NCT emission fail

Guest193

Car: Seat Cordoba 1.2 petrol, 2005, 115 000 miles on the clock.


Hi I failed the emission test today. The datails below:


Low Idle CO 0.43%, Above 0.30% FAIL


Lambda : 1.03,limits : 0.97/1.03, PASS

High Idle (2,826 rpm) CO 1.25 %, Above 0.20 % FAIL
HC 99ppm, limits: fail if above 200ppm PASS


Have air filter changed, new plugs, oil and filter changed arround 3,500 miles ago.

The car is burning oil, depends how I drive, could be 500ml per 1000km, but if I drive on motorways and long journeys is 1L per 1000km. Probably this is the issue? Heard many opinions that cars with blue smoke passed NCT that 1L/1000km is not much etc. Don't know what to do, car passed everything else fine, suspension, brakes like new, don't want to scrapp it. How much would it be for engine renovation? probably the rings are worn, because it burns oil while accelerating, never noticed any blue smoke...

Maybe use some lucas oil? it will probably just thicker the oil, Im using 10w40 for top ups.

I used some depatine for few days, stopped using it 3 days before as I was adviced not to have it in the system. Today before the test I drove it very hard for about 40 minutes on high revs.

thanks for any advices

BOSTIK

The HC numbers on high idle don't look so bad, I'd say the catalytic converter is banjoed due to oil contamination.

Renegade Mechanic

I wish the NCT gave Oxygen results along with the rest of the gasses.
No oxygen at all? Catalyst is working at full pelt, problem is further up.
Lots of oxygen? Catalyst is goosed...


Also, re: oil burning, lucas oil additive is the one additive that actually helps, it's well worth putting it in with oil before a test.

jimgoose

My educated guess would be a shot cat converter, due mainly to my experience with initially contradictory-looking CO and Lambda readings.

Gravelly

VAG cars have a bit of a reputation for failing the emissions test due to failing or failed cats caused by oil contamination - there are conflicting theories as to whether the cats are more susceptible than other makes to failure due to oil contamination, or whether VAGs put more oil into them than other makes. In our garage the usual cure is to weld in the cat from a Toyota - they always seem to do better in the emissions tests with a Toyota cat, and they seem to last longer.

Guest193

I've put some Lucas oil today, will put a bit more dipetane day before the test. Is it safe to put like half bottle? I know the recommendation are 10ml per 10L petrol, but heard from people if you really want it to work you need to put half of the bottle and drive it hard. Know I guy who put 5e petrol with bottle of dipetane and passed, haha, this seems mad but worked. And do you think red ex or other petrol cleaner would be better ? or dipetane is really nr 1.

Question abaout high revs before the test, maybe in my case (car burning oil) I would be better off with driving at normal revs before the test arround 2500 ? before last test i was driving very hard at 2nd and 3rd gears.


My mechanic said that VW engines are like that, like the post above, he said cat may work bad with this oil, hopefully lucas oil will improve it.

And putting cat from toyotas seems interesting, but this only for the test? and then back to the old cat?

Gravelly

Guest193 wrote: »

And putting cat from toyotas seems interesting, but this only for the test? and then back to the old cat?

No, permanently. Once they are on a Toyota cat, they seem to pass the tests quite happily, regardless of oil contamination.

w211

How high are the idle rpm? It must be around 900, little bit less or more. For me it looks the the vacuum leaks, because high RPM are better result. Because it is so, it can be very big leak. I already commented it before on other post, how to find the vacuum leak.
If you have a access to scanner, you should look the live data.

EDIT: Do not mess with oil. That way you can destroy the engine. The oil channels can clog up easily. By the way, are you ever check the engine from under? The oil can leak out from seals. 05 car seals may not anymore so good and need to replaced.

EDIT2: There is my story how to find a vacuum leak (somewhere) https://www.boards.ie/vbulletin/showpost.php?p=109198101&postcount=15

Guest193

Low idle was rpm 807.

HC at low idle was 38ppm but it says N/A.

My oil sump seal was changed 2 months ago, it's dry everywhere. Not even one drop on the floor, my driveway is grey color so i would see. Engine rpm stays the same so according to your post on the link there is no vacum leak.

Another thing, I think my battery is going dead, sometimes i have the power steering light on, then have to restart the car so this light is gone, my mechanic said it's because of the weak battery and power steer requires lots energy, after long journey it never happens, usually on the cold mornings. But this probably has nothing to do with emissions? I'm amateur aboud the cars so just asking.

I had my car plugged in into computer and no codes there, only the bad coil was there but changed already.

