NCT Emissions Fail Help! 1.4 VW

selfdiy

Hi All,
Failed the NCT this morning, only thing wrong is emissions.

2000 1.4 VW Golf.

Had changed, oil, plugs and air filter just before. Also treated it to a bottle of Diptane.

Failed on high idle (2850 rpm).

Lambda was 1.09. -- Greater then 1.03 is a fail.
CO 0.66%. -- Greater the 0.30% is a fail.
HC 399 ppm. -- Greater then 200 is a fail.

Any advice suggestions welcome?

Thanks in advance.

ION08

these 1.4's are notorious for failing the emissions test.

Is it burning any oil? What's the mileage on it?

selfdiy

ION08 wrote: »

these 1.4's are notorious for failing the emissions test.

Is it burning any oil? What's the mileage on it?

There is a 115,000 miles on it.

I think the likely problem is the valve stem seals, there is a little smoke on hard acceleration.

I believe they can be done with the head on. Do you know if its a difficult job?

But I think I've decided to sell it.

Alanstrainor

selfdiy wrote: »

There is a 115,000 miles on it.

I think the likely problem is the valve stem seals, there is a little smoke on hard acceleration.

I believe they can be done with the head on. Do you know if its a difficult job?

But I think I've decided to sell it.

I can't imagine that being an easy job. But i've never done it so I just don't know!

The cars not worth very much even with the NCT, so that would be the biggest consideration really.

jca

selfdiy wrote: »

There is a 115,000 miles on it.

I think the likely problem is the valve stem seals, there is a little smoke on hard acceleration.

I believe they can be done with the head on. Do you know if its a difficult job?

But I think I've decided to sell it.

Smoking on acceleration is piston ring/bore wear. Valve stem seals shows as smoke after prolonged idling or smoke on acceleration after a long descent on a closed throttle.

selfdiy

jca wrote: »

Smoking on acceleration is piston ring/bore wear. Valve stem seals shows as smoke after prolonged idling or smoke on acceleration after a long descent on a closed throttle.

It really only does it in morning, when taking off for the first time. I guess some sort of compression test would tell which.

Notch000

diptane

selfdiy

Notch000 wrote: »

diptane

Had a litre of that in it. Had put it in over several days, started last Saturday.

Don't think it makes much of a difference, maybe if your injectors were dirty, it would.

The Mulk

Yeah Dipetane had no effect on my 02 Mondeo's high emmisions, I've heard you can get some oil stabiliser or change the grade of oil and it might reduce the emissions.
I don't know whether this is the same stuff http://www.amazon.co.uk/Lucas-Heavy-Duty-Oil-Stabilizer/dp/B000AS1XYO
I just sold mine for a couple of 100 as it was time to let it go and I didn't wnat to start putting money into it.

blackbox

selfdiy wrote: »

Failed on high idle (2850 rpm).

Lambda was 1.09. -- Greater then 1.03 is a fail.
CO 0.66%. -- Greater the 0.30% is a fail.
HC 399 ppm. -- Greater then 200 is a fail.

These are unusual results. The High CO and high HC suggest too rich or burning oil. However the high lambda indicates too much oxygen in the exhaust (i.e. too lean). It could be a problem with a leak allowing air into the exhaust before the lambda sensor. The ECU would then think it was too lean and increase the fuel in the mixture (giving higher HC and CO than the cat can cope with).

I guess it could also be a combination of a faulty lambda probe and a faulty cat.

selfdiy

blackbox wrote: »

These are unusual results. The High CO and high HC suggest too rich or burning oil. However the high lambda indicates too much oxygen in the exhaust (i.e. too lean). It could be a problem with a leak allowing air into the exhaust before the lambda sensor. The ECU would then think it was too lean and increase the fuel in the mixture (giving higher HC and CO than the cat can cope with).

I guess it could also be a combination of a faulty lambda probe and a faulty cat.

Probably the first thing todo is get someone to read the diagnostics.

Then probably a compression test.

JamboMac

Your egr valve may not be working also, this re-circulates emissions back through the engine before finally going out the exhaust. Have the same car and have replaced both lambdas the egr and the throttle body needed cleaning.

selfdiy

JamboMac wrote: »

Your egr valve may not be working also, this re-circulates emissions back through the engine before finally going out the exhaust. Have the same car and have replaced both lambdas the egr and the throttle body needed cleaning.

Having done some more research, I'm leaning more towards what BlackBox and yourself suggest. This could be more todo with faulty sensors and cats then the little bit of oil it might burn.

selfdiy

I did a compression test on it today

#1 200 psi
#2 205 psi
#3 205 psi
#4 185 psi

My Manual states that the minimum is 7 bar (101 psi)
And the maximum difference between cylinders is 3 bar (43 psi)

So it seems from a compression point of view all is good.

I've taken a picture of the spark plugs... are these good or bad?

I think its likely running way too rich.