Ive been thinking. Dangerous, i know.

People recommend (as have i done in the past) not to vent a Fabia tank unless doing quite a few miles straight away, as youre using the expansion tank.

But, is it that bad on a petrol?

So. You fill up, vented and park up. Fuel expands, and if it needs to, it goes out of the breather pipe (which it has to have, or it would vacuum as the fuel level decreases?) so the odd drop of petrol goes underneath the car, then when rhe sun gets on it, it evaporates.

Wheres the danger in that?

Okay maybe abit worse in a Diesel, as its bloody slippy, but itll only be the odd drop?

And if it was that dangerous, why do Skoda give the end user (lets assume end users have no clue about expansion and contraction) the option of doing it? Afterall, everything should fail-safe where possible. 

Could somebody please fill me in on what im missing?

Cheers (:

Edited 8 January, 201610 yr by fabiamk2SE

Yes it's bad. On a petrol you have a charcoal canister that filters out the fuel vapour from the tank before recycling it into the engine via the purge valve (N80 iirc).

If you vent the tank and carry on filling the fuel will eventually travel along the vent line and fill the charcoal canister damaging it. Fuel as a liquid and also damage the purge valve and you will register a rich mixture fault.

Yes it's bad. On a petrol you have a charcoal canister that filters out the fuel vapour from the tank before recycling it into the engine via the purge valve (N80 iirc).

If you vent the tank and carry on filling the fuel will eventually travel along the vent line and fill the charcoal canister damaging it. Fuel as a liquid and also damage the purge valve and you will register a rich mixture fault.

ah okay. its making more sense now Ross, cheers. 

 

So, why would Skoda give the end user that option? no other cars do it that im aware of? our Yeti doesnt, T5 doesnt, Polo didnt etc etc.. and its all too easy to press the vent switch with the filler nozzle? 

 

Genuinely curious

 

cheers! 

 

Edit. so thats in the filling process? so its never good to do, full stop? before  a long trip or not? 

Edited 8 January, 201610 yr by fabiamk2SE

It's a good question tbh. I only know we had a bulletin listing the fault codes and symptoms that occur when someone has done it and that warranty may be refused if it's not a component fault and parts have been damaged by misuse.

I'm pretty sure they have been deleted on petrol engined cars now. Although it was quite useful to depressurise the breather system before working on it.

It's a good question tbh. I only know we had a bulletin listing the fault codes and symptoms that occur when someone has done it and that warranty may be refused if it's not a component fault and parts have been damaged by misuse.

I'm pretty sure they have been deleted on petrol engined cars now. Although it was quite useful to depressurise the breather system before working on it.

hmm. it just seems very odd to me tbh mate. Yanno my job, im a Gas Safe heating engineer, so i deal with expansion and contraction on a daily basis. To me it seems odd.. i cant really square it up in my head. Boilers fail safe where possible, every end user is assumed to be a complete idiot, so it wont do anything thats slightly dangerous or if it theres something to make it safe.  So i cant to be perfectly honest, understand why a vehicle would give the end user the option to potentially damage itself. 

 

So, if the user unintentionally uses something which is there to be used, causes damage, takes the car back to the dealers under warranty (most likely completely oblivious of what they've done. 'i just put fuel in it?') they get told their warranty is invalid and they'll be paying the cost's? 

 

seems abit crazy? 

I'm pretty sure it instructs you not to press the valve.

But yeah I agree.

I'm pretty sure it instructs you not to press the valve.

But yeah I agree.

A combi boilers instructions instruct its users not to increase pressure as high as 3bar, but if they do it fails safe and blows off to outside. 

 

i cant see how a manufacturer could blame their user for using an option which was given by them. It's really quite easy to do it accidentally, its the reason i only put £20 or £30 in at a time. I cant believe that somebody hasn't done it, caused damage, then ****ed Skoda uphill and down dale. I'd defo argue its a design fault, wouldnt you? 

 

Cheers for your info Ross. I don't mean to sound as if im quizzing but i cant get my head around it, im appreciative you've given your input and it means alot given i know your position in the past. 

 

Thanks again  

Thinking logically.

Would Skoda have a leg to stand on in court of any damage caused by a design of their own?

If they do state in the owners manual not to use it for the purpose of overfilling then yes I guess. However as you say it's quite possible to activate it accidentally.

Not sure if they are fitted now anyhow. Or what it's actual function is tbh.

The thing to do is. look at your Fuel Cap, and look at the Slide you vent with.

 

When you fill up just normally, brim or what ever, and replace the Cap and turn then lock in place, the slide is pushed, it has vented.

Edited 8 January, 201610 yr by GoneOffskiroottoot

it does not mention in my Owners Manual what exactly i should be doing tbh. So assuming im a complete retard (i dont think its fair to assume the general motorist is?) so i could do anything? i could insert the fuel nozzle, vent without realising and then damage the charcoal canister whilst dreaming into the sky (people do that too, dont they?) and not even realising? all ive done is fill my car with fuel until the nozzle clicked? Nobody's ever mentioned to me about venting a fuel system? This is the first ive heard of it?

It's not even mentioned in the manual, so within or out of the manufacturers warranty, im not using the vehicle with in-accordance to the Skoda's Owner's Manual for this vehicle.

i see no problem, based on the publication i was supplied with the vehicle?

I'm just playing the **** here, as we're all allowed to do.. yeah? haha

so ill vent my tank and if theres problems.. ill see Skoda in Court.. technically?

Edited 9 January, 201610 yr by fabiamk2SE

The thing to do is. look at your Fuel Cap, and look at the Slide you vent with.

 

When you fill up just normally, brim or what ever, and replace the Cap and turn then lock in place, the slide is pushed, it has vented.