And asking again, add a lot of dipetane before the test? or because of burning oil it won't help a lot. Talking about messing with oil, all people say this lucas oil is safe enough but won't be adding to much.., ive put a little bit just to see if it improves something. Heard about mobil 1 oil 10w60 or something it's so expensive but they said for worn engine it may help.

thanks.

Renegade Mechanic

Guest193 wrote: »

I had my car plugged in into computer and no codes there, only the bad coil was there but changed already.

Wait, ****....
Emissions fail..
VAG 1.2 three cylinder..
Repeat code for bad ignition coil..

Was it the number three coil by any chance? I may have some woeful news for you

That engine is notorious for burning away the exhaust valve in cylinder no. three.. Generally it happens over time, the lower compression throws unburned (and burning) fuel at the catalyst, damaging it.

Eventually you get more and more "coil" faults as the exhaust valve fails completely and eventually a mechanic does a compression test only to find 200psi in 1 and 2, and 70 psi in 3....

Engine comes apart for a full head overhaul and all is merry until the already damaged catalyst gives up the ghost altogether.

Sometimes, the cat gives up before the fault is realised.

OP, I'd get a compression test done

w211

Internal leaks are almost impossible to test. Oil can leaks out because the bad/broken oil rings, the head gasket are blown or the valves seals are bad. The oil can leak even to the cooling system trough blown cylinder head gasket. 500ml per 1000km, not sure the cooling system can handle such amount, sounds too much. The coolant colour should be what ever colour it was originally. One question, did you or previous owner made a flush? Typically it ends by oil drinking engine. Never flush until you used the right oil and replaced it by right interval.

The scanner live data are necessary to see the short term/long term fuel trims, O2 sensor(s) and more. These are the most important because it shows the engine run too rich or lean. O2 sensor(s) needs to switching between specific range. The live data can show the direction but the final repair, sometimes it can be a nightmare. There is so many things what is related by each other.

EDIT: Like a renegade says, there can be a well know problem for specific car make, model, year. I suggest 1 more thing. If you make the relative compression test, please make the leak down test too. At least for lower compression cylinder(s).

EDIT 2: Because you would like to prevent the situation like one of our member had. He/she discovered it and "saved the money" https://www.boards.ie/vbulletin/showthread.php?p=109200315
Ok too flat joke, sorry.

Guest193

unfortunately it was coil nr 3.... this coil only lasted 3 months, it was bought in the local shop, thought maybe it went down due to cheap part but now what you saying could be a problem.

The problem with coil was that suddenly the car started to loosing power and engine light was flashing for few seconds. Then it was alright for a week and then problem again so I changed that coil. If I knew I wouldn't buy this engine, just got this car in August. Thought VW are best cars, probably not polo engines... Any advice? pass the NCT if possible and sell the car? is there any permament fix for this cylinder?

I will ask my mechanic to check the compression next time I see him. Other than that, the car drives ok, takes no petrol, so cheap to run, and it's a good power even with this small engine, f** insurance in this country is too high, it's my 1st year on full licence, and 1.4 engines were so high price even through insurance broker.

Talking about the coolant level, it's the same since i got the car, same pink color.

So cat is probably f*** now, need to get the new one, I saw online some cheap new ones for 140e, but I don't know if it would be better the get the oryginal one from scrapp yard but that car could have same issue as mine.

Renegade Mechanic

No need to panic just yet, a compression test will take minutes.
But I've removed the heads from three or four cars over the last 12 years, though none in the last 6.. I think...
I know two were polos, can't quite recall the others.. And I'm not even a VAG mechanic

Renegade Mechanic

Soooooo...?

Guest193

Another go and another fail...

Have new cat and new spark plugs.

reading from today:

low idle 0.14% passed

high idle lambda 0.97 pass

CO 2.22% fail
HC 130 pass

so first test lambda was lean 1.03, then at second go 0.96 now 0.97. So from lean to rich haha. Have enough already, especially with new cat, with the old cat the high idle was 1.2 now 2.22, crazy... low idle perfect but so what. Don't understand this car at all. My mechanic will be trying to get is sorted he got the emission equipment so we will see.

My question is why is it going rich? the air filter is clean changed 6 weeks ago, I checked it few days ago and looks like new. I put new spark plugs 2 days ago, car is driving perfect, no misfireing, easy idle, good acceleration, has power and everything.

Could it be exhaust leak? going mad, some countries are not even tested for emission on the car tests., on my town a fuc... factories pollut like mad but the goverment watch us drivers to have perfect emission, no sense at all !

just to let yous know, cat is new not second hand, it was cheap though but don't understand why the old one had better co high reading. Could it be a faulty lambda? on the test the readings were going mad, jumping like from 0 to 2 it went to below 0.2 for few second which is the pass mark, i wish it was just the lambda sensor fault....

w211

Leaky injectors?
Bad MAF?
Bad temperature sensor?
Bad fuel pressure regulator(too high pressure)?
O2 sernsor(s) readings?

