Randombloke

Thanks Coastline, will find someone with a Lexia.

I have been getting intermittent Auto Parking Brake Off warnings on the dash. When this happens, the system also gives me a "Parking Brake Faulty" via the warning system, the parking brake still works, but the auto hill start no longer works, and I suspect the driving away to provoke the handbrake to go off will no longer work either. There are no other problems, and the ASR/ESP warning is not on, so I can assume all the clever sensors working with that are fine. Hard to get it looked as as the warning can appear whilst driving, and also disappear whilst driving too. The handbrake works as expected otherwise. Any clues?

Please can you clarify if the boot fails to open on the button on the boot itself, or on the button for the boot on the remote, or both. Sometimes with PSA Peugeot Citroen cars the wires from the boot button on the boot itself get fractured or broken where they pass from the tailgate into the car, but the button on the key fob will still work.

You can always eliminate the EGR valve by buying a blanking plate and temporarily blanking it off; if the problem is solved then the EGR valve is at fault. About £3 on eBay.

There will be a second thermostat that turns the radiator fan on. Normally it should click on when the temperature reaches a point specified in the Haynes manual or similar. If you haven't got one then worth Googling for images or diagrams of your engine.

Europarts. Most of them are not PSA parts but are made by another company, Delphi. You'll find them in Engine Management Switches. Enter your reg first.

To eliminate the EGR from the system, buy the £2.50 blanking plate and install it, if there is a lot more power or better fuel economy that's your answer. My own view is that the Mk 1 sometimes had slightly binding brakes, worth having a look to see if the front wheels are free as the parking brake works on them. A quick clean there can often be worth 2-3 mpg.

Mine is at the very top, on the drivers side, up against the wiper/light sensors. I've had no problems with it there.

Echappement is the exhaust, FAP = DPF. Controle Eolys will be checking of fluid of the same name. Huile is oil. Go here: http://www.wordreference.com/

The car has gone into "Eco" mode. This is reset by starting the engine. When you try to close the boot with the button and it refuses does it beep twice? If it does this would confirm "Eco" mode to protect the battery. When you turn on the igntion before starting you'll get Eco mode confirmed on the dash.

UV style dye in the oil then use a fluorescent light to examine the engine?

The cables do stretch. Seen this fault on a few cars. Easiest to put a brick on the accelerator engine off and check that it is hitting the end stop under the bonnet. Not easy to adjust without removing stuff.

The mic is in the roof just behind the three courtesy lights IIRC.

I suffered a similar lack of power and poor economy but not a flat spot. It was the EGR valve, which has now been replaced. Yours may also be the EGR valve, and to test out this theory you could buy a £2.50 blanking plate on eBay, install it and see if this fixes the problem.

For the little it will cost, have you considered replacing the battery and eliminating this from the list of possible faults?

It's a bad idea to drive any hydraulic Citroen when it's down on the bump stops. When you unlock the car or start the engine does the electric pump for the suspension hydraulics run? If not, the has pump croaked, the ECU that controls it is faulty or the pump fuse has blown, as a few examples of the problem. Is there fluid in the suspension reservoir? Any signs of suspension leaks? The fluid is LDS and should be orange, can you see any outside the reservoir? If there is no fluid in the reservoir or it has leaked, this would also give you grief.

Kumho Ecsta KU31, but the prices appear to have gone up. Black Circles no longer list it.

I've had this on the passenger side, fixed under guarantee, garage claimed that the motor that drives the hot/cold mixer flap had died. Common problem on Mk1/Mk2 but I was not aware of it on the Mk3. Very costly to fix and was the only thing covered by the otherwise totally useless Network Q guarantee. Symptoms are that you can't alter the temperature by turning the dial. Outlets blow air at temperature already set/stuck on.

I tried it (cheap, solid plate with no hole) on my 407 (2007) with the same engine and there was no improvement to the running or MPG, but then there were no pre-existing faults. It did not complain or flag up any issues. By comparison on my previous C5 (2002) with the 136hp 2.2 litre there was a noticeable improvement in throttle pick up and MPG.

The 407 is junk, and I've yet to see any evidence that 508 is a better bet. And seeing as the C5 MkIII and the 508 are related, you may as well have a well specified MkIII Exclusive with a much nicer ride, look like the last generation of C5 will be the last hydraulically suspended car, and no Citroen large estate either, the DS5 looks like junk. Let's see. In six years I may look for a very end of line 2.2 170 Exclusive, if there are any left. Failing that a Vw/Skoda or Audi estate.

Diesel is sold to a BS/EN standard. Cars are designed to run on fuel that meets this standard. Which? magazine tested the higher performance and non supermarket branded fuels and the differences were tiny or non existent. I tried the fancy Shell stuff in my previous C5 and there was no difference. Up to you to read the manual about the fuels to use, and then buy those fuels. Failing that ask Shell for the exact technical details of the extra additives over and above the relevant BS/EN and see how much they can tell you. The main risk with all fuels is contamination. Providing that is avoided, there are, IMV, no risks to supermarket fuel.

Find a good independent Citroen repairer. I use Mid Kent Vehicles in New Hythe or Medway Citroen. Be worth asking around in your area.

Some C4s have had a software update to improve the Eco mode hassles.

Maplin sell label remover in aerosol cans, most effective, might be an ideal to use with rubber or disposable vinyl gloves though.

With some PSA cars the wipers sit up about 3" when the car is set to the automatic or intermittent wipe position. Set them to off to check if this is the case. On some cars off is not the lowest position. Worth trying to find an Owner's Manual for download.