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Help Interpret NCT Fail please

johnplayerblue

Car is a 1.4 16v 2000 Vw Golf AHW engine.

Went for my retest this week and failed on emissions. Again.

Work done before retest: New back & middle box, fuel line cleaner, engine flush, fresh gl of castrol magnatec 10w-40 new fuel/air/oil filter, four new NGK's.

Throttle body and EGR valve removed and cleaned along with air breather housing and oil separator. Anyone who owns an early mk4 petrol golf will know these last few steps are a twice a year job anyway.

As you will see from NCT report these steps made very little difference apart from the car running a little better, but she was running as I'd like her to be anyway.

At this stage Im thinking 3 things. I'm only going to mention One and hopefully you guys can help with the other two which are more than likely the cause.

It's only a little 1400cc but it really wasn't a cared for car, I have it 18mths and have been good to her and she to me.

She has 175k mls (Not a typo) but runs perfect, and i do mean perfect. I do about 600mls a week with her, 50% Dual carriage, 50% B Rds.

There is however a little oil in chambers 4 & 2 and needs cleaning once a week. Firing order is 1-3-4-2 if memory serves me.

I have done a compression test and indeed 4 & 2 are about 30% lower than on 1 & 2 but this is not a big issue as such as the cam carrier seal just needs doing which i hope to get done in the next week or so.

As i said I have the car 18mths and have put 40k mls of the 175 and she hasn't let me down once. I don't want to get rid of her as she's been good to me! You know how it is.

She's not burning or using that much oil, I top her up once a week but that's all it is, a top up with maybe a 1/3 of that been due to the cam seal so all in all I think the engine is good. That said..!
Nothing would give me greater pleasure than to give her a rebuild but I lack the expertise at the moment.

This to my mind leaves just two other causes, so hopefully one of you guys can throw an expert/experienced eye at the NCT reports and tell me where else my precious needs me to spend on her?

P.s. No suggestions about selling or scraping pls as you just don't do them things to a loyal servant! and especially to a Golf. Sorry if that pisses you VW haters off ...

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biko

You can try the advice from http://type2.com/s/?tag=exhaust

Check the Mixture and Ignition Timing. Especially on VWs, over advance timing will cause high CO readings. When setting up ignition timing, mixture, and idle speed, follow the book.

On Digijet Vanagons, disconnect and bypass the Idle Stabilizer when setting the timing and idle speed. Resist the temptation to “advance” the timing for performance.
Also make sure both the vacuum and mechanical advance mechanisms are working properly. On Digifant Vans, Disconnect the Temperature Sensor before setting the timing. Again, resist the urge to over advance the timing. Check the O2 sensor system to ensure it is working properly. Resist the urge to adjust the Airflow box.
If the O2 sensor system is working properly, it will compensate unless some one has already made a mess of things. Also check the oil, diluted oil will also cause high CO readings.
Worn rings and valve guides will contribute to this also. However this will only be a problem on very tired engines. Setting the idle speed around 1000 rpm will also help keep the CO readings down.

High carbon monoxide (CO) emissions are a telltale sign of a rich fuel mixture. On older carbureted vehicles, fuel-saturated plastic floats, incorrect float settings, leaky power valves and misadjusted chokes are often responsible for the rich mixture. On newer vehicles with feedback fuel controls and fuel injection, leaky injectors, excessive fuel pressure and sluggish or contaminated O2 sensors are all possibilities to investigate.

shanemc1

Plugs filling with oil is a separate gasket issue (Although not a help). The big problem you have is the compression. More often than not it's worn piston rings in that VW engine. To check this remove all plugs, have somebody keep throttle wide open, put 3 or 4 table spoons of engine oil in each cylinder right before you turn the engine over (Make sure you do a separate clean test before this and write down figures). If the compression rises this means worn rings. Unfortunately what I have also encountered with Golfs is that due to this the catalytic converter is also damaged. Your emissions problem is down to the compression issue.

itarumaa

I think that since the car is consuming so much oil, it shows up in the HC value,

btw that idle speed HC value is really bad, I had long time a go an old Peugeot 205 1.4l petrol car with carburetor and it took about 1l oil / 1000km and values were similar. For modern petrol car those kind of results are really bad.