It is hard to guessing if you can not present the live data readings.
You need a mechanic with obd2 scanner, what are able to read the live data.

There is not too many things left why it goes rich. So the old cat was good, you still have it?

Renegade Mechanic

Hardly... Hardly did a new spark plug go in with a pinched electrode....



See that gap at the bottom? Exactly one hacksaw blade should neatly fit there..

w211

Renegade Mechanic wrote: »

Hardly... Hardly did a new spark plug go in with a pinched electrode....



See that gap at the bottom? Exactly one hacksaw blade should neatly fit there..

There was not misfire like a Guest193 said. No misfire, no spark plug problem

Renegade Mechanic

w211 wrote: »

There was not misfire like a Guest193 said. No misfire, no spark plug problem

CO isn't unburbed fuel, its poorly burned fuel. Incomplete combustion. If a spark plugs gap was too small, the resulting spark would still ignite enough of a punch to push a piston, but it would do so poorly. Not poorly enough to miss-fire as it's still technically firing.

Without a full emissions analysis it's more of an "educated guess", but still one worth entertaining, given that compression has been ruled out as a possibility.

w211

Here is all guessing. Even Guest193 was guessing and replaced the cat. This is expensive guessing. It was possible to avoid but who ever made that call did not understand anything about the live data. Yes it is hard to read and very easily can make a mistakes. The cat is very easy to test, use the infrared thermometer.

Renegade Mechanic

w211 wrote: »

Here is all guessing. Even Guest193 was guessing and replaced the cat. This is expensive guessing. It was possible to avoid but who ever made that call did not understand anything about the live data. Yes it is hard to read and very easily can make a mistakes. The cat is very easy to test, use the infrared thermometer.

Aye, but this guess is free. Just take out the spark plugs and look
And thermometer is good at showing cat that has failed or a cat that has gone red. Not so much a cat in between those stages.

com1

I am surprised nobody has mentioned the italian tune up. I put a 1.4 golf through a few weeks ago and it failed with pretty much the exact same figures. On the way to the next test i tooled down a motorway at high revs (120kph @4500rpm for about 20 minutes then into the test. CO emissions dropped to 0.

Guest193

Thanks for all the advices.

Spark plugs are fine I think, the gap is as on the picture, these are denso spark plugs I paid 20e for 3, before i had triple electore ones in, same company but in the shop they said electored doesn't matters while my mechanic adviced to have this 1 electorde like on the picture.

About the cat, my mech said it was very bad, it had a hole in it, he showed me the old cat the inside looked completely like a mess.

About the tune up, i don't think it would help in my case, i murdered the card yesterday on low gears with dipetane in it, the reading went a bit down because my 2nd attempt the readings were worst than yesterday, so CO went down from 2,75 to 2,22. HC from 240 to 130, low idle from 0.23 to 0.14, but still not enough.

It's wierd but this lambda is the thing that bothers me too much, 1st attempt it was 1.03 so lean, and then went to rich. it's like after the new cat it went rich, but probably nothing to do with it.
We will see what my mech figure out today.

About this live data, how much is it for that? and does it says what are the problems? do they need to do it couple of times or just once is enough? I don't think my mechanic has one.

My knowledge about the cars is not too high, but why there is such a big difference on low and high idle? low idle 0.14 so going rich doesnt matter for the low idle because engine is not under pressure?.

w211

The live data is possible to save the frame by frame. For your case there is important to save rpm, short term fuel trim, long term fuel trim and all O2 sensors. After that you car need a test drive and all that data be saved to the scanner. The good scanner can save it as pdf file and it is easy to share. You have a interesting mechanic if he did not made that type of test on first time.

The short term fuel trim and the long term fuel trim must equalize each other and can not be higher than 10%. O2 sensors must switching on specific range. The test must made my warm engine (fuel system status - closed loop). Can not ignore the other sensors readings too but these are easier to monitor.

zilog_jones

Renegade Mechanic wrote: »

...given that compression has been ruled out as a possibility.

But we never saw results of a compression test...

Guest193

My mech made the compression he said it was ok. I have to push him harder because if he thinks he is good needs to find a way for this, and this live data seems esential...

w211

Ask the pdf file to e-mail and we all will analyze it here The good scanner have a option to send the test file to your e-mail.

I can offer that live data readings for you free (it is not advertising because it is free help). We all like to know what was the real problem.

Does ne1 know?

2007 Mini One failed on emissions today. Any quick fix to get through retest? Attached report from NCT