failed nct - emissions

angeldaisy

My 99 octavia 1.6 just failed on emissions

Low idle CO 2.85 vol% HC 385ppm
High idle lambda 0.83 CO 6.04% HC 577ppm

The cat was replaced about a month ago but it obviously hasn't sorted out the problem.

What else can I do? Any chance dipetane and a good run would do the trick or am I looking at more expense?

jca

Those CO figures are very high. Why did you replace the cat a month ago? Is this a re-test? I'd start with the basics first, full service including the air filter. Does it sound lumpy when idling, maybe its only running on three cylinders. Are there any lights on on the dash? Might be no harm to get its computer interrogated for fault codes.

angeldaisy

jca wrote: »

Those CO figures are very high. Why did you replace the cat a month ago? Is this a re-test? I'd start with the basics first, full service including the air filter. Does it sound lumpy when idling, maybe its only running on three cylinders. Are there any lights on on the dash? Might be no harm to get its computer interrogated for fault codes.

It failed the first time so the mechanic worked on it and found a prob with exhaust he fixed that and it was retested andfailed again on emissions so mechanic said it needed a new cat, this was done but obviously hasnt fixed the problem. I just dont know what to do ? Im assuming that air filters were changed - but hubby took it up and im not sure exactly what was done. It sounds fine as far as I know and there are no fault lights on dash.

jca

Did the guys in the nct give you any clues, anything out of the ordinary show up? I don't have much faith in your mechanic to be honest. You really need to get its computer read and start from there. It could be that the lambda sensor has failed, this component samples the exhaust gases and controls fuel amount being delivered as the engine requires it. It could be the coolant temperature sensor gone faulty and the computer thinks the engine is cold and is over-fuelling as a concequence which will also give high CO readings. As you can see without starting logically you could end up spending lots of money between re-tests,components and garage fees and still not have it sorted. Is it gone heavier on fuel lately?

George Dalton

It is hard to be sure without seeing the car but judging from those readings excessive oil consumption is the cause of the problem here. The only 100% solution to the problem is an engine rebuild. It is really common on these engines as they get older.

harg90

George Dalton wrote: »

It is hard to be sure without seeing the car but judging from those readings excessive oil consumption is the cause of the problem here. The only 100% solution to the problem is an engine rebuild. It is really common on these engines as they get older.

shes burning fairly rich tho? id try a lambda in first.

plus what sort of cat was fitte?

your better off with a good second hand cat as a possed to a brand new spurious one..

the spurious, even bosal, are dung, tbh you'd wana have it fitted the day of the test to have it pass.

ManMade

Is there any truth to adding sunflower oil to the diesel to help pass the emission test?

And what I presume is true, drive the car in a low gear on the way to the test, outside the test centre rev it hard for 5 seconds 2 or 3 times helps clean the exhaust out.

George Dalton

harg90 wrote: »

shes burning fairly rich tho? id try a lambda in first.
.

Oh there is no doubt that it needs a lambda now as well. Fitting a new one might get it through this test along with the new cat already fitted but by this time next year the new lambda and cat will be ruined by the oil in the exhaust.

harg90

George Dalton wrote: »

Oh there is no doubt that it needs a lambda now as well. Fitting a new one might get it through this test along with the new cat already fitted but by this time next year the new lambda and cat will be ruined by the oil in the exhaust.

if the cat isint already shot get a test on her and let her off :L

harg90

ManMade wrote: »

Is there any truth to adding sunflower oil to the diesel to help pass the emission test?