Atomic Pineapple

I mean this in the nicest possible way.....

...its a 00 1.4 Golf with 175k miles on the clock and is well past its best days according to those readings, You can still scrap, sale, give it away and be a VW fan boy.

Its the perfect excuse to move on to a GTI

johnplayerblue

draffodx wrote: »

I mean this in the nicest possible way.....

...its a 00 1.4 Golf with 175k miles on the clock and is well past its best days according to those readings, You can still scrap, sale, give it away and be a VW fan boy.

Its the perfect excuse to move on to a GTI

(VW fan boy) Really wish i hadn't used that term..:rolleyes:

Ye I know, I looooong for a MK6 GTI, really not gone on the body/look of the MK5 but know it to be a fantastic car.

But the thing is, the more I read the replies about worn rings the more I just want to rebuild. Kinda sick I know but with some TLC, a little money and plenty of time I think I really can get ALL of the 75hp back into her:D

Have a feeling she would look something like these picture when she undressed.

Mr Benevolent

johnplayerblue wrote: »

Have a feeling she would look something like these picture when she undressed.

Jebus that's bad! Unless you have a big emotional attachment to this car I'd really run away.

johnplayerblue

Confab wrote: »

Jebus that's bad! Unless you have a big emotional attachment to this car I'd really run away.

and those pictures are from guess what...? Thats right!
A 1.4 00 16v AHW that failed something terrible on emissions but a weekend diy mechanic rebuilt and brought it back to life so theres hope for me. Maybe!

I could take the easy route and replace the CC & or Lambda and still fail, where as this way i'd get a few more years and maybe even make it to 300k mark which for a 1.4 16v of that year would surely be a world first.

2yung2adm

The greatest cause of co problems are the spark plugs. make sure that the plugs are getting enough spark and that the gaps are correct. I think it will solve your problem provided there is not a glaring oversight such as a leak in the air intake on the inlet side after the sensors. High co is basically unburned or incorrectly burned fuel.

kasper

do the compression test and then retest with oil in the bores if its the rings pull the head off sump off pull out the pistons fit oversize rings hone out the bore reassemble drive her on

nmacc

I had a similar problem with an 8V Bora. Turned out the Lambda sensor was filling with "oil". The diagnosis was: "Scrap it, the engine is fcuked"

Not so; it was actually oily water. A slight head gasket leak.

No rebore required in my case, just new gasket.

itarumaa

if that golf would be my car I would go trough the basics and see does it make any difference,

-air filter
-spark plugs
-measure the oxygen sensor
-check error codes (inc. maf if possible)
-oil change
-is there any air leaks

HC value should be caused by lack of compression / oil consumption, but it should not show up in the co value. If you would do the tasks by yourself, it should not take too much money.

good luck,op.

CarMuppet

Ok so your emissions were as follows:

TEST 1:
@Idle CO 0.56
@Idle HC 283
@Rev CO 0.81
@Rev HC 221
Lamda 1.05

SERVICE OF CAR

TEST 2:
@Idle CO 0.52
@Idle HC 211
@Rev CO 0.85
@Rev HC 156
Lamda 1.02

Couple of points:
A 30% lower compression on 2 cylinders is not doing you any favours... this is venting somewhere... if you're toping up oil then you're looking a head gasket failure not just a rocker-cover/cam-seal problem or cylinder wall or pistion rings. What compression values are you seeing in the bad cylinders? Less than 80psi? Burning oil will effect HC values. If you put some oil in the cylinders deliberately and repeat the compression test does it improve the values?

Assuming the engine was compressive-intact the high HC/CO would indicate either over fuelling or incomplete burn-cycle. Incomplete burn is caused by one of the following:
- Low output voltage from coil or coil-pack
- Bad/broken high tension cables.
- Bad/broken disty (don't know if this car has coilpack or an old disty)
- Wrong plugs or wrong plug gaps.

Of course all these emission problems might be caused simply by oil fouling the plugs (due to gasket or cylinder wall damage) then killing the spark during a given cycle. If you put in new plugs (or cleaned plugs) then run the car for say 5 miles... remove the plugs.. what do they look like? Are they only fouled in two cylinders (the low compression ones) or all four?

