Unusual Whistle, help please!!

S3 finatic

S3 finatic

Limp mode
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I recently purchased an A3 2.0L TDI 140 Sport. On purchase the car i could honestly say sounded and drove perfectly.

As weeks have gone by an unusual whistling noise can be heard, but it goes when you rev the car. If you leave it ticking over it is that loud its irritating. Also when you rev the car you can faintly hear what sounds like a dump valve dumping.

From outside the car i have pin pointed the noise to the top of the fuel tank. So I have removed the rear seat and panel to view the top of the tank, but it is louder from the outside of the car.

Only thing left to do is remove the fuel tank, which i am leaving as a last resort.

Any ideas?

I have not got vag, so looking for advice before i pay someone to plug her in.
 
Thought it was the seals on the intercooler, had a look today they were shagged. Changed them with oem parts which sorted the leak out, but now the noise is clearer/louder. And you can very clearly hear a dump valve chatter when taking your foot off the accelerator.

I did pin point the dull whistle to the exhaust pipe though!! The noise can be faintly heard at the turbo end, but louder from the back. I am assuming its louder at the back, because of the trombone effect.

Could it mean my Turbo is ackerd? Or the Cat?

Is there any way of checking it without throwing money at it?

Is there a diverter valve fitted to a diesel? Or a valve of some kind that would make this noise?

I'm pretty sure the chattering and dull whistle are related....
 
All turbos will chatter there is a dv . All turbos whistle a bit aswell. Mine does. I dont have a radio in the car at the moment so I lock on to the noises more. Quite annoying but oh well
 
I know Turbo's whistle, but they should whistle when you rev them. Mine is the opposite, mine has a dull whistle when on low revs the soon as you put your foot done it stops.

Great! It has a DV valve, this will be easier to test and eliminate..

Now to install this DVD manual and locate it..

Cheers
 
its just the turbo! The dump valve sound is a dump valve on the PD140. Re the whistle sound "if" it sounds like a police car is following you then its the turbo bearings, they are just noisy on some turbo's. If its getting louder or you can hear what sounds like a supercharger whine (you will need window down) then its about to give in.
 
Cannot find a DV or a PD140 on my workshop manual!
Would these be known/called something else?
 
When the exhaust goes on my Caddy van I get the whistle and a swoosh when I short shift like a dump valve. check the back box for leaks.
 
It does not sound like a police siren following me, with the window up or down. And it only does it on very low revs or tick over.
Today the car went into limp mode when i floored it in 5th, so theres an issue somewhere!!!!!!

Baffled!
 
audi upgrades
Still Baffled!!

Looks like i'm going to have to live with it until i can afford to get it into a garage.....
 
Is there any more smoke than usual on tick over,when you floor it etc? it could be a blocked dpf or a number of things especially if its going into limp mode but this normally boost issue are a main provider of this with things like boost pressure regulator,sticking vains but they wouldnt normally be loud as your describe and more vice-versa as in worse when your driving
 
No un-usual smoke, and not using to much oil. I always assumed the first give away for a turbo giving up is burning oil, lots of smoke, and whyning.

The noise is like a fan belt slipping, but quieter. It is worse on tick over, but the soon as you touch the accelerator it stops! It is also audible when slowing down through the gears (taking your foot off the accelerator). It does not do it straight away on tick over, it's as if it is building up pressure.
I think it's a boost leak, as i had similar noises with my 1.8T, and S3, these were both solved by replacing the DV and some hoses. But i cannot find any faulty hoses, and they do not have DV's.

Lets try something else!
What makes the whoosh noise when i change gear if it is not a DV? Could this be leaking and causing the noise.?
 
Looked at a car the same as mine yesterday, and the whooshing was exactly the same as mine, it had the same power as mine, but not the whistle that is irritating me....

I'm hoping some of the users can help me rule out some faulty parts..

Could the Exhaust Gas Recirculation Valve cause my fault?
What would happen if this was faulty?

Could the Charge Pressure Controller cause my fault?
What would happen if this was faulty?
 
mike foster said:
You can discount the dpf as the 140 engine does not have one. The 170bhp engine has one.
Click to expand...

Sorry if incorrect this maybe me getting confused but i thought it did have a dpf as such ? i didnt think they had the old particle filter set up like the old mk4 golfs etc?
 
I had just the same noise symptom; the sound is hard to locate, seeming to come from all around. It turned out to be the fuel pumps. Mine is a quattro therefore has a split tank and the noise only completely went when both fuel pumps were replaced. The second one being mechanical slave to the first.
 
Last edited:
I think mine has 2 pumps, one inside the fuel tank, and a tandem pump on the side of the engine, which i believe is belt driven.
These should be easy to check. I have unplugged the one in the tank and it made no difference, not sure if this is good or bad! I'm assuming the Tandem pump can be tested just by removing the belt and starting? That sounds a tricky one.....
 
