C5 2.2hdi Auto Anti Pollution Fault - Egr Question

[Guest H19SNS]

Had my C5 nearly a year now, when I got it had the dreaded anti-pollution fault; replaced fuel comp, DPF, EOYLS fluid and cleaned the EGR return pipe and all cleared until a week ago. I have done about 16K miles in this time.

 

I think the AP fault is somewhere else, so am trying to do some troubleshooting.

 

Does anyone know what the vaccum pressure should be in the EGR line and is this dependent on feedback from the emission control system (i.e. does it change or should it remain constant).

 

I am wondering whether the bosch vac control valve needs replacing.

 

Any pointer to troubleshoot this appreciated.

 

Neil

[Ronin]

I believe its variable m8 with back pressure of the engine, temperature of the gases at the time which, in turn can change the volume & mass in manifold absolute pressure.

 

Usual faults on the vaccuum and valve itself is due to obstruction and clogging.

 

 

You could try some compressed air in the vaccuum tube to see if there is any obstruction first m8.

 

I know this is not for the C5 but the principles are the same. Try here m8 ok.

http://www.asashop.org/autoinc/dec97/egr.htm

[Guest H19SNS]

I believe its variable m8 with back pressure of the engine, temperature of the gases at the time which, in turn can change the volume & mass in manifold absolute pressure.

 

Usual faults on the vaccuum and valve itself is due to obstruction and clogging.

You could try some compressed air in the vaccuum tube to see if there is any obstruction first m8.

 

I know this is not for the C5 but the principles are the same. Try here m8 ok.

http://www.asashop.org/autoinc/dec97/egr.htm

 

 

Excellent link; Many thanks!!!

 

Reading this, and comparing to what I have seen, I am beginning to think all is ok with my EGR system;

 

Having replaced the DPF and Eolys 16K ago, I can't see that it can be these unless there is a fault on the fuel flap switch and the Eolys is not lasting as long as it should.

 

It is a shame that you have to get the dealer/indy to read the codes etc.

 

Reading other posts - someone mentioned that the swirl chamber can be at fault - is there any way to diagnose this without going to a dealer/indy.

 

thanks again for the reply

[Ronin]

Excellent link; Many thanks!!!

 

Reading this, and comparing to what I have seen, I am beginning to think all is ok with my EGR system;

 

Having replaced the DPF and Eolys 16K ago, I can't see that it can be these unless there is a fault on the fuel flap switch and the Eolys is not lasting as long as it should.

 

It is a shame that you have to get the dealer/indy to read the codes etc.

 

Reading other posts - someone mentioned that the swirl chamber can be at fault - is there any way to diagnose this without going to a dealer/indy.

 

thanks again for the reply

Hmmm this is a wierd one. I'm thinking down a different path of logic here.

I'm just wondering if we can resolve this fairly easy here but it all depends on what your answers to a few questions are m8 ok.

Is it a generalised AP fault on the display or is it specific?

What symptoms are you experiencing while driving the car if any?

What kind of regular journey do you do in the car?

 

I'll give you an example of what I mean m8...

(I travel to work monday through friday. it's 50 mile round trip on mixed roads A and B roads. The car can travel at a constant speed for about 8 miles between two junctions etc. The car is staitionary at a busy junction in the morning for about 5 minutes and then further along a temporaray set of traffic lights for a further 4 minutes. The car has had only short journey's to the shop over the weekend of about 1.5 miles)

 

This kind of info is invaluable m8 and typing it out like that leads to some surprising, if not obvious reasons why DPF/ AP and EGR faults can occur. For instance I would tend to think if your journey was similar to what I have described the fault would come up eventually without fail.

Here is a quick fix that many on here have tried with some success. My Grandfather who has the same model as you has done this also after getting advice from a main deal service manager with regards to AP faults. He now does this every 6 month.

 

Buy some diesel additive/ injector cleaner and add it to a fairly full tank. Take the car out for a long steady run of 40 + miles and a steady speed of 40 mph (important) even if you have to get on the dual carraigway at night. The car has to keep at this constant speed for at least those amount of miles with no interuptions. Ignore the cursing truckers!