Worse case there is a problem with the head, ie exhaust valve(s). Sorry can't be more helpful.. but please do let us know how you're getting on...

EDIT: What does the breather pipe look like? Is it gummed up with black oil or yellow 'mayonaise'?

Best of luck!

galwaytt

...the gap you need to bridge is beyond that of servicing: fundamentally, your bores are worn/rings shot.

Anymore than 10% compression difference really is time for surgery I'm afraid.......

johnplayerblue

galwaytt wrote: »

...the gap you need to bridge is beyond that of servicing: fundamentally, your bores are worn/rings shot.

Anymore than 10% compression difference really is time for surgery I'm afraid.......

You sir have just made me smile. Nurse! 6mm 12point spline drive please.

JHMEG

Catalytic converter?

johnplayerblue

JHMEG wrote: »

Catalytic converter?

Catalytic converter & or Lambda have a big part to play in this but I really feel that doing this and perhaps passing the NCT is just a quick temporary fix and the underlining issue will just come back and bite me on the ass and a new cc will end up been ruined very quickly.

Its counter intuitive to start taking something apart that, at the moment is running fine but I think this is a start from the inside and work my way out solution.

2yung2adm

If you have not changed or set the gaps in your plugs do it now before the more expensive items. wrong plugs and wrongly gapped plugs are a major cause of high CO

johnplayerblue

2yung2adm wrote: »

If you have not changed or set the gaps in your plugs do it now before the more expensive items. wrong plugs and wrongly gapped plugs are a major cause of high CO

Wait, wait, wait! When I bought the car it had 4 multi-electrode NGK's

When I went to my motor factor and asked for 4 NGk's for a 00 1.4 16v AHW engine I was automatically give the multi-electrode type and so when I was reading through this thread I just kind of skimmed over the plug thing but it just keeps getting mentioned.

Just did a search and anywhere that I have so far checked seem to be selling only the single electrode plug for the AHW engine.

Am I running the wrong plugs all this time...!

CarMuppet

johnplayerblue wrote: »

Am I running the wrong plugs all this time...:eek:

Possibly... also plugs don't just provide spark.. they transfer heat away from your cylinder too.

What compression values are you getting for the 4 cylinders in PSI?

johnplayerblue

CarMuppet wrote: »

Possibly... also plugs don't just provide spark.. they transfer heat away from your cylinder too.

What compression values are you getting for the 4 cylinders in PSI?

I can't find my dam note book! Gona have to run the test again! Dam it, ill be back with the readings in psi soon!

Just called Bradshaws, my motor factor and they said No I have the right plugs. He also recommended using a bottle of Dip-Tech, I think thats what he called it.

I have used Pro-Tec for cleaning the fuel system but he sounded quiet sure Dip-Tech would soon solve high CO

shanemc1

Take it from a professional, if there is a 30% difference in cylinder compression this is were the issue is. No €10 bottle of magical wizard piss from a motor factor will sort this. As was already said major surgery is required because it is serious.

johnplayerblue

Thanks for the help so far lads! Sorry about the delay in posting!

OK, It seems I had a faulty compression tester! brought it back this morning and had it replaced, looks like someone else had brought it back before me and it ended back up on the for sale rack.

So, Ive done a new test and things look very normal and healthy, even for 175k mls, well depending on what the readings should be. Can't find what a normal reading should be for this engine!

From left to right, Chambers 1-3-4-2 the readings are!

Exactly 230psi or 16bar. Just to be extra sure I did them again after 20mls more driving and the EXACT same results right across all 4 chambers. There goes my reason for a rebuild.

Also, whilst I was in the factors I bought a HT tester and all four HT leads are firing perfect. Its a static ignition system on this engine.

So at this stage I'm thinking Cat/Lambda OR as one of the lads said earlier about incorrect fuel mixture but the plugs are brownish, light gray and so I think mixture MIGHT be ok!

I've posted some pictures of the plugs which I've Double checked and they are the correct plugs after all and to the untrained eye they look in pretty good shape?

My dam copy of VCDS won't allow me access the engine module to see if theres any DTC codes but I've never had an engine management light, Airbag/SRS yes, but no engine management light.

Managed to get in to the Engine controller module, These are the results but I think they are the result of the compression test or just old codes in memory as its my first time to access the module. Car starts and runs perfect!

