to much polution

[moenbeer]

Hi all

My C5 HDi 2.0 from 2004, just failed inspection this friday. - The engine measured 7... something. Maximum is 3 for a diesel.

I really hope that it's not going to be too expensive to. But where to start? - Seems to run fine with no power loss. - the insp. guy told me it might be the turbo bearings so it's sucks engine oil. - It's almost at 280.000 km. and it does use some oil... but nothing major. - I ran some engine cleaning oil though it last summer, plus new filter and oil change. - Only added about 1-1.5 liters of oil since then... About 8000 km. 2000 km until next change.

when I got the car last spring, It had a anti-polution fault error. I later found out it was a cracked vacuum hose. But a new hose fixed the problem. But could it be the EGR valve? -
I dont want to put too much work into this car. - They dont go for much on the market, so I might just sell it to a scrapper if its gets too expensive to fix.

[Jaf]

First thing to ask: was the engine hot and had you taken the car for a hard drive just before the inspection? I mean low gear, high revs, until the black smoke clears up? ( known as Italian tune up )

[myglaren]

Black smoke from a C5?

We really need to know what it was 7 of when 3 is the limit but presumably particulate carbon.

Mine has similar mileage and although I generally change the oil and filters every 5~6000 miles or 4~6 months it hasn't been done for a year and about 8,000 miles
Oil never needs topping up between services. It is now very slightly below max and 2dL would put it up to max.
So it does look rather like engine oil being burned somewhere.

But as Jaf says, a good fast run that gets it breathing properly is often beneficial prior to a test, not that I ever bother (send it there, don't take it).

However, I never see black smoke from mine and never have from other HDi engines (PSA) other makes very often kick out black smoke though.

[white exec]

Does the car do mainly short runs, at urban speeds? This can build up soot in the exhaust, and result in a poor smoke test (opacity) figure.

Try half a tankful of good brand diesel (eg Esso - but no need for the expensive stuff), plus a dose of either Miller's Diesel Power Plus, or Wynn's Diesel Fuel Treatment, at 200:1 ratio (ie 10ml into 20lit of fuel), put into the tank before filling. Both these products contain effective cleaning agents, for both pump and injectors. (The 200:1 dose is for remedial cleaning; routine dose would be 1000:1.)

Then do the Italian TuneUp: decently fast run down the motorway, at sustained highish revs (around 3000rpm) for about 10 minutes. Periodic high speed runs are good for diesels, and keep the exhaust/cats more free from soot build-up.

Worst possible combination for a diesel is a diet of short runs, low speed, supermarket or budget diesel, and revs kept unnecessarily low.

Here, for our very thorough version of the MoT, the driver is handed a small leaflet, which advises a fast, hot run before putting the vehicle into the test bay.

[myglaren]

I am pretty much as described by white exec.
Short runs (four four-mile runs in 24 hours).
It does get booted on at least one of them but otherwise relatively sedate driving.

Not supermarket diesel but Torq which I have used for the past couple of years and consumption has risen from 400 miles per tank to 500. Still crap but not unexpected given the usage. Only long trips are to Citroen rallies although it has just come home from a week in Wales and 1,000 miles on the clock (not me in it, I was made to stay home and practice DIY )

Still never any black smoke and no problem with emissions at MOT time. Runs quite well too.

[Stickyfinger]

I saw a figure quoted by one of (can't remember which) the remapping guys, that a 1/2hour run at 3k+ revs (third gear) once a week keeps a most diesels smoke and carbon build-up (egr/dpf) free.

[moenbeer]

First thing to ask: was the engine hot and had you taken the car for a hard drive just before the inspection? I mean low gear, high revs, until the black smoke clears up? ( known as Italian tune up )

Engine was hot, but no hard drive. - slow trafic all the way..

[moenbeer]

Black smoke from a C5?

We really need to know what it was 7 of when 3 is the limit but presumably particulate carbon.

Mine has similar mileage and although I generally change the oil and filters every 5~6000 miles or 4~6 months it hasn't been done for a year and about 8,000 miles
Oil never needs topping up between services. It is now very slightly below max and 2dL would put it up to max.
So it does look rather like engine oil being burned somewhere.

