Failed NCT on Emissions

Murphman555

Hi, I was in for nct today with my 2000 golf mk4 and failed on emissions after doing a load of suspension work so I need to get it fixed rather than scrap it..the readings are, low idle (750rpm) CO 8.59 vol%, HC 553ppm ,High Idle, (3,340rpm) Lambda: 0.74, CO 8.67 vol%, HC 661ppm..any help would be great..

Special Circumstances

Is it guzzling fuel?

Murphman555

Special Circumstances wrote: »

Is it guzzling fuel?

No it's not bad on fuel..

jca

Is it burning oil? Those readings are shocking!! Is there a catalytic converter on the car?

Murphman555

It's putting out a small bit of smoke but not enough to choke you ( on tick over, not when driving) it has a cat but I don't know if it's gone. I noticed a pipe from the air filter to the back of the engine that looks like it's sucked in..!!!

hi_im_fil

It's running incredibly rich. Has the air filter been changed recently?

jca

hi_im_fil wrote: »

It's running incredibly rich. Has the air filter been changed recently?

With those readings the filter must be like a clinker:eek::eek:

kona

I'd put e100 on it being a 1.4

mullingar

Lambda of 0.74 and HC in the hundreds?

That's the worst I've ever heard

Its running extremely rich. Change the air filter, check the lambda sensor but I'd also wager if it's a 1.4 the valve oil seals are also gone as these engines are famous for blowing them.

jca

kona wrote: »

I'd put e100 on it being a 1.4

No sh*t Sherlock:):) A terrible engine. Probably needs a cat, valve guides and stem seals, new oil rings...ah feck it he needs a new engine..

kona

jca wrote: »

No sh*t Sherlock:):) A terrible engine. Probably needs a cat, valve guides and stem seals, new oil rings...ah feck it he needs a new engine..

Well I'd hardly put it on if i wasn't sure haha

Murphman555

Yes it's a 1.4... Maybe I should look for an engine..I thought I would get away with something small but it's not looking good...it was recently serviced aswell..

jca

Murphman555 wrote: »

Yes it's a 1.4... Maybe I should look for an engine..I thought I would get away with something small but it's not looking good...it was recently serviced aswell..

Don't mind us being so dramatic.. Start at the beginning by taking out the plugs and seeing is what colour they are. It could be one cylinder not firing or an injector continually leaking fuel into a cylinder. It has to be something fairly dramatic to give readings like that.

kona

I'd just buy a new car, it's got the car cancer. Probably work out cheaper too.

Murphman555

😜😜 I pulled a plug lead and there was oil in where the plug is..I will check all the plugs in the morning..is there anything else I can check..would it be worth putting something in the fuel to help clean the engine.?..

chocksaway

Id these results a few years ago and it turned out the oil rings needed replacing as it was burning a serious amount of oil:

Low idle (730rpm) Engine temp 80 degrees
CO 0.51 vol% above 0.50% fail
HC 436 ppm above 0 ppm fail


high idle (2,800 rpm)
Lambda: 0.91 not between 0.97 and 1.03 fail
CO 2.09 vol% above 0.30% fail
HC 1065ppm above 200 ppm fail

Unless you're really attached to the car I'd be getting rid of it

Murphman555

I can't afford to change it at the moment..

chocksaway

Murphman555 wrote: »

I can't afford to change it at the moment..

It cost me around 650 quid to get mine sorted. Which was insanity really cause that was all my car was worth. But i knew the service history and had put money into it getting it right so at the same time it was (kinda) worth it.

Im still driving around in it almost 4 years later

Murphman555

Holy sh*t, really.. I really don't know what to do..this could be the start of a lot of problems or the end of all of them...that's a lot of money....

kona

Murphman555 wrote: »

😜😜 I pulled a plug lead and there was oil in where the plug is..I will check all the plugs in the morning..is there anything else I can check..would it be worth putting something in the fuel to help clean the engine.?..

You need to pull out the actual spark plugs, oil around the lead is likely just messy servicing.

Just another thing, dip the oil, if it's using it there won't be much left.

Murphman555

The oil is in the first one on the left as you look down on the engine and the one on the far right....just dipped it and the oil is at the level..

Aenaes

You could try a bottle of Dipetane, costs about €10. It's helped us get a few things passed.

Murphman555

I will try it,thank you..

kona

Murphman555 wrote: »

The oil is in the first one on the left as you look down on the engine and the one on the far right....just dipped it and the oil is at the level..

Which level max or min?

Dipetane will not fix figures like that man, save the Tenner!

Murphman555

Max.

kona

Murphman555 wrote: »

Max.

Was it serviced recently?

Murphman555

Yes..last week.

magentis

Shes a gonner.Scrap it.Tbh it would cost €700 to 1k to get it to pass.

kona

Murphman555 wrote: »

Yes..last week.

It may have been over serviced and the rings can't handle the amount of oil.

Best thing to do is to get a compression test done, it won't be expensive and will tell you how wrecked the engine is. Get the oil level taken down to halfway between max n min. Probably about 300ml of oil.

If it's using oil either by being worn or by over servicing , the cat will not last long in those conditions , that's another expensive part you could do without crapping itself.

Murphman555

I have about €350 to €400 gone into the suspension and tyres and bits..I can't really afford to scrap it..

kona

Murphman555 wrote: »

I have about €350 to €400 gone into the suspension and tyres and bits..I can't really afford to scrap it..

It's not looking good tbh. Your other choice is take your chances without a nct.

The car will eventually give up and you'l be putting a awful lot of oil into it just to keep it going.

You'l get a few hundred on donedeal for it. You'd get a solid car with nct for 1,500 mark.

Murphman555

Holy crap..I was hoping that someone would say that it's this or that and it would be about a €100 fix..

