406oc.co.uk

Hi guys, newbie to the site so be gentle with me

I changed the oil, oil filter and air filter on my 406 HDI 90 earlier in the week and all was fine, today I change the fuel filter and now I am getting the "Antipolution Fault" displayed and the car is running in limpmode, any ideas what the problem could be.
Also the engine management light is now on, i think thats what it is anyway, it's a yellow symbol directly beneath the milage.

Any help would be much appreciated.

Many thanks....Tom

Hi Tom & Welcome

The antipollution fault is Pug-speak for any engine management problem.

As you've worked on the engine recently, the first thing to do is to check carefully that everything's back as it should be and that you haven't inadvertently distrubed anything else.

Failing that, low fuel pressure / air in the system is probably the next suspect. Do you know if your's is a Bosch or Siemens system?

If not, let us know the age and whether or not you can find a priming bulb on one of the fuel pipes leading to the filter. (if you do try squeezing it a few times to see if it's firm, or becomes firm).

You could also post the VIN code, then we can look up what equipment's fitted for you

Hi Dogslife, thanks for the reply and the welcome,

I'll check out the fuel system and get back to you, the year is 2000 on an "x" plate and it's a Rapier saloon.
There is no priming bulb that I can see anywhere. The air filter I changed was really clogged up and the pollen filter
looked more like a squirrels drey so I thought changing the fuel filter would be a good idea also, nothings simple.

It's a bosch pump and the VIN no:vF38BRHYExxxxxxxx.

Everything looks ok, none of the connectors are unplugged and no pipes cracked or sucking air
wish i'd left it alone now

Hi guys, bit of an update, after a day of much head scratching and cursing the Antipollution fault is still showing for a few seconds after the engine is started and the engine management symbol is on all the time but now when the car is switched off it stops instantly instead of the couple of seconds overun which it had earlier. I'll take it for a spin later and see how it runs.

Before all this fuel filter stuff there used to be a "coolant temp to high" displayed when the aircon was switched on but the aircon still worked, tried it earlier with the engine just ticking over and there is no longer this message showing, does the Antipollution Fault overide all other faults?

An update from a few days ago, the car starts fine and ticks over fine so I took it for a short drive
Theres no power and black smoke and when going up a slight hill, also when the throttle is pressed for more power there is a tapping noise similar to a petrol car when it is "pinking", when stationary and revved to about 2500rpm there is black smoke and soot blown on the ground.
What would the symtons be if it was a fuel starvation problem? I ask this because it was an aftermarket fuel filter I used and wondered if this might be the problem.
The engine management light is no longer lit and the Antipollution Fault no longer comes on.

Any ideas fellas.

ATB

Tom

I think that sounds like your egr has packed up

I reckon the Airflow meter is unplugged or something?

Ok, thanks for the help. If it is the egr would this cause the tapping chattering noise. I have read about the egr, is it operated by the vacum pipe? when vacum is sucking does that open the valve or close it, how can I test if it is working properly.

Regarding the air flow meter, where is it

I'm not at home at the moment so can't check anything on the car.

ATB

Tom

To be honest I don't really think it will be the EGR, when they fail they tend to let too much exhaust gas back into the inlet and cause some more smoke but not clouds of it. From the clattering noise and smoke your fuelling's out and it might be because the air flow meter is at fault (it's the next bit behind the air filter piping going towards the turbo).

I think you need to give every sensor plug a wiggle to check the easy things first and then start looking at the vacuum lines from the solenoids on the bulkhead etc...

Is it possible that there's an air leak around the airbox and pipework as it won't like this very much - maybe the airfilter's not sitting right in the box etc?

Fairy nuff Welters, I was wondering about the tapping noise

Hi all, I checked the air flow meter and one of the two delicate bits of wire are broken I must have done this when I was giving it a wipe out the other day, I'll try and source a secondhand replacement as I suspect buying new would cost an arm and a leg. Also there is a connector directly beneath the fuel filter which goes to the fuel pressure sensor, the terminals of this were pretty corroded so gave them a good clean along with all other connectors.
Hopefully the air flow meter is the source of the problem but I'll have to wait till I have the replacement to find out.

Thanks to all who have given advice, much appreciated.

ATB

Tom

That'll be it then! they are delicate and easy to damage.

Welly wrote:That'll be it then! they are delicate and easy to damage.

Expensive to replace as well, £70 +vat

Scrappy, Fleabay?