Make sure you check all the hoses around the n249 at the front of the engine as these can be known to split.

Yes but why would the split not be there if I restart my engine :confused:

Does the fault code come up every time you have no boost then or just randomly?

Does the fault code come up every time you have no boost then or just randomly?

Every morning (More so now that the car is cold)

If I drive 5 mins down the road(I can tell there is no boost)

Pull up turn off and restart drive away with full boost

So it can't be leak related :confused:

Could it be something expanding when its warm and stopping the boost leak.eg slighly loose flexi pipe on to aluminium pipe.When its cold it leaks when its warm expands slightly and seals it.

Could it be something expanding when its warm and stopping the boost leak.eg slighly loose flexi pipe on to aluminium pipe.When its cold it leaks when its warm expands slightly and seals it.

I hope it's the pressure hose

As I said to you I will know on Friday

Well I have just been out and fitted the breather hose in this thread http://www.briskoda.net/forums/octavia-i/could-problem-17705-a/98409/

my vag-com is at work but I started the car and it's got full boost

So I need to clear the code and see if it comes back?

I have no idea what the pipe is supposed to look like on the inside but it was full of crusty oil on all 3 ends!

I will report back tomorrow after I have cleared the codes

My boost loss problem is definitely not temperature related as it happens randomly all the time and in all weather conditions. The car will be fine, I park up for an hour and when I restart the engine:mad: "What no boost." Or at least no higher boost. On a few occassions I have lost boost while driving. This always seems to happen in the same place on a local hill. Powering up in 4th and slowing/changing down to 3rd to take the bend, then the boost has gone. Does this give any more clues to anyone?

Well I still have NO error codes

Well I still have NO error codes

Excellent

Amazing how nice the car feels when you've fixed something so simple.

Excellent

Amazing how nice the car feels when you've fixed something so simple.

Yes it was nice to have full boost first thing this morning

Nice one Fezboy. Hope it has solved the problem. I took a look at my breather pipe yesterday and it's as soft as a boiled turnip. There are no obvious splits but I can see how it might easily collapse. For the sake of £20 or so it's worth trying. I'm not sure what other hoses to look at (not knowing enough about car mechanics) but some of the substantial looking ones around the dump valve seem a bit squidgy as well.

How does one get hold of VAGCOM anyway?

Nice one Fezboy. Hope it has solved the problem. I took a look at my breather pipe yesterday and it's as soft as a boiled turnip. There are no obvious splits but I can see how it might easily collapse. For the sake of £20 or so it's worth trying. I'm not sure what other hoses to look at (not knowing enough about car mechanics) but some of the substantial looking ones around the dump valve seem a bit squidgy as well.

How does one get hold of VAGCOM anyway?

Oh well it lasted 2 days :(

I have the pressure hose to do next

As for vag-com have a look on the Ross tec web site(Uk suppliers)

Awe no !

The hose that you first replaced, was done on mine too, but only as it was definately spit, and wasn't getting 17705 fault at the time.

After replacing the pressure pipe, the fault went away, but i can guarantee i still go into limp mode every few days.

But vag-com shows nothing new, always when the car is cold too.

But after reading how many others seem to do it, i'm not worried about it.

Sorry to hear that. It sounded like you had sorted it as well. Thanks for the info.

I'm worried about it only from the point of view of selling on the car. It does spoil the enjoyment somewhat, especially after all those ££££.

Well all the standard hoses & a new pressure hose have now been fitted and the problem is still there :thumbdwn:

No turbo boost - help please - SEAT Cupra.net

Interesting on page 3 about having the problem mapped out :rubchin:

So whats the latest then ?

Are you still getting the Engine Management Light on ? (giving the 17705)

Or is it now the car is just going into limp mode ? Giving reduced boost.

So whats the latest then ?

Are you still getting the Engine Management Light on ? (giving the 17705)

Or is it now the car is just going into limp mode ? Giving reduced boost.

Yes same problem every day since the mapping

Never had any lights on the dash

Just don't have any boost in the morning which makes me think it's an issue with the map!

Well i'd take it as the 17705 being solved then.

As when i had mine, it made the light come on.

I still get the same problem as you though when it's cold.

Although !!

If i take the car over 5psi from cold at anypoint, it never goes into limp mode, but if i drive slow, and under 5psi for a few miles, it wont boost over 5psi unless i stop/switchoff etc.

I'm sure i started a post about that ages ago.

It doesnt bother me though.

Just don't have any boost in the morning which makes me think it's an issue with the map!

Have you been onto Jabba about it, and do they know of any other cars with the same fault????

Perhaps posting a thread on Seat, Vag20v, UKMK4's and other related forums, asking if any other Jabba mapped cars have the same fault, and if so, how did they cure it?????

Does seem strange that it only happened after the map ?????

Perhaps you could change your sign in to :-"17705"...Sorry Andy, could not resist it..............LOL

Hopefully we can start a thread to find out if anyone else has had a similar problem with a Jabba map.

But at the same time, we dont want it to turn into a slagging match, so i think we'll check with Jabba first to see if they mind.

Well I will be the phone to them again tomorrow

Please note this is NOT a hesitation problem or a boost leak or split hose!

I need to drive my car morning or evening and then restart it to have full boost :thumbdwn:

This problem was not on the car when it was running Revo or Revo stage 2 and there were no fault codes present!

Hopefully we can start a thread to find out if anyone else has had a similar problem with a Jabba map.

But at the same time, we dont want it to turn into a slagging match, so i think we'll check with Jabba first to see if they mind.

Johnny,

I think from the tone of the post you can tell that I have "NO" intention to start a slagging match, as I have no axe to grind with Jabba.

Its just that Andy has a problem with the car, and "IF" Jabba cannot fix it, then to go to open forums might reveal others that have had, or still have the same problem, and that way try and find a cure for the problem.

Johnny,

I think from the tone of the post you can tell that I have "NO" intention to start a slagging match, as I have no axe to grind with Jabba.

Its just that Andy has a problem with the car, and "IF" Jabba cannot fix it, then to go to open forums might reveal others that have had, or still have the same problem, and that way try and find a cure for the problem.

Oops..Sorry Gerry. I didn't mean that to sound like it was at you.

I was more meaning in General, as you know how some threads can spiral out of control.

Apologies about that.

Fezboy,

I have an idea. Could it be the N249 at fault, or one of it's vacuum feeds at fault??

As far as I know the N249 has the ability to switch between different vacuum supplies to actuate the DV. If you have the 17705 fault and your boost is down, maybe the N249 is supplying the DV with a too higher vacuum feed and hence reducing boost pressure, and bringing up the 17705 code (pressure leak between turbo and inlet "check DV").

If the ECU decides to back off the boost pressure (limp mode?), I believe it tells the N249 to switch to a higher vacuum pressure. Maybe, just maybe, the N249 has broken/degraded and it is selecting the wrong vacuum feed. But when the car is restarted, the valve resets, and then selects the correct feed.

Does anyone know where the N249 sources it's vacuum feeds from? Intake manifold, brake servo???

Comments please......

Found some very interesting reading aswell:

Removing N249 valve - How To Guide - SEAT Cupra.net

So the N249 would be getting it's vacuum from the reservoir in a reduced boost state.

Maybe the wiring on the N249 is damaged. Or maybe it's nakkered. But it's definately selecting the wrong vacuum feed.