How do you change the air filter on a Citroen C4 hdi 1.6?

Answer 1

A difficult job due to access problems. Some mechanics begin by removing the bonnet. Then remove wiper arms (may require 2 leg puller to pull off taper) (16mm hex nut). Remove plastic engine top cover. Access to filter which is behind engine requires removal of plastic rivets which secure sound insulation (be careful, there are push clips to the rear underneath as well which need to be removed also). Undo 2 T25 screws which secure brake fluid reservoir. Move reservoir towards battery side and secure to bonnet hinge using string or shoelace. Remove plastic crossbar in front of windscreen by undoing 10mm hex bolt on battery side of car. Pull bar slightly forwards and move towards battery side of car, enough to disengage lug. Remove lower windscreen trim by lifting up from clips. take care, this job is difficult and tedious. Remove air inlet trunk by undoing M10 bolt on chassis rail behind head light on battery side. Rotate air duct slightly anticlockwise and disengage. Remove 3 approx 4mm Allen head screws from top of air filter box, behind engine (left hand screw requires lift up fuel line fitting from top of engine). After disengage trunking, you need to remove 3 torx screws from air box outlet pipe (underneath screw hard to access and requires flex screw driver or wobble bit ;take care with O ring). Lift up top of air box, remove filter and replace after vacuuming and brushing to remove all dust and dirt. Installation is a reverse of the disassembly procedure. Take care in installation as lower windscreen trim is easily broken. While removed, a good idea to replace pollen filter which is located to the left of and behind the air cleaner box on the front wall of the cabin. After pulling the cover forward, slide filter forwards and clean or replace. Also a good time to renew cartridge fuel filter if due. Recommend glue with silastic a Ryco A32 air filter or equivalent on to the air horn behind the battery side head light, which is the cold air entry area. It fits well with a minimal trim of the forward part of the plastic cover (scissors and sandpaper) and removes the need for further original filter changes as it can simply be removed and replaced every 15 000 kms. Make sure u glue a thin plastic or aluminum plate over the distal end of the filter to prevent unfiltered air entering. You now have a double air filtered engine and do not need to spend excessive amounts of time or money changing your genuine air filter next time. All of the above works for the similar 1.6 HDI Peugeot 307 or 308.