It may sound daft but trust me, it works on general AP faults. You will find that when you get home and restart the engine the next morning the fault will have disapeared (hopefully)

It works by giving the engine and DPF a chance of burning off the excess carbon build up at a constant nominal temperature. It also does the same to the whole fuel system. A lot of owners get hung up on AP faults expecting the worst or start replacing everything associated but all the car is saying is "I need a good clean out"

 

It's certainly worth a go m8 as it works out about £11 for fuel and additive which is a hell of a lot cheaper than an hours labour getting a fault check done.

 

If it's still no better or if the car is not driving as it should.Then you know pretty much for sure that its an ECU or electronic issue. I would take it for a fault code check for that.

Let us know how you get on m8 ok :lol:

[Randombloke]

Reading other posts - someone mentioned that the swirl chamber can be at fault - is there any way to diagnose this without going to a dealer/indy.

 

This was the fault on my C5 the only time it ever went AP faulty.

 

With the swirl chamber control valve, one of 2 things happens:

 

The control rod joint breaks - easy to see by inspection. You cannot buy the small plastic ball joint or the rod on its own.

 

The diaphragm splits and leaks, difficult to spot but could be tested by connected a small length of clean tube and blowing gently to see if there is a leak.

 

The diaphragm on mine went, so I posted it to another forum member with a broken ball joint. I bought a new valve and he made a good one from 2 duff ones.

 

HTH.

 

Ronin is more likely to be right, though.

[Guest H19SNS]

Cheers Guys, your responses are much appreciated.

 

Will certainly check the swirl chamber control valve;

 

However, I too think Ronin may be right, the AP fault has been intermittent, so fits that a good clean out would suffice.

 

My commute is Mon-Fri, 56 miles each way (total 112), plus around 100 motorway journey at the weekends; for the daily commute around 20ish miles of B roads and then A3 & M25, so car is stop start for some of journey say around 25 mins and cruising at reasonable speed (when the M25 isn't jammed!!) for the majority. I have not put injector cleaner in for fear of upsetting the system, but will follow your advice and give it a try.

 

At the weekend, I changed the oil, and inspected the EGR vac lines, blowing through the control valve and lines and the fault has cleared for today's journey. However, I am waiting to see what happens as last week I managed 3 days fault free, then Thur/Fri fault appeared.

 

Fault is Anti Pollution System Faulty and then ASR/ESP System Fault; I go into LHM for that journey, restart an no LHM, AP and CE light still on, but LHM does not happen for around another 50 miles or so.

 

Driveability is fine when not in LHM, the only thing I can say is when you release the throttle and are slowing down, the car does seem slightly lumpy at times.

 

This is my first Citroen and have been getting fed up with AP, but your posts have provided some guidance to keep the faith a little longer.

 

I have ordered an ELM 327 OBDII reader, will let the group know if it works with the C5.

 

Have been used to DIY for service and repair, so still getting used to C5 diesel.

 

Regards,

Neil

[Guest H19SNS]

Quick update: Elm 327 no good with freeware scantool s/w available on the internet, so I have had no luck in being able to read the fault codes myself.

 

Still getting the AP fault, but have not tried your 40miles@40mph yet. The AP and LHM fault occurs when cruising at ~70mph on the motorway, short journeys are fine, just when you think the car is running well on the m'way the fault light comes on.

 

The plastic rod you guys spoke of to the swirl chamber is intact, I can't get at the other end to check the diaphragm, but when I push the rod I can here the diaphragm move.

 

I have a fairly bad oil leak, it is coming from the pipe that connects to the inlet manifold (bottom pipe) to a long tube down the radiator into a T piece that goes to the intercooler & large plastic pipe @ bottom of engine. There is alot of oil coming from behind the jubilee clip, I have resecured, but to no avail. Is this a breather/back pressure problem??? There is a small amount of oil on the bottom 1/3 of the intercooler, so will have an air leak there.

 

Again - any pointers/thoughts appeciated.

[davidad]

My 2.2hdi has just had a similar AP and occasional ESP (causing the car to go into LHM) fault which the local Citroen dealer traced to the diaphragm you mention. It was replaced on Monday this week and seems ok so far but I've only done about 50 miles. I've got a longish motorway journey to do on Friday so I'll see how that goes. The M6 in LHM is not much fun.