And what I presume is true, drive the car in a low gear on the way to the test, outside the test centre rev it hard for 5 seconds 2 or 3 times helps clean the exhaust out.

haha ehm, well i wouldnt do it :L

all thats being tested is your smoke content, unless theres a boost leak or shes an awfull rough engine, a good run would clear her out.

a good hard hot run to clear her out, followed by a steady drive at around 55 -60 mph under 3k revs for a few mile does the trick best imo.

reving her outside the test center is only clearing it out. no need for it after a good run.

angeldaisy

Ok as far as I know this is what has been done to the car so far
New lambda
New cat
Abs pump replaced

Is it going to be an expensive job to sort out these probs do you think - im beginning to wonder if its worth it!

jca

This is a petrol car so bogman advice like "rev her out laad" is not very helpful. It could be that the engine is badly worn and burning oil although I'd imagine the ppm figures would be much higher. Is it using much oil in normal use, what mileage is on the car?

harg90

angeldaisy wrote: »

Ok as far as I know this is what has been done to the car so far
New lambda
New cat
Abs pump replaced

Is it going to be an expensive job to sort out these probs do you think - im beginning to wonder if its worth it!

do you know was it a second hand genuine cat or a spurious?
and the abs pump has nothing to do with your emissions :L

its not looking great tho tbh.

harg90

jca wrote: »

This is a petrol car so bogman advice like "rev her out laad" is not very helpful. It could be that the engine is badly worn and burning oil although I'd imagine the ppm figures would be much higher. Is it using much oil in normal use, what mileage is on the car?

apologise if going slightly off topic and answering manmades question about a deisel confused you, and you may want to leave that high horse at the login page.

hc's at nearly 600 is fairly high tho? its nearly 3 times that of the pass limit

has your mechanic checked all breather pipes, plugs, air filter?

angeldaisy

the car is going back into the mechanic next week so he's going to check all of that out.

I just had a look at the first re-test that was done after the lambda senor was replaced and it is less than it was after the cat was fitted, so there has to be some kind of problem with that.

Anyway hopefully it will get sorted out next week

harg90

angeldaisy wrote: »

the car is going back into the mechanic next week so he's going to check all of that out.

I just had a look at the first re-test that was done after the lambda senor was replaced and it is less than it was after the cat was fitted, so there has to be some kind of problem with that.

Anyway hopefully it will get sorted out next week

find out if it was a spurious cat, and ask for a good second hand to be fitted.

jca

I can't see any cat being able to "clean up" those exhaust gasses, imagine what the gasses are like before the cat. Has the timing belt been done recently? Maybe the valve timing is out a tooth. Does it use oil and what is the fuel consumption like?

nct tester

those 1.6 engines are a disaster, valve stem oil seals give a good bit of trouble, which cause emissions problems. ive seen cars come in with 3 cats welded along the exhaust assembly and still fail because they are burning oil.

jca

Any progress op?

angeldaisy

jca wrote: »

Any progress op?

Im taking it to mechanic in the morning, hes a few ideas, so should know more tomorrow evening hopefully!

angeldaisy

Update: The mechanic had the car all day yesterday and worked out that it is the Lambda that's faulty - apparently he fitted a second hand one - so this is going to be returned to the place he got it from.
He is now going to fit a brand new lambda next week - reckons it should cost around 150e. hopefully this will do the job:rolleyes:

sebastianlieken

So he fitted a second hand lamda sensor. charges you for work done. Turns out the part he fitted is faulty. So now he's putting in a new one and charging you for the privelage of a job badly done first time round.

okaaayyy...

unless he only charged you for labour in the first instance and is only charging you for the part this time... e150 for a lamda sensor... maybe, but I wouldn't be a happy camper in if I were in your shoes.

clintondaly

I would change the mechanic before i would change anything else on the car.
When he carried out the other work did he not have the equipment to test the emissions before you did the retest ? seems like it would have been an obvious thing to do.

angeldaisy

the guy we use works from home, tends to charge a lot less labour than other mechanics which is why we use him. this is the first time in over 10 yrs of dealing with him that we have ever had a problem, so not too worried,

and rest assured I will be making sure that it is either fitted free or the cost of the other part & fitting is refunded.
my main problem is that its hubbie who deals with this guy and he wouldn't be the best at explaining things - tends to just accept what is told - unlike me who would be a bit more critical and cynical:rolleyes:

dh0011

most garages round myway dont have the equipment to test emissions