EVAP Purge valves keep failing

[The Toecutter]

I'm on the 4th or 5th EVAP purge valve in the last 12 months. They've all been brand new, genuine Bosch ones. Highly unlikely that they would all be faulty so thinking there must be something else a foot.

Car is a 1.4 (BXW engine). The symptoms manifest as the car not starting when the weather is hot and the car has been sitting in the sun. I have to put the accelerator pedal to the floor and crank the engine for a bit to get it to start, and it stinks of unburnt fuel when it does start.

A new valve is shut, you cannot blow through it. A failed valve is open, you can blow through it, so it's letting fuel vapour into the engine when it shouldn't be. After replacing the valve the car will start fine in the hot weather, until it fails again like it has today! There's no codes thrown and when checking live data the ecu thinks the evap valve is closed.

Any ideas what would be causing them to fail?
I'm thinking I might just block the outlet on the inlet manifold and extend the hose from the evap valve down out the way so it can just vent to the air instead.

 

[dm222]

do you ovefill the gas tank?
ive heard it causes this
which part number are you using?

 

[The Toecutter]

do you ovefill the gas tank?
ive heard it causes this
which part number are you using?

Don't think so, always stop at the first click of the nozzle. I''ve heard that too, and with other cars, so never usually go more than the first click.

They've all been Bosch 0280142345 and that was the same as the very first one to come off the car.

 

[dm222]

Don't think so, always stop at the first click of the nozzle. I''ve heard that too, and with other cars, so never usually go more than the first click.

They've all been Bosch 0280142345 and that was the same as the very first one to come off the car.

Thats the same I used, didnt have problems anymore since 2016

Are you installing in the correct direction? i dont know if it is possible to install in the wrong direction because the wire is short if you do. Is the tube secured in the clamps so it doesnt vibrate as much?

 

[The Toecutter]

Yep, all installed correctly. Can't really get it the wrong way round, there is an arrow showing direction on it too, and everything is secured.

First one was changed in 2017, that must have been the orginal oem one. The second one was changed in spring 2020, since then they have been failing every 2 to 3 months.

Think I might try adding a clear fuel filter before the valve to see if anything dubious appears in there, incase there's some debris getting into the valve. Failing that I'll go for the bypass/delete and see what happens.

 

[vw.man]

I had exactly the same problem with my 1.4 (2009) back in 2019. I searched for info on the problem and it seemed the official fix was in 2 parts: (1) change the purge valve for an updated version and (2) get a software update done at the main dealer. This is all from memory! I thought I'd try (1) first and the problem has never returned.

I bought a Bosch item corresponding to Seat part number 6Q0916517. I realise this isn't much help to you - I can't find anything online now that references a superseded part. Maybe phone the main dealer and see what part number they quote? All I can think of is that if the part(s) you put on bear the same number as the original, then they're all going to be the older part.

Final option: talk to the main dealer about getting the software update.

 

[dm222]

I think there is no fuel going though the valve, only vapour

Probably for some reason its creating too much pressure and damaging the valve

Purge valve, how it works, symptoms, problems, testing

What is Purge Valve or Purge Solenoid in a car, problems, symptoms, purge valve testing, replacement

www.samarins.com

 

[dm222]

 

[The Toecutter]

I think there is no fuel going though the valve, only vapour

Yeah, there definitely shouldn't be any fuel coming through the valve. But if there is that will damage the valve, and if there's something else like bits of charcoal from the canister it could be jamming the valve. If I put a clear filter before the valve I will be able to see 1) if there's any debris and 2) if there is fuel ending up there.

 

[The Toecutter]

I bought a Bosch item corresponding to Seat part number 6Q0916517. I realise this isn't much help to you - I can't find anything online now that references a superseded part. Maybe phone the main dealer and see what part number they quote? All I can think of is that if the part(s) you put on bear the same number as the original, then they're all going to be the older part.

Final option: talk to the main dealer about getting the software update.

I think the Bosch one is the updated one. I've bought one from a SEAT dealer and it was the same Bosch part.

There is a Technical Bulletin on Erwin about the problem, but it says only Valeo valves were effected, it doesn't mention a software update only to change the valve.

 

[dm222]

the vale iself has a filter, maybe open one of the old ones you removed if it is clogged

 

[dm222]

So I solved this problem in my car like 5 years ago and never had the problem again, not even a single time, untill today it was 44 degrees here and the problem returned.

But this time it was worse, it wouldnt start no matter how many times I tried.

After many tries I disconnected the hose to the N80 valve and connected again and finally started but felt a lot of gasoline smell after start.

Honestly Ive tried but cant understand what this system is for during the start of the car.

All I know is that probably will need a new valve soon...