Hissing sound coming from rear of car when ignition on!?

[JP1993]

Hello,
Recently bought my first SEAT - 63 plate Leon FR 184 TDI on 37k, absolutely brilliant car and really happy with it.

However I don't know if anyone else has this issue when the cars ignition is on, there's a fairly loud hissing sound coming from the rear? Seems to be directed towards the fuel tank area, car drives fine and there are no faults showing in the menu.

Does anyone else have this issue and know what it could be?

Cheers!

 

[Walone]

Hello,
Recently bought my first SEAT - 63 plate Leon FR 184 TDI on 37k, absolutely brilliant car and really happy with it.

However I don't know if anyone else has this issue when the cars ignition is on, there's a fairly loud hissing sound coming from the rear? Seems to be directed towards the fuel tank area, car drives fine and there are no faults showing in the menu.

Does anyone else have this issue and know what it could be?

Cheers!

Probably the fuel pump.

 

[JP1993]

I had a feeling it would be! Do you reckon it'd be a warranty job?

 

[Walone]

I think it's just a normal 'thing'.

 

[psychobob]

My 184 does this aswell. It is "normal". It follows what you describe and also after a good run

 

[JP1993]

Ohhh that's alright then, I had a feeling it was something nastier lurking. Cheers for putting my mind at rest!

 

[Aardvark]

Yep we have two 184's a 14 plate ST and 16 plate SC and they both make this sound.

Remember that fuel pressure in a diesel is much higher than a petrol car and by the time tit gets to the fuel rail it is at least 1000 bar and can be much more.

 

[JP1993]

I'm with you now, it's my first diesel so noises like this are quite alien to me! Random but do you find either of yours take a couple seconds to start? Seems to be more so when it's been warm the past couple of days, would it just be another characteristic of the engine?

 

[Aardvark]

I'm with you now, it's my first diesel so noises like this are quite alien to me! Random but do you find either of yours take a couple seconds to start? Seems to be more so when it's been warm the past couple of days, would it just be another characteristic of the engine?

Yes they always do and to add an extra bit of insight I also have a diesel car for work, a 320ED BMW so I can compare across 3 different diesel car's and my wife's petrol Corsa.

If anything the BMW is the slowest to start and takes longer for the pre-heat to work before the engine cranks over.

Starting from hot is usually a matter of turning the key, wait until you hear the fuel rails pressurize up (hissing sound) and then cranking the key.

If you use the stop/start function in traffic you will find almost instant starting when you depress the clutch to engage a gear because during this interim stop engine phase all the fuel system remains at full pressure. I think when you manually stop the car, after a few seconds you will hear the system go through a series of shut downs. I had a Citroen DS4 diesel that used to make humpback whale noises for about 5 minutes after turning off the engine and my youngest son has a 1.4 Ibiza TDI ST FR that makes a soft hooting like a baby owl.

 

[JP1993]

Cheers for that pal, makes me feel a lot better knowing that they're normal "issues" as opposed to anything else. Feel like I can properly enjoy the car now instead of having that worry at the back of my mind!