
Now remove the crosshead screw holding the disk to the hub. Drilling it out may be necessary. Take off old disk, clean and grease hub. Clean new disk and put it on. Fit crosshead screw. Put caliper back together using new seals when the old ones look worn. Put new pads in. Handbrake pads too. Now you have reached the situation of the third picture. Do the same on the other side and adjust handbrake (that's easy now). Start engine and pressurise system. Have an assistent press the brake pedal while bleeding the brake calipers. Don't forget to connect the pad wear indicator wires (right picture). Now put the wheel back on and lower car before driving away ;-)

Replacing a lower balljoint

Every year the technical inspection has to be passed. Apart from futile check-list items like working lights (of course they always work) there are also some serious items to be checked.
Like the balljoints in the ft wheel setup. When a lower balljoint (or its dustcover) is damaged this is an 'on the driveway' job. Start by putting the car on high, supporting it by axle stand and lowering the suspension. Remove the roadwheel. Undo the bolt holding the balljoint in the suspension arm.
Now don't remove the bolt completely, it will still be necessary...
Now remove the two 13 mm bolts (they are secured by a locking tab) holding the balljoint in the ftwheel bearing housing. Now the balljoint has to come out. Support the hub on a jack and lift it up a bit. Some blows with a hammer will first release the tapered end from the arm and then, as the arm rests on the bolt, remove the balljoint from the ft wheel bearing housing. Now tap the balljoint into the arm again and remove the bolt (it may be necessary to just saw through the thread). Fitting is very easy: put the balljoint back in the ft wheel bearing housing, lower the jack and fit the tapered end as well. Now put the jack under the lower suspension arm and raise the setup. The balljoint will now be pressed in place by the weight of the car. Tigthen the bolts and nut, secure the locking tabs and lower the jack. Ready!

Replacing a door hinge

As all CX owners know the door mechanism starts clicking after some use. Of course this clicking is the most audible on the drivers door. Reason is the wearing of the U-shaped pin connecting door and hinge spring. This is the time to put some extra grease on the spring and/or fix the U-pin and its closing plate.
Tips for this can be found on Pontus' website.
In the case of my CX, things had gotten worse, as the constant pressure of the clicks on the door hinges, combined with some corrosion and wear one day resulted in the breaking of the hinge pin. That of course does not need to be a problem: extract its remains from the hinge and put a new pin in. I've seen more expensive parts on the CX.
Here the problem started: the middle piece of the pin had corroded solid in the part of the hinge connected to the door. It even could not be drilled out. So the hinge had to be replaced. I still don't understand why Citroën did not bolt this hinge in place.
Citroën used spot-welding to fasten the hinge to the door so it turned out to be possible to drill out the spot welds and take the hinge off. A replacement hinge was obtained from Citroville using the same procedure (thick and very stg steel! Use cutting oil!). Good enough, all spot welds are in the same place, so using 4 bolts through the spot-weld holes the new hinge was simply bolted in place. And finally the pin could be replaced...


the door taken out and here's how the hinge is bolted in place on the flange of the door

Worn interior reupholstered

Two jobs had to be done: fixing a little hole in the drivers seat and fixing the hanging rooflining. The first problem is a specialist job when it has to be done invisibly, keeping the original stitching pattern as it was and inserting the new cloth seemless and invisible into the old cloth.
Fixing the rooflining is an easy do-it-yourself job, also described in the 'interior' pages.

Solving overheating problems

One (warm summer) day a friend borrowed the car and quickly after driving away alled me: "The engine runs hot !". When arriving at the car everything appeared normal: coolant present, enough oil, obviously nothing wg. Except for two non-working fans in ft of the radiator. So I decided that had to be the case. Some fumbling around under the relays soon made them both come on. Ah, the (in)famous Citroën wiring. So cleaned the contacts on the relays and stopped worrying.
Next time the solution was not that easy. Again the fans did not work. Removing the connector from the thermoswitch on the radiator and short circuiting the contacts with some wire gave a hint: everything worked correctly now. So replace thermoswitch. Since then I had no problems anymore.
Still the fan wiring is pe to problems as many CXers will confirm.
The correct functioning on series 2 models is as follows:

Faults can occur at the folloqing places:
In general, overheating of the engine is almost always related to the wiring of the fans. Do check the coolant level first though! (Take care when the coolant is still hot!). Solving problems is therefore relatively easy.
In some cases, especially after changing the coolant, the problem may be air trapped in the system, as the bleed screws are not in the places most suitable for the purpose. Bleed screws are located: (i) on top of the radiator, (ii) on top of the water pump and (iii) on the cylinder head, hidden behind the cyl. 1. inlet manifold. When the car is running hot after filling and bleeding just bleed again...

