C5 depollution warning light

bweather

Member
Fellow Frogger
Joined
Jul 31, 2011
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83
Location
angourie
Loud clicking noise coming from the motor when I opened the door even though the engine was not turned on. That was yesterday. Today the depollution system warning light has come on and I think there may be a causal connection between the loud clicking and the warning light. Any clues? The car is a 2.2 2008 HDI wagon, the last of the old shape.
 
I think there are a couple of vacuum solenoids down the front of the motor. Also, there is a large air mixer valve on the intake air piping down and directly in the front of the engine. Oil residue can enter the electronic side of it and possibly cause a malfunction.
See if the noise comes from any if those items.
 
My same model sedan used to do all kind of things, and warning lights came and went. Usually they just went away on their own. It's a Citroen - see if it fixes itself or anything else happens before you spend money and go crazy trying to find out 'why is it so'.:)
 
I had same problem on my 2008 C4 diesel, the de-pollution light was hard on, although I had no clicking noises as described. The car was still driving and behaving normally.
In my case it was due to an old battery. Mine still had the original French battery as fitted in 2008. I replaced it last year and all is good now.
 
That's sensible advice. There is a good mechanic in Yamba and I will get him to have a quick visual check of the front of the motor and unless there is something clearly at fault I will let sleeping dogs lie for a while.
 
Will check the battery also. I am not a mechanic's bootlace but I suspect batteries on modern cars have to do a lot more work than they once did.
 
Plus one on the battery check.

Is it the original battery?

Being a 2008 it is likely that if original it would be at about the end of its life. These cars are very hard on batteries with the amount of electronic controls and just a small drop in voltage can have a major impact. Our 2003 had its second battery replaced a couple of weeks ago when it went from working to not almost instantaneouslt. Still averaging over five years from the batteries, not too bad I guess.
 
Thanks Gembee and PeterO. Have checked the battery and all ok but I do understand the games a poor battery will play with a C5.

my mechanic has detected the noise as coming from a small electric motor at the middle of the front of the motor which is a throttle I think he said with a butterfly action which has been frustrated in its work possibly because of a small build up of sludge. This is playing havoc with the electronics. He is going to attempt to clean it on Monday and I will report back to Monday.

I think David may be on the money.
 
Much appreciated David S, bigkev14, Gembee and PeterO. A dirty throttle valve was happily clicking away and my mechanic fixed the problem using an intake system cleaner and then reset the fault code. All!s well that ends well.
 
Good news. See how it goes, but you may find you need to open it up and clean out the electronics side of that valve. If oil/fuel residue is passing the spindle seal, you will eventually be better off changing the unit.

Batteries really need to be tested with a load or a proper testing unit. Over 3 years and they tend to be suspect. A weak surface charge can show as OK if just measuring the voltage with a multimeter and that can lead you to an incorrect conclusion.
 
Points taken David S and I thank you again for your interest and wise counsel. Cross my fingers!
 
Here is the parts diagram showing the mixer/doser valve 0345F7 on a 2.2HDi twin turbo C5.
Part number is 0345F7. Seems to be the same for all of this model.

C5_22HDi_Doser.JPG
 
OP later advised of a broken tooth on a cog in the mixer. Fixed by replacing the mixer unit.
 
Looking at taking off my Butterfly and giving it a clean as it's pretty gunky. I'm just a uni student so do a lot of my own work. Any tips would be great. Also, is it as simple as reconnecting it after? Or will I need to program again. Citroen C5 3.0 automatic petrol 2003
 
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