Address 01: Engine Labels: 036-906-014-AHW.LBL
Controller: 036 906 014 AN Component: MARELLI 4CV
2893 Coding: 00031 Shop #: WSC 00028 6 Faults Found

01249 - Fuel Injector for Cylinder 1 (N30)
26-10 - Output Open - Intermittent

01250 - Fuel Injector for Cylinder 2 (N31)
26-10 - Output Open - Intermittent

01251 - Fuel Injector for Cylinder 3 (N32)
26-10 - Output Open - Intermittent

01252 - Fuel Injector for Cylinder 4 (N33)
26-10 - Output Open - Intermittent

00609 - Ignition Output 1
26-10 - Output Open - Intermittent

00610 - Ignition Output 2
26-10 - Output Open - Intermittent
Readiness: N/A

Esel

Good news on the compression!

itarumaa

It is really nice to see someone actually doing some effort with the car and not just give up, so well done johnplayerblue.

I think the next step would be measure the lambda, you can find instructions from the internet, then you would know does it do its job like it should without spending much money,

have you actually calculated, how much oil the car is using, lets say in 1000km?

1l, 0.5l or something else?

johnplayerblue

itarumaa wrote: »

It is really nice to see someone actually doing some effort with the car and not just give up, so well done johnplayerblue.

I think the next step would be measure the lambda, you can find instructions from the internet, then you would know does it do its job like it should without spending much money,

have you actually calculated, how much oil the car is using, lets say in 1000km?

1l, 0.5l or something else?

Hey! I'll get my Multimeter out, run her up on the ramps and test the Lambda.

She uses about 1/4 of a pint of oil after say 1k Mls.

Oil & filter changed every 6/7k Mls and given the very poorly thought out design of the oil separator and air breather housing I change the air filter perhaps twice a year.

I flushed out the cooling system a year ago, filled with a 50/50 mix and haven't had to put a drop of water/coolant in since.

Again, thanks for the help lads! I'm really learning how to diagnose here and that just leads to better self sufficiency which is alright with me.

Did you read the thread here about €1200 for a T/belt & water pump for a Fiesta I think it was?
I didn't respond to the post as I would surely have goten a ban for giving my thoughts on that one!

Anyway, looks like the last two hurdles for me are Lambda or Cat, hope its not Lambda & Cat.

[Deleted User]

Well done on the work so far

Out of curiousity have you tried any VAG forums ?

johnplayerblue

RoverJames wrote: »

Well done on the work so far
Out of curiousity have you tried any VAG forums ?

James, When you've owned Four golfs theres not a vag site from here to the USA, UK, South Africa and most every where else in between that your not a member off but I always find myself back on Board's. Maybe the lads here should do like the guys over in broadband have done with midband and start a sub forum for VAG.
Postings would drop by a 1/3 over night on the main motor forum.

Come to think of it, After Four golfs you'd have thought I'd know better...:rolleyes:

[Deleted User]

johnplayerblue wrote: »

James, When you've owned Four golfs theres not a vag site from here to the USA, UK, South Africa and most every where else in between that your not a member off.

Come to think of it, after Four golfs you'd have thought I'd know better...:rolleyes:

Fair play

Perhaps editing the thread title may get more folks in the know posting, or if you haven't yet a thread in the tech help forum here may be worth a shot. Lots of very knowledgable dudes post in there.

ttm

Maybe a dumb question but do you actually have a CAT? I know you've got a box on the exhaust system that is supposed to be a catalytic converter but is there anything in it? I had problems on my old ford and knocked the catalyst matrix out of it to keep me going when it got blocked and replaced the box for the NCT. Don't know if the VAG CATs suffer from the same problem as the fords but its worth checking if you can get the CAT off easy enough. With a gutted CAT the exhaust note might be a bit rougher which could be an indication of that being part of the problem.

2yung2adm

any update on this issue.
A friend of mine went for a test with a merc. It failed miserably on the co test. He changed the plugs and that improved the reading cutting them by 50% but it was way over the top still.
He was told that non oe lamda sensors simply will not do for the test on mercs and that it is true for other German cars.
He swapped it with an oe sensor off another merc and flew through the test.