Headlights

Shortly after being hit by a car backing up I installed a new headlight. Then one day (or actually night) I noticed the adjustment of the main beam was off. Well, no problem of course, as both horizontal and vertical adjustment of this small beam are done by one 8 mm bolt. However, the adjustment was impossible, as it turned out the little reflector was just hanging loose in the sealed headlight unit. The little plastic clip that holds it to the adjuster had broken.
As this was the second time I had to do this repair (the previous light also suffered from this) I thought it was time for a description.
Basically it is dead easy. Start with taking the light unit out of the car and then removing the glass (carefully!). Clean the surfaces of glass and housing and remove the old silicone kit.
Remember never to touch the silvering as it is easily damaged !
Now remove the main beam mirror (prying a bit with a small screwdriver will help). You will end up like in the photograph below.


It is easy to see what went wg: the brittle clip holding the plastic pivot piece has broken and no longer attaches to the mirror. It can easily be restored: any good 2-component glue will fix this problem forever. Glue both pieces back where they belong (almost certainly the upper clip will have broken when prying the mirror out), as seen in the second picture.
Put the mirror back in the light unit. Seal the unit again using a silicone or comparable sealing kit.
Now mount the unit again and adjust the beam (at night, using a wall and a centimeter, with the engine running to have the car leveled). The final result will be astonishing!

Repairing dashboard electics

This operation may be necessary again, sooner or later. For instance, when everything starts blinking with the indicator lights... However, taking the dashboard apart is easier as it looks. Start by opening the console of course, remove the two screws that hold the instrument cluster. Mark all connectors and take them off the instrument cluster, then tilt this unit upwards. It is still held by the speedo cable. To undo the speedo cable, a bit of pressing with two screwdrivers may be needed; it clips ìn the speedo connection.
We now have somethink looking like this (below,left). This is also the time to fix all those burnt-out bulbs! They are standard 1.2 W bulbs clipped into plastic fittings.


The instrument cluster can be taken apart by removing the little plastic plugs that hold the printed wiring in place (middle) and then removing the black back of the cluster (right). Now you will find the PCB that controls the oil level meter (red arrow) and the back of the tacho, held in place by two screws (yellow arrows)
Problems can occur when the soldering points have chafed through the isolation of the plastic printed circuit. Taking everything apart and isolating the printed circuit (using scotchtape) will help. To remove the white clips that hold the circuits: just lever them out with a screwdriver. Behind the first layer, the printed circuit boards for the oil level indication and (behind that) the revcounter are found. Never needed to fix those. After redoing all suspect soldering and after making sure that everything that should be isolated is isolated, put everything back were it came from. It only fits one way ;-)

Solving the interior fuel smell problem

After driving around for a while, just after buying the car, I noticed there was an occasional smell of gas in the car now and then. I wasn't alarmed too much, but something else was annoying as well: below the gas filler opening there always seemed to be small gas leakage traces on the body, damaging the paint and making the trim strip come off. So that had to be fixed.
First a new cap for the filler opening was bought, but to no avail. The smell and the gas traces stayed as they were.
So there had to be a leak somewhere... let's start searching...
The car was put on high, the wheel well cleaned (but way insufficiently) and the toolbox brought. After undoing the bolts around the filler opening and undoing the hose to the gas tank (only do this with an almost empty gas tank) the whole setup could be lowered.
This part is hardly described in Haynes, so the whole setup of tubing that came down was a bit of a surprise. Next to the big hose to the tank two small hoses go up to ventilate the tank when filling the tank. Then another line connects to a bottle with a ball-valve, clamped high up in the wheel-well.
This serves for ventilation of the tank when the cap is closed. Thus the cap should seal the opening, something already suspected looking at the rubber insert in the cap.
Getting rid of fuel smells means all ventilation should go through this device. So putting everything back in fasten the filleropening setup to the body (with the rubber gasket in between), and put the mounting plate for the central locking device more on the inside (to the boot). Further make sure the ventilation hoses are clean. Still, having done all this, fuel smell may return. In that case it will turn out (in my case by accidentaly looking at a CX at a breakers yard) that a ring shaped metal insert in the filler opening is missing. It is essential: this is what the rubber insert of the filler cap is sealing against.
When the ring is missing: find one. If it seems to be a loose fit: glue it in place. Having done all this the car should remain free of fuel smells, and no leaking will occur anymore on your valuable paint. In my case, the rear quarter had to be repainted because of paint damage by excess fuel dissolving the top layer.
So after finally inserting that metal ring, two problems were solved at once...

