MOT Failure on Emissions/Water in Fuel

Post by **Kilgore** » 14 May 2008, 15:30

Hi All

Just popped the van in today for its annual MOT and as well as a few minor things it failed on hydrocarbon emissions. The engine was running a little rough but this was I thought due to the tappets having drained of oil and the van having been laid up for the Winter.

The van made a steady improvement after 20 mins or so of driving. I put 20 litres in the tank and have not driven it in the rain. The tank was quite low when I topped it up so I'm not sure how the water would get in as its been dry since. I've been told the water may be getting in through the worn filler neck. They are recommending changing the fuel tank at the same time as the filler neck but this will add ££££'s to the bill.

It still sounds like a tappet to me or a sticky valve. Anyone else heard of this or has had the same problem.

Thanks

Post by **ginge** » 14 May 2008, 15:33

what year is the camper

Post by **ginge** » 14 May 2008, 15:34

ohhps just seen that i thought it was just a visuale check or done on tick over will have to consult the book to be sure

Post by **toomanytoys** » 14 May 2008, 15:58

Filler neck rubber or if its a steel filler tube then you are in a spot.. the steel ones are not available and so the tank has to be changed apparently...

If the tank is ok and the filler tube ok, just the rubbers and hoses need changing.. change the fuel filter too..
Oil and filter change and use 20w50..
hydrocarbons could be down to co screw, poor combustion (valve rattle would have to be quite bad, but even so it measn the valves are shutting) and dirty air filter..

Oil and filter, air filter take it up the bypass full throttle, plenty of revs, through the gears and 70 mph...... before taking it in...

Post by **Kilgore** » 14 May 2008, 16:02

Just a thought.

I am also toying with getting the van gassed so if this is the genuine problem would I be better off just replacing the filler neck (to prevent any further water contamination) and putting the tank money towards the conversion??

Post by **Kilgore** » 14 May 2008, 16:09

toomanytoys wrote:Filler neck rubber or if its a steel filler tube then you are in a spot.. the steel ones are not available and so the tank has to be changed apparently...

If the tank is ok and the filler tube ok, just the rubbers and hoses need changing.. change the fuel filter too..
Oil and filter change and use 20w50..
hydrocarbons could be down to co screw, poor combustion (valve rattle would have to be quite bad, but even so it measn the valves are shutting) and dirty air filter..

Oil and filter, air filter take it up the bypass full throttle, plenty of revs, through the gears and 70 mph...... before taking it in...

Yep I think its the filler neck hence them needing to want to change the tank. Air filter was a bit dirty. The van has only been started up a few times in the last 6 months so I was just a bit dubious about the water contamination theory. Thanks for your ideas so far.

Post by **ginge** » 14 May 2008, 16:10

the limits on age related are co-4.5 hc-1200ppm and carried out on tickover

Post by **..lee..** » 14 May 2008, 19:00

Note: If a vehicle meets the CO requirement at its normal idling speed but fails the HC check, re-check the HC level at a high idle speed of 2000rpm. If the HC reading is 1200 ppm or less, the vehicle will meet both the CO and HC requirements.
. the CO requirement must be met with the engine running at its normal (low) idling speed
. do not use a cold start/cold running mechanism to achieve a high idle speed. Instead, apply light pressure to the throttle pedal.
. HC not applicable to Compressed Natural Gas (CNG) fuelled vehicles.

if its only failed on hc at idle did the tester re test hc at 2000rpm

Post by **toomanytoys** » 14 May 2008, 22:43

clean air filter... oil and filter change and take it up the bypass... give it some stick and then take it in... worth making sure the chokes are coming off and not stuck through lack of use..... if you want to be sure of co pass, turn the co/idle screw down 1/4 turn....

Post by **Kilgore** » 15 May 2008, 06:30

Ok thanks.

I'm going back in again this morning so will try all your suggestions and will post the outcome.

Cheers

Post by **Kilgore** » 15 May 2008, 08:33

Ok, just got back.

Yep, they are telling me the poor running and HC emissions failure is due to water ingress into the petrol tank through the filler neck. Apperently water can run down the van sides and in through the area around the petrol cap. The filler neck is perished and a tank that has had water in it will probably cost more in labour to drain with the chance of it rusting from the inside.

I think the tank is a bit tired anyway as when you put more than 2 thirds of a tank in you get a strong petrol.

Waiting for a quote now on petrol tank replacement. They assure me they can fit a replacement '81 tank although I thought the only option these days was a converted 85on tank. Maybe I'm wrong.

Has anyone else had experience of driving a van with water contaminated fuel? It seems to drive as if on 3 cylinders with the occassional misfire.

Thanks for your comments.

Dale

Post by **toomanytoys** » 15 May 2008, 10:27

Before comiting on it.. it could just be the rubber neck at the filler end, and the breather pipes that need doing.. the filler neck itself may be rotted...

Now, I thought you could get a filler rubber to fit the tank that fits the plastic filler neck.. if the tank is ok...

Post by **Kilgore** » 15 May 2008, 10:42

They assure me it's the metal filler neck as well between the rubber and the tank.

I'm getting quotes on full replacement or replace filler neck and drain tank (which could push up the labour). I will post when I get the call.

thanks

Post by **ben50** » 15 May 2008, 14:08

Hi,

Just Kampers do a replacement Fuel filler neck for CU Type 25s Don't know if they are any good but there are £45.00 Part number J10757.

Just read about the fuel filler from JK in VW Camper and Bus for £14.99 but on the Just Kampers Site if actually appears to be an oil filler neck

Cheers

Ben

Post by **Kilgore** » 15 May 2008, 15:50

Cheers Ben

Thanks for that. Yes that would be an option. The filler neck certainly needs replacing which will need the tank dropping out I would think. I will then get them to inpect the tank.

Might be more cost effective to replace that as well rather then 3 hours labour cleaning a 27 year old tank that might rust through in a year or two.

I will post any developments.