Air Rushing Noise??????

[Norfolk Jim]

Since having a new turbo fitted on my 2007 9-5 Vector Sport est 1.9TiD I have had a strange noise occurring whilst engine under load accelerating.

The car is running absolutely fine and after 500 miles the turbo is spinning fine but having allowed it 500 miles to settle in I have noticed when using a bit more right foot there appears to be a rushing of air noise coming from the engine - all I can describe is it sound like the rush of air through an intercooler - I remember this from my old 9k Aero when Abbotts put their big intercooler on that - hit the loud pedal and you got the sort of deep throated rush of air noise; this sounds like that  It runs fine, mpg is good and everything seems sound. The garage checked out all the pipework and nothing appeared loose etc so just wonder if now the turbo is working properly it might be me hearing intercooler??

Is this a sign of new intercooler being needed? Garage seem to think mine is ok but............................

Any ideas gents - now you've all got over the Christmas binge time............... la la la

[sgould]

Don't really know, but holes in the intercooler and it's pipes are supposed to give you lots of black smoke out the back....

[Audax]

Don't really know, but holes in the intercooler and it's pipes are supposed to give you lots of black smoke out the back....

Not necessarily, a big split will but a small hole won't. What I'd be suspecting would be that as the turbo was just replaced a hose clip or gasket isn't tight somewhere or that the old turbo was noisy/rattling and covered up the sound. It's pretty easy to pressure test an intercooler so it's probably OK if they've check it out.

[Norfolk Jim]

No piles of smoke out the back only a small amount when accelerating noticed last night in the dark with 4 people on board.

It's definitely rushing air sound and quite loud in and out of the car!

Puzzling

[Audax]

When they checked it, did they just do a visual inspection or pressure up the intake system when testing? It really does sound like a hose clip not on quite right!

[Norfolk Jim]

I did wonder about a hose clip as this afternoon I really booted it on way to Cromer and having kicked down and got into high rev range I was taken back down to earth with emissions light coming on............I suppose this could be triggered by an escape of air? I haven't read codes present but it did a regen only a couple of days ago - you know that smell of kerosene when it does it.

[Audax]

I did wonder about a hose clip as this afternoon I really booted it on way to Cromer and having kicked down and got into high rev range I was taken back down to earth with emissions light coming on............

That is a really key signal that something has not been put back right (I know this from experience as everybody makes mistakes now and then!), I'd call them and ask them how they checked it, doing these checks visually would make it easier to just miss something.

Hopefully it's not another fault occurring after the other but I did know of one car that after having a new turbo needed a new inter-cooler hose a week later. We put it down to thinking that the car wasn't reaching target boost before the turbo was replaced and after the new one it was producing more boost and therefore pressurizing the system as it should, unfortunately the old hose was only holding on before and went pop in exasperation. 

[mikeloadsasaabs]

We had an error code come on some 6 years ago - late in the evening, wet, 5 people in the car, 100 mile journey ahead... car seemed to be running OK, so drove with it for a couple of weeks. Can't remember what the code was, but Ian at Saabtech checked it out and it was a loose clip on the intake hose, where it meets the turbo I think. Ian explained it was often a cause of this problem, as it's difficult to see and therefore easy not to reconnect properly. It had obviously been like it for a while, but the error code suddenly to pop up.

Hope it's nothing too serious anyway Jim.

[Norfolk Jim]

Thanks Mike and Audax.

I am going to see them in next couple of days as I wonder if a hose hasn't been completely secured. The one I suspect is the large intercooler hose which was replaced in autumn at main dealers to the tune of £175 for the part - so that's brand new. My other suspect is the one coming from air box which connects to left side looking from front.

[Norfolk Jim]

Ok I have now read the codes and the usual P1901 came up but the new one is P0234 - Engine Overboost Condition. That latter one occurred when putting foot down hard.

As I have a new turbo complete does this mean it sounds like an air leak on one of the pipes??

Whilst turbo was being replaced he did also replace the oil trap for me at the back of the engine. He also took out the EGR valve and said it wasn't too bad and gave it a clean and replaced.

Ideas chaps??

[Audax]

Ok I have now read the codes and the usual P1901 came up but the new one is P0234 - Engine Overboost Condition. That latter one occurred when putting foot down hard.

Are you 100% on it being P0234 and that you didn't mix the numbers up? This is because it's not listed as a code in WIS for the 9-5 *however* I've had this before and just used the 9-3 diagnostics instead as Saab seemed to have forgotten to put all the codes into the manual.

Either way both codes on WIS suggests checking all the hoses and pipes for air leaks on the intake system, air filter, and air flow sensor. All I'd say was that this still points a split or loose hose somewhere on the turbo system or intercooler damage, especially with the description you gave. If I continue the diagnostics by saying the intake system is all good it points to a possibly faulty charge air valve or the VNT vanes on the turbo sticking but that wouldn't make sense given your report of the rushing air sound.