Fixing the 'clicking' ventilation mechanism

One day switching the 'windshield heating' function off a loud clicking noise started to sound from within the lower right side of the dash. Having heard of this problem from others the problem was easy to solve: culprit is the motor driving a little gear that moves a flap in the heater box: the cogwheel can loose good contact with the gear.
Solution is to take out the glove box (undo two screws in the glovebox and two nuts at its sides. Proceed with taking the light out and disconnect it and then pull glovebox out), and remove the upholstering from the right side of the center console (just undo four screws).
The car will now look as shown:


demister flap drive, indicated by arrow

The motor driving the gear is mounted by two screws. A piece of plstic a bit more to the ft of the car is the third supporting point. Adding two layers of band-aid on the motor at the place where it touches the support reestablishes firm contact between motor and gear and all works fine again. One more easy fix!

Fixing an electrical failure

One day the engine stopped and refused to start again. Thus roadservice was called. According to them, the cylinder head might have been damaged. The car was brought to a nearby Citroen dealership and diagnosed. The result of the compression test is shown below...
Clearly, nothing was wg with the engine mechanically, but what was the case then? There was ignition, even though the sparks were weak. Replacing spark plugs, spark plug cables, coils and the complete ignition ECU could not solve the problem thus it had to be found somewhere else.
Next to check is the fuel, but that seemed to be dosed. However, too much fuel is a problem as well...
The injectors were open continuously drowning the engine. With a big hose clamp around the fuel line it would run 'fine', but this was not as it should be. Thus a problem was expected with the injection ECU, found in the ft passenger footwell, under the glove compartment (picture left)

However, the computer was OK (another GTi Auto ran fine with it) and thus it had to be the wiring. Well, that is obvious on a CX... apart from rust all other problems originate from wiring :-(
Thus the cabletree was removed from the car (which is a very straightforward job: just unclip all connectors and free the looms from all clips and tie-wraps holding it. Then remove the glove box and gain access to the injection computer in the passenger footwell. Disconnect it and push the big connector through its opening in the firewall.) The complete wiring loom was taken inside for testing (right picture). The corresponding wiring scheme is given on the left (click on it for an enlargement, over 300 kb of jpeg...). It turned out that there was a short circuit on the little piece of wiring connecting the injectors, the auxiliary air valve and the engine temp. sensor to the computer. Replacing the wiring loom should result in a working car...
However, it turned out that there were several different wiring looms available for this type and build year of car and that of course the first wiring loom I fitted was the wg one... So with help from a friend finally the right wiring loom was found and installed and after a month of looking at a stranded car the CX was on the road again...

view of a 25 injection engine and its injection wiring loom

Fixing the air horn

Here just a picture of the interior of the compressor that supplies air to the horns. The compressor works because the soft flaps are sealing chambers of air by being pressed to the main air chamber wall by centrifugal force.
If the little flaps get sticky, the action is inefficient and not enough pressure generated to sound the horn. Remedy: take apart and clean all parts very well. Then apply silicone spray and put the pump together again. Another easy repair.

Replacing the starter motor

On the day I picked up my newly acquired Prestige of course I needed to make a stop to get gas. After filling up, the starter motor refused to work. I called roadservice, but before they arrived it came back to life again and started the engine. So I could cancel the assistance. However, it meant the starter motor had gone bad and needed replacement.
Replacing the starter motor turned out to be a bit of a nasty job on the 25 IE engine with autobox, as all the available space down there is crammed with goodies like a transmission oil cooler, the bigger automatic gearbox, a hydraulic pump and last but not least the airconditioning. The starter motor is held in by three bolts. The lower two are easy. Essential however is to have a good tool (socket, ratchet with flexible coupling and extension) to remove the top bolt holding the starter motor in. You will find everything is in the way for the tools and who wants to dismantle any hydraulic piping or remove the alternator? For the rest it is an easy unbolt/bolt in job.
Don't forget to put the car on axle stands in its high position first by the way: access from below is essential and without starter motor the car can not be lifted...
Before, give the heat shield a nice treatment with Hammerite and make sure you fit it correctly as the thick cable feeding the starter motor sure doesn't like the exhaust heat!

More to come:

My newly acquired Prestige turned out to be far from flawless... Many fixes are already done and many more will be necessary. Descriptions are to appear from: and unfortunately much, much more...