[Randombloke]

The plastic rod you guys spoke of to the swirl chamber is intact, I can't get at the other end to check the diaphragm, but when I push the rod I can here the diaphragm move.

 

Can you get at either end of the air pipe going into the valve? You might need to connect a bike hand pump up to gently see if the diaphragm is ruptured. Yes, you can hear it, but is it it intact?

 

I have a fairly bad oil leak, it is coming from the pipe that connects to the inlet manifold (bottom pipe) to a long tube down the radiator into a T piece that goes to the intercooler & large plastic pipe @ bottom of engine. There is alot of oil coming from behind the jubilee clip, I have resecured, but to no avail. Is this a breather/back pressure problem??? There is a small amount of oil on the bottom 1/3 of the intercooler, so will have an air leak there.

 

The lower pipe feeds both the intercooler and a water/air heat exchanger that can be used to warm the inlet air. It comes from the turbocharger so any large amounts of oil must be from that or the breather valves/system.

[Guest H19SNS]

There is a fair amount of oil coming up to the top of that heat/water exhchanger and leaking from the rubber hose at the top. Any ideas what could cause this? things to check. Cheers, Neil

[Guest H19SNS]

BTW: Thanks for the tips re:diapraghm, will try to check with the mitivac at the weekend and report back.

[Randombloke]

There is a fair amount of oil coming up to the top of that heat/water exchanger and leaking from the rubber hose at the top. Any ideas what could cause this? things to check. Cheers, Neil

 

Play in the turbo bearings or a tired oil seal?

 

Have look and see if you can see any oil being fed into the system from the breather.

 

Also, that hose may have perished. It shouldn't be leaking there anyway, as that is part of the pressurised inlet system. I would look at the hose and the end of that exchanger to see if there is a problem or damage.

 

Be worth getting the RTA manual if you are going to go into depth.

[Guest H19SNS]

RB - you was right!!! When I got to the swirl chamber control valve I found the vac pipe was split - replaced pipe and working a treat now!

 

Oil is getting into the air intake via the hose that comes from the rocker cover next to the EGR valve. Have taken the whole plastic cover off and can't see any damage or blockage. The oil seems to be scavanged from two long pieces of plastic that drop down into the cam area.

 

There are two small holes in the plastic cover where threre is a round bit. It looks like someone has prev tried to get it off with a screwdriver. Should these be there or shall I seal with araldite. Will try and get a pic in mo.

 

Also, could the fact that the swirl chamber diapragm was not working have cause wrong pressures in the system and thus oil to pass by this breather.

 

Any ideas/thoughts?

 

Am in the process of changing the bottom pulley too as I have the bit betweem my teeth.

 

Feeling alot happier about the car now.

[Guest H19SNS]

Citroen C5 photos

 

Here are some photos of the rocker cover and breather. Cheers Neil

[Randombloke]

Here are some photos of the rocker cover and breather. Cheers Neil

 

The only thing that I can think of is that the rocker box will be under some slight pressure owing to very slight leakage from valve stems, etc, plus some slight blow past the pistons into the crank case.

 

You need to fix the hole, I think! This should then reduce oil leakage......

[Guest H19SNS]

The only thing that I can think of is that the rocker box will be under some slight pressure owing to very slight leakage from valve stems, etc, plus some slight blow past the pistons into the crank case.

 

You need to fix the hole, I think! This should then reduce oil leakage......

 

Thanks; I've sealed the holes and will see how we get on now that the Swirl Valve diaphragm is sorted. If need be, I'll run the breather into a catch bottle and seal the intake. All is back together and the car is ruuning like a watch with new bottom pulley.

 

Thanks again for all your posts and input - much appreciated.

[Guest H19SNS]

Just a quick update; tried the car today for first long journey since fixing the vac leak to the swirl chamber control valve. Happy to report no AP faults and a good improvement in MPG. Previously I could not get better than 42.8 for that journey, over mixed motorway/A/B - 116miles, now reporting 46+.

[wesley5]

Hi, I had same problem with my 2002 2.2HDi sx. I had all four wheels rebalanced by experienced tyre specialist, using an adapter plate added to shaft of the wheel balancer which cured the dreaded anti pollution fault, esp/asr and service lights. It is early days, can only hope. wesley5anti pollution fault