C4 Picasso Hints and Tips

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C4 Picasso Hints and Tips

Post by RichardW » 07 Jan 2013, 22:49

There's not much about maintaining these on the net yet, and there's no BOL (although there is a Revue Technique which I might invest in!) so as I do jobs I thought I'd post up here how to do it for future reference.

Pollen filter

Oh, this is a right game. They didn't swap over the pollen filter / AC pipes for RH drive cars, so the pollen filter is in the driver's footwell #-o It should be easier on cars without a clutch pedal! Note there are TWO filters - so make sure you get both.
1 Remove the plastic trim from under / behind the pedals. There are some screws, and a tight clip into the A pillar - mine is broken now, but it should come out with a trim removal tool.
2. Peer up above the pedals and on the side of the heater box you will see a black plastic access hatch with a clip at the bottom, extract this and then you should be able to see the end of the filter.
3. there should be a tab on the end of the filter to pull it out, but you will probably need a pair of long nosed pliers to get it going.
4. Now you will find that there is not enough room to pull it straight out - it fouls on the blower unit, and there is a pin that sticks out of the housing that catches on the pleats. After a lot of pushing and pulling I eventually managed to get it out, by pushing my left hand up behind the clutch pedal and pushing on the face of the filter so it clears the sticky out pin / housing whilst pulling it out with my left hand. Not easy!
5. The second filter lives under the first one, so you need to prize it up with the pliers again then pull it out as before - it comes out easier though. Expect both filters to be knackered after this!
6. Refit is reverse of removal, they do go in a bit easier though.


Looks difficult at first, but in fact not that bad. Observe the normal rules about disconnecting batteries on multiplexed cars (in fact ours didn't lose the radio, keys, or window anti pinch despite being off a while).

1. Remove the air inlet pipe - undo the 10mm bolt into the chassis rail, and then wiggle out the end piece and first pipe EDIT - this bit can in fact stay, there is enough flex in hte first pipe to unclip the bayonet without removing the end. Second pipe can now be removed by pulling / levering it off the clip on the end of the engine, and then untangling it from the air box. I suspect it should have a clip on it, but it's missing / broken on ours - you can reach this (just!) over the top of the air box.
2. Unclip the +ve terminal, remove the red cover on the top of the battery (squeeze the clips at the front) and then undo the 2 ring terminals to disconnect the wires onto the power board. Now unclip the power board off the top of the battery - there is a press clip in the channel in the LH (as you look at it) side of the board. The board can then be eased out forward (you might need to reach over the battery and ease the cable bundle over the back of the battery). higher spec cars have a second power board on the front of the battery - no idea about this, ours doesn't, but I presume it can be removed similarly to above.
3. Unclip the wires from the front of the battery cover, then remove the cover - just pull it up and forwards and the clips disengage.
4. Undo the battery clamp on the side of the battery and -ve terminal, and then lift the battery out.

Refit, as ever, is reverse of removal! Observe the precautions before powering up.

Air filter (1.6 HDi)

Another stupidly difficult service job! It's on the back of the engine.... If you're 6ft tall like me, then best to pop the front on ramps 6 or 8 inches to reduce stooping.

1. Remove the secondary air inlet pip as per the battery above. Remove the engine cover - it just pulls off.
2. Remove the air box to turbo pipe - I had to lever the pipe off the turbo with a big tyre lever....! There's also a clip on the cam breather that you need to release at the same time as getting it off the turbo.
3. Unplug the MAF sensor (no need to unbolt it from the air box lid)
4. Undo the 3 screws that hold the lid down. They are 4mm allen screws - and you need one you can drive with a ratchet as they are long, and stiff to turn. one is visible to the side of the MAF, the others are on the front edge, one each end of the fuel primer. You don't need to take them right out, just far enough to release the lid.
5. You can now manipulate the lid off and out - it is clipped onto the back of the engine with the same sort of clip as the hose, so you might need to lever it off; and it has a series of lugs that slot in at the back.
6. Change the filter and put it all back together. Be glad you don't have a a C4 car where the wipers, scuttle, and sound deadening need to come off as well....!)