 

sorry to have to make you elaborate George. So you're saying that the fuel cap makes the fuel system vent anyway? 

 

Tbh, it all seems a shambles to me. Theres no proper publication supplied with the vehicle, theres no guide to what anything does, it just guides me to fuel type etc etc. 

 

So i could vent that... keep filling (accidentally keeping venting, as i dont know what venting is) and as technically cause a problem. However, i know nothing. Skoda hit me with a bill and we all get to wear our best suits to court. 

If they do state in the owners manual not to use it for the purpose of overfilling then yes I guess. However as you say it's quite possible to activate it accidentally.

Not sure if they are fitted now anyhow. Or what it's actual function is tbh.

i've looked in the Owners Manual of my 2013 Fabia, nothing is mentioned. 

 

Is it mentioned in your 2011 Scout manual?  

i have a manual?

The thing in the filler tube is not intended to be user operated, ever. The fuel cap, when screwed on, is what is meant to press on that, and 'unpress' it when taken off.

That's why there's nothing in the user manual.

 

Easily done accidentally though, and so a design that is a little questionable.

 

I found something about the system in an SSP a while back, it's all a cunning way of keeping fuel vapour (a strong generator of smog) inside the tank/charcoal canister system while and after refuelling. I'll see if I can re-find it later.

It's to do with Benzine vapours iirc. It's coming back to me, at least in part. Fuel nozzles in the States have extractors on them to suck the fumes up as the tank fills up.

Ah okay. Its getting clearer haha.

Still easily done whether its intentional or not. Dont see how Skoda could blame the user for something which happened when ther were just filling up.

Maybe just as well that its gone tbf. Seems a pointless danger

Comes back to that when you are filling up and setting off somewhere and you brim the tank and get 40 litres in, 

you can vent it and get 7 more litres in and set off and have a bit more range if you want.

Have your Cans in the Boot as well. (Supposedly only 10 Litres.) and you are good to go.

If you are wanting 99 ron without having to track it down like in parts of England then its a good thing IMO.

 

If you do not like it, dont want to do it, do not need to do it then 'Just say no!'.

Edited 9 January, 201610 yr by GoneOffskiroottoot

so ill vent my tank and if theres problems.. ill see Skoda in Court.. technically?

Put it this way, you go out in your car, you think oh, it doesn't tell me not to crash my car into a motorway bridge support, I'll do this (because lets face it, we are to assume the end user is a moron) And the car should have a fail safe feature that stops it hitting a big lump of concrete so it's not your fault. Do you then go to court and try to sue Skoda because the car had a feature that allowed you to crash into a bridge?

Put it this way, you go out in your car, you think oh, it doesn't tell me not to crash my car into a motorway bridge support, I'll do this (because lets face it, we are to assume the end user is a moron) And the car should have a fail safe feature that stops it hitting a big lump of concrete so it's not your fault. Do you then go to court and try to sue Skoda because the car had a feature that allowed you to crash into a bridge?

Dont be silly. Its absolutly nothing like crashing the car in to a bridge. Thats just stupid.

If you fill your car (vent without knowing) then damage it. How can you be at fault? Nobodys told you to be careful of the lever in the filler neck, you havent even noticed it. How could it be your fault? Youve only filled your car with fuel?

Comes back to that when you are filling up and setting off somewhere and you brim the tank and get 40 litres in,

you can vent it and get 7 more litres in and set off and have a bit more range if you want.

Have your Cans in the Boot as well. (Supposedly only 10 Litres.) and you are good to go.

If you are wanting 99 ron without having to track it down like in parts of England then its a good thing IMO.

If you do not like it, dont want to do it, do not need to do it then 'Just say no!'.

I am lucky that ive got 99Ron about 5 miles away, over arguably the nicest road in the Peak District. Never used it in the Fab though haha.

I know how venting is recommended on here, but not everybody uses a forum. A Fabia is a car that people with hardly any interest in cars could buy. They could vent without even knowing. They just put the nozzle in the tank at an angle without thinking. Why would they think about it? Skodas never given any users any literature on it?

Nail on head again.

 

I could link the posts that are made on this forum from time to time where someone is curious to why all of a sudden their vehicles takes 

more fuel in.  They vented by mistake or another driver did, and the routine is disrupted.

But even i am bored now so i will not bother.

 

I reckon in 4 years i Vent a Fabia vRS tank a minimum of 2 times a month, so that will be 100 plus times.

I know i will live to regret it, or maybe not.

 

'The grave digger.'

Nail on head again.

I could link the posts that are made on this forum from time to time where someone is curious to why all of a sudden their vehicles takes

more fuel in. They vented by mistake or another driver did, and the routine is disrupted.

But even i am bored now so i will not bother.

I reckon in 4 years i Vent a Fabia vRS tank a minimum of 2 times a month, so that will be 100 plus times.

I know i will live to regret it, or maybe not.

'The grave digger.'

I know mate yeah. Theres no end of people who have done it accidently. Im guilty too. The little weld on the filler nozzle has been caught on it before.

I guess nobody really knows how theyd stand legally if that canister did fill with fuel. I certainly wouldnt be paying the bill, to be perfectly honest. I do think acting thick (im good at that sometimes ) would be all is required haha.

Do not forget the original purpose of tank venting!

 

If the tank was not vented, the flow of fuel would be stopped, and/or the tank would collapse from the vacuum generated. In my early days in the trade, people used to buy 'a new petrol cap' - without checking if there was a small relief hole built in. I got called out to several collapsed tank jobs because of the lack of simple relief. Perhaps things have progressed on from my days (?) - if so, ignore this post.

Principal is still the same except you can't vent to atmosphere.