Murphman555

Maybe,sure all they can do is take the car...just have no peace driving it..**** yourself every time you see a checkpoint..although I think Irish water workers have all the Garda contracted out at the moment..lol

kona

Murphman555 wrote: »

Holy crap..I was hoping that someone would say that it's this or that and it would be about a €100 fix..

These golfs are notorious. As I said get it to a garage and let a mechanic do a compression test .

Only then can you make a descision with all the facts.

Murphman555

Thanks krona, I will organise that..

Murphman555

Sorry kona, predictive txt..

vandriver

Murphman555 wrote: »

I have about €350 to €400 gone into the suspension and tyres and bits..I can't really afford to scrap it..

Look up the sunk cost fallacy.

George Dalton

It needs a rebuild. Will cost around €1000.

I know it is too late telling you this now but this is precisely why it is always best to bring an older car for NCT before spending any money on it.

Murphman555

Thanks guys...lesson learned...and thanks for all your advice too..

Will 1000 buy you a car that is in as good or better shape is the next question? I'm doing a form or bangernomics at the moment:

Car: 250 (back in 2012)
Engine rebuild (rings, bearings, timing chain, top end rebuild etc)/clutch and general tidying and overhaul: €1000+hours and hours (early 2013)

In two years following the rebuild I have needed following spent above regular servicing:
2 droplinks €30
Suspension bushings to replace crappy poly ones I foolishly used €150

The current aim is to keep on driving for 10 years/when something expensive breaks. If you splashed out for engine rebuild you could possibly get another 5-10 years from the car without spending anything futher.

Murphman555

For anyone who finds this....I found the problem in the end...There was a wire not properly pushed into the lambda sensor and when reconnected it brought the emissions down.

biko

Sound, thanks for the update.

Macker1

Rather that start a new thread I just added to this.

Car failed NCT today for emissions

07 Nissan Primera 1.6 petrol with 200k on clock

Here are the test results just wondering how bad they are, what issue are they indicating and what could be done to rectify issue.

Engine/Oil Temperature 100 c

Low Idle (860 rpm)

CO 11.11 vol% above 0.30 % is a fail FAIL/REFUSAL
HC 382 ppm

High Idle (2,800 rpm)

Lambda 0.71 not between 0.97 and 1.03 is a fail FAIL/REFUSAL
CO 10.75 vol% above 0.20 % is a fail FAIL/REFUSAL
HC 338 ppm above 200 ppm is a fail FAIL/REFUSAL


Car is looked after and serviced on a regular basis. This year I have bought new tyres and have had brakes, bushings and front shocks replaced. To be fair there has been an engine malfunction warning light intermittently on the dash Initially my mechanic thought this was related to a faulty oxygen sensor but has mentioned is may also be related to the catalytic converter.


Any helpful advice welcomed.

mullingar

Wow, they are very poor results and it's running extremely rich.

Get the lambda sensor changed and hope all the excessive HC (Hydrocarbons =unburned fuel) has not damaged your cat.

If the lambda sensor fixes the low idle emissions but then fails the high idle CO, the cat is dead. Much cheaper to replace the lambda sensor and throw it back into the NCT instead of also replacing the cat at the same timr

saabsaab

Glad you got a fix for it with the disconnected sensor. If it was rings/ worn valve seals , I saw an additive somewhere (Halfords/ebay) that said it could help recondition these buy adding to the oil. Probably a temp. solution but might be worth a try. You would be advised to put an additive in the fuel and change the air filter too while you are at it.

Macker1

mullingar wrote: »

Wow, they are very poor results and it's running extremely rich.

Get the lambda sensor changed and hope all the excessive HC (Hydrocarbons =unburned fuel) has not damaged your cat.

If the lambda sensor fixes the low idle emissions but then fails the high idle CO, the cat is dead. Much cheaper to replace the lambda sensor and throw it back into the NCT instead of also replacing the cat at the same timr

How much do you reckon I could be looking at for replace and fit of Lambda Sensor and if that doesn't resolve issue what would a new catalytic converter set me back for supply and fit. ??

jimgoose

That's bad, and I've seen a fairly bad one myself lately. That lamba figure would hint to me that it's not the cat, at least not primarily. You need to get it scanned for fault codes first. Is it burning oil? I'd also do the old paper-up-to-the-tailpipe trick to check for a burnt exhaust valve.

jca

jimgoose wrote: »

That's bad, and I've seen a fairly bad one myself lately. That lamba figure would hint to me that it's not the cat, at least not primarily. You need to get it scanned for fault codes first. Is it burning oil? I'd also do the old paper-up-to-the-tailpipe trick to check for a burnt exhaust valve.

What's the paper up to the tailpipe trick you mention? That's a new one on me.

Macker1

jimgoose wrote: »

That's bad, and I've seen a fairly bad one myself lately. That lamba figure would hint to me that it's not the cat, at least not primarily. You need to get it scanned for fault codes first. Is it burning oil? I'd also do the old paper-up-to-the-tailpipe trick to check for a burnt exhaust valve.

My usual mechanic had mentioned that the oxygen sensor appeared to have an issue and might have to be replaced. Really hope that this is the issue as replacing the catalytic converter is something I really could do without given the amount of money already spent on the car this year.

Any rough ideas on how much this should cost??

I think I'll get a couple of quotes for this and get the sensor done before going back to NCT.

I just tried the paper up to the exhaust and it appears to be fine with the paper consistently being blown away.

jimgoose

jca wrote: »

What's the paper up to the tailpipe trick you mention? That's a new one on me.

Sheet of light paper up to the tailpipe, about an inch or two away, with the engine running. It should be consistently blown away from the pipe. Any vacuum there would indicate a possible issue with an exhaust valve closing properly, usually because it's burnt.