Fuel filter

Do this at the same time as the air filter, as you need to remove the pipes to the air filter anyway! The filter comes as a complete unit (nearly - see below!), and is best changed every other service with the air filter. If it starts to get clogged it can cause running problems and limp mode.

1. With the air filter lid removed, unclip the top fuel pipe - press in the white bit whilst pulling it off the stub.
2. Remove the second, lower, fuel pipe - this is on the back under the first pipe, and barely visible - you only need to press in the side of the clip you can feel, but it's awkward and
3. Press in the clip on the left of the filter and wiggle it up, tilt it forwards a bit and disconnect the top electrical connector - you need to lift up the small tab under the connector to release it.
4. Rotate the filter back the other way and unplug the other connector on the bottom (just goes into a blank port :roll: ) and the drain tube.
5. On the back of the filter there is heater unit, and this must be transferred across to the new filter. There is a clip under the top spigot that you need to lift, whilst levering the unit across the filter to release the spigot on the end, and holding the filter! I had to put it in the vice as a third hand, and lift the clip with a pair of gas pliers.
6. Clip the heater into place on the new filter, and then refit to the car, remembering to refit the connector and hose on the bottom! Reconnect the fuel pipes (just push on till they click).
7. Prime the filter - just squeeze the bulb on top of the engine a lot. They can apparently be difficult to bleed so I did a bit tlll it stopped gurgling in the tank, refitted the air piping, then did some more, waited a bit and did some more. Re-start the engine. If it won't, then pump more till it does!

Light bulb check

Big brother is watching you! Access the warning messages via the vehicle parameters menu, and it will tell you if any bulbs are faulty. Found this out by accident scrolling through the menus after the battery. It said side light faulty (front NS was off but I think I knocked it when doing the battery as it came on when I twiddled it). It also said NS brake lamp out - and it was too! Damn clever.

Rear pads

Can be changed without needing a Lexia. Best to have a wind back tool (cheap on e-bay) - you need a LH and RH thread one.

1. Set the handbrake auto function off via the screen menu (vehicle parameters, parking assistance I think). Switch off and it shouldn't set the handbrake.
2. Jack up and remove the rear wheels - note it appears that there is no easily accessible subframe, so you have to jack and support under the sills.
3. Unhook the handbrake cable, and then unscrew the damper off the bottom bolt - you can get hold of the neck with a pair of water pumps pliers / mole grips, bit difficult to get hold of.
4. Remove the two bolts top and bottom of the caliper (top is a bit awkward behind the brake pipe), bottom one has the thread for the damper sticking out.
5. Lift off the caliper, and remove the pads from the carrier - in board ones on mine took some persuasion to get out!
6. Remove the lid off the fluid reservoir, and wind the caliper piston back. I wound mine clockwise on the right, and anti-clock on the left. Afterwards I wondered if this might be the wrong way, but they went in OK. I will monitor, and hope that I haven't wrecked the calipers!
7. Refit the pads (I had to file the paint of the ends of the inner pad to get it back in), and then caliper over the top, and finally the bolts and the damper.
8. Do the other side. Start the engine, and press the brake pedal gently a few times to push the pads back out, then firmly to adjust the handbrake. Re connect the h/brake cables, refit the wheels, and drop it down.

I then took mine for a run to bed the pads a bit, and give several firm applications of the brakes to make sure they were adjusted up before applying the handbrake. Seemed to work OK and then I re-enabled the auto function. Seemed remarkably easy overall - just hope I haven't done the calipers in!

Oil change (1.6 HDi)

Easy enough, but due to the marginal lubrication system on these engines, it MUST be done hot and out the bottom, no sucking it out! You need a 27mm socket to get the lid off the oil filter - and probably best to have some gloves on hand to remove the filter from the lid! Be sure to use a low ash / SAPS oil.

1. Jack up, or put on ramps and remove the undertray - there are 3 13mm bolts at the front which are OTT, but there you go!
2. Drain the oil out the bottom, put a rag under the oil filter, and then unscrew the filter lid - a 27mm socket on a long extension gets it - the rag is required as otherwise it leaks oil all over the clutch slave cylinder.
3. Remove the filter from the lid - it's a tight fit, so some gloves are best.
4. Clean out the filter housing, and pop the new filter in, engaging the spigot in the the housing. Change the seal on the lid, and then screw it back on.
5. Refit the plug, and refill - it only takes about 3.5 litres, so don't overdo it!