But as Jaf says, a good fast run that gets it breathing properly is often beneficial prior to a test, not that I ever bother (send it there, don't take it).

However, I never see black smoke from mine and never have from other HDi engines (PSA) other makes very often kick out black smoke though.

I found my Haynes manual.. Its emission test about smoke density. - Normal is 3.0m-1 for a turbo diesel. - Manual says it could be EGR system, faulty injector, clogged airfilter.

I usually drive it hard, to clean out the engine. - I dont work far from home, so some times I take it for a detour on the freeway home, just to get it hot and really working.. and try to let it idle a min. or 2 in the driveway, before shutting it down. But it does do a lot of urban driving.

I don't know it makes a lot of smoke... dont see any thing in the rearview mirror. - But I'll get a friend to film it.

[moenbeer]

Does the car do mainly short runs, at urban speeds? This can build up soot in the exhaust, and result in a poor smoke test (opacity) figure.

Try half a tankful of good brand diesel (eg Esso - but no need for the expensive stuff), plus a dose of either Miller's Diesel Power Plus, or Wynn's Diesel Fuel Treatment, at 200:1 ratio (ie 10ml into 20lit of fuel), put into the tank before filling. Both these products contain effective cleaning agents, for both pump and injectors. (The 200:1 dose is for remedial cleaning; routine dose would be 1000:1.)

Then do the Italian TuneUp: decently fast run down the motorway, at sustained highish revs (around 3000rpm) for about 10 minutes. Periodic high speed runs are good for diesels, and keep the exhaust/cats more free from soot build-up.

Worst possible combination for a diesel is a diet of short runs, low speed, supermarket or budget diesel, and revs kept unnecessarily low.

Here, for our very thorough version of the MoT, the driver is handed a small leaflet, which advises a fast, hot run before putting the vehicle into the test bay.

I'll buy some diesel cleaner tomorrow and do some high rev. driving on the motorway during the next few days. And get a new airfilter.

Good thing about the MOT, is that the place is to next to a motorway.. So i just go that route next time.

[Hell Razor5543]

Before I took my C5 in for her MoT I went for a run down the A329M, and we had a look at the speed limit (maybe from the wrong side). On the test itself her emissions were VERY low (no advisories on anything, and only one attempt needed for the emissions part). OK, she initially failed the test, but for lighting issues only.

[chinkostu]

Not a citroen, but i took the wifes fiesta for an MOT a few weeks back and it failed horribly the first time around on emissions, second test was much better but still failed. For the retest i took it from my parents which is about 3 miles from the MOT centre, all the way around to the local bypass and thrashed the tits off it. Passed a dream after that.

The wife usually drives less than 6 miles a trip and its always slow runs through the town, so it must have been choked up.

[moenbeer]

I've been with the family on a looong trip ( 2000 miles + ) ... combined with some diesel injector cleaner in the tank, I ran it at 3000 rpm for a hour on the freeway, and even kept the revs up on the smaller road, by putting the aut. transmission in S mode.. or keeping it in 2. gear manually.
Seems to be quicker from around 2000 rpm and up.... - Got some more diesel cleaner additive... and even some to lower the soot buildup... and a new airfilter too, as the Haynes manual recommended. - I hope to get the car to a workshop this or next week to see if it can pass the test now. - I need to change a lower arm, and a brake hose at the same time anyway.

Thanks for all the tips so far... Tell you the results once I get it to a shop.

[white exec]

Sounding promising. Running (either Miller's* or Wynn's*, not sure about others) at a mix of 1:1000 for several weeks, or longer, will both really clean up pump and injectors, and improve the cetane value of the fuel, giving you some extra torque and smoother and quieter running.

* Both of these products contain naphthalene, a cetane improver. See Wikipedia for details.

[moenbeer]

Still no dice... even with anti-smoke and injector cleaning in the fuel, it still can't pass the test at the workshop... didn't even improve the numbers at all... - So they are looking at the injectors now.. - Got my finger crossed.

[moenbeer]

Got the car back from the shop - Their injector cleaning machine did the job.. and they fixed some more stuff and took it though MOT, that it passed with colours.

But i'll drive it differen than before, and run a bottle of inj. cleaner though it one and a while, so it won't clogg up again.

Thanks for all the tips