Someone on here recommended that you check the injector securing bolts at the same time - if you start to get injector blowby it can take the turbo out pretty quickly, and getting the engine clean enough to avoid ruining the replacement is near impossible. There are 2 7mm allen bolts on each injector you need a ball ended one to get the back nuts. Don't overdo it, as the torque is not high!

Cooling fan

Ours was making a horrible noise the other day - tracked it down to the cooling fan. I had it out to see if it can be fixed, but the answer is not easily, so I have bought a new one (not too bad at £117....) . Once I have a new one in, I will try and get the old one apart and see if I can get some lube in the bearing - pictures if I do!. To get it out:

1. Remove the plastic cover in front of the slam panel - prise up the centre of the clips, then pull them out.
2. Slide the electrical connector across to relese the clip on back, then slide up the yellow tab, and lift the tab underneath which should allow it to pull apart.
3. Ease the clips and push in the flap panel behind the wire.
4. Undo the 4 10mm bolts around the fan and lift it away from the rad, feeding out the wire
5. There is just enough room to wiggle the fan out to the left of the bonnet release lever.

Front pads

Pretty standard stuff, but some pointers:

1. The caliper holding bolts are inside rubber tubes, with a plastic cap on, this keeps the crud out, and the bolts in good condition - which is just as well as they are 7mm allen key. Best to use one on the end of a ratchet, as the upper one is a bit awkward under the brake flexi. Once you have them undone, lever them back into the calipers using the shoulder so they clear the caliper carrier.
2. The inner pad is clipped into the piston, so comes out with the caliper, and means you need to lever the caliper out, but it comes easy enough, once you have levered off the anti rattle spring (more on that later!).
3. I used my wind back kit to push the calipers back in, but a G cramp will do just as well. If you push the piston right back in, then that's too far really. I found that the bolts then fouled the caliper (you are restricted in the caliper position, as the pad is clamped to it!). Bolts are easy to push out from the back, and can then be pushed back in once the caliper is refitted.
4. Last bit is putting the anti-rattle spring back on. Ho ho ho!! If you put both loops of the spring under the caliper then line up one end with the hole, you find that the other end is 1/2" short of going in! Eh?? Took me 15mins to get the first side on - put the top end in the hole and the loop under the caliper, the put the other end in the hole with the loop in front of the caliper. Hold the end of the spring with with long nosed pliers, and then lever the loop under the caliper with a big screwdriver. Second side went straight in.

Scuttle drains

These get blocked quite easily, resulting in wet interior, fan not working, and possible water sloshing around as you go round corners! East to rectify:

Pull back the wheel arch liner behind the front wheel on both sides - you can do this without jacking it up if you put it on full opposite lock. There are 3 plastic clips in the liner, remove these (note if it's fitted with mud flaps you'll need to remove these too), then pull the liner forward. Reach up behind, and you will find a small rubber square drain tube, pull this out (it's just clipped into the scuttle) and a load of water will rush out. Clean out the tube, and the scuttle above with a finger, then flush it well from above. Put the tube back in (I remember it's a bit awkward, but it will go - there is a plastic clip that needs to be put on the tube, and it only fits one way). If it's a freezing cold day you will now be soaked to the armpit in freezing cold fetid water, but the car won't be wet inside anymore!!

Remote fob battery

The car will tell you when it needs changing, but beeping at switch on, putting up the SERVICE light and "REMOTE CONTROL BATTERY FLAT" message. It does goe away after a couple of seconds though. Handbook incorrectly refers to an 0523 battery - in fact it is a 1620. Plenty available cheap on the bay. Remove any key ring from the fob, then open the key blade, and lever the case apart at the back. Fit the new battery and pop it back together. You may need to re-synch the key - this is apprarently done by turning on the ignition, and then pressing the lock button for 10seconds or so. Didn't have to do it on ours.

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Re: C4 Picasso Hints and Tips

Post by harryp » 09 Nov 2015, 15:23

Richard, another excellent article - thankyou 8-)