S3 finatic said:
I think mine has 2 pumps, one inside the fuel tank, and a tandem pump on the side of the engine, which i believe is belt driven.
These should be easy to check. I have unplugged the one in the tank and it made no difference, not sure if this is good or bad! I'm assuming the Tandem pump can be tested just by removing the belt and starting? That sounds a tricky one.....
Click to expand...

Have we gone off the idea of dpf now ?
 
Tandem pumps are driven straight off the end of the cam so there is no belt
And they dont whine either.
its your turbo.
If its not going into limp home mode its probably ok for know.
as above - no dump valve on these - they are vnt types - vanes inside the turbo move to control boost.
and definitly no particle filters on tthe pd140 engine.
I have a turbo coming back tuesday from balancing after i fitted new bearings and turbines and will be fitting it the following weekend.
My car sounds like a police siren and has the dump valve sound on accelerator lift off.
Have changed the two bottom boost pipe seals - made no difference.
Will post my results when its done.
Car doesnt use oil and has plenty of power and gets 60mpg if I eco plod it
 
just re read the first post - i also get that high pitched exhaust whine at idle that builds unless you dab the throttle.
was wondering if the cat or a back box baffle inard was loose.
Athough its hard to tell when driving as the bearings are whirring in the rear wheels!
I used to have a B5 A4 - i have to say the A3 quality is some what inferior and thats being polite
 
My car is a Quattro and so has a split tank with a pump in each, the second being a mechanical slave off the first, sending petrol from one tank to the other. They are both submerged in petrol in the tanks.
 
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I see you have had limp mode. You need to get it on diagnostics. Your looking for boost deviation error. This would indicate carboned up vnt mechanism. Can lead to a new turbo.
 
I have heard of something that can be used to de carbon/soot the turbo. Anyone know where i can get this from? And what it is called?
 
The dpf is available as a retro-fit kit if you really want to fit one.

The standard BKD engine does not have one.

If you want one it costs £1,378 as a kit to buy from Audi !!

It seems like the 'Green' brigade might consider it a worthwhile extra but at that price I wouldn't be interested !
 
Sorry if my mistake i thought they were as standard as Statller been doing a run of removing them on 140 + 170's lately so i thought they were standard issue for who would pay for that putting on there car as an extra if meant paying for it ????
 
Mine does not have a particulate filter, so that rules that out.

Surely Cillit bang is going to damage the turbo?
 
Inotech or mr muscle might help with a lightly coked turbo but yours is going in to limp mode. I tried all the clean it on the car nonsense and wasted weeks under the car.
Trust me its a turbo off job.
If you take it apart you will see.
At the very best you will have to split the turbo to unstick and clean the vnt mechanism.
there should be about 11mm of travel in the vnt lever if there isnt its coked up.
The problem is that coked up leads to the turbine disintegrating and the bearings getting sloppy.
Too much play in the bearing results in the compressor blades milling in to the compressor housing.
Its not that hard to get it off if your handy. But you will have to get a new oil feed pipe because you will only get the old one off by cutting the old one and undoing the nut with the turbo on the bench. there isnt enought room to do it on the car.
I removed the drive shaft to give enough room to drop it to the floor.
 
Before taking it off you should get it diagnosed - check out vnt mechanisms on youtube - you can use a hand held vacuum pump to move the vnt lever or get a vcds output test done on the vnt mechanism.
If it takes a big vacuum to pull the vanes or the movent is jerky it shows the vanes are sticking.
a shot of wd40 may cure it when cold but the working exhaust temps soon put a end to that.
I am not trying to be negative - just trying to get you on track with a fix.
 
Just a quick update
Have just fitted a recon turbo to mine
As I reconned it i know its been done properly not just cleaned.
New bearings and turbines then sent away for a balence.
Any how the whine at idle has gone and the police siren when lifting off throttle.
No turbo stalling sound either.
Havent been for a drive yet as i broke all three studs on the ball joint when removing the drive shaft for better access to the turbo.
One thing i would say is when looking for whines at idle you should turn the aircon and interior blower completely off as they make a bit of noise in their own right.
Old turbo inards looked resonable other than a few stuck bolts taking it apart
 
Stripped mine today, the inside of the turbo was completely clogged. Took it to pieces and cleaned it using diesel, and injector cleaner. It was nice and shiny when i put it back together. :eyebrows:
Not tested yet, as i ran out of daylight when i was putting the exhaust back on. Will confirm results tomorrow.

Internally the turbo looked fine, with no bearing play..

For future reference you do not need to remove the drive shaft, i got mine out no problem by removing the complete exhaust system in one piece. And pulling turbo out the gap left. Only took 15 minutes.

I did not need to cut the oil feed pipe, i removed it with a 17mil open ended spanner to problem. This may be due to there being no cat in the way, as i removed the exhaust system.
 
audi upgrades
Well!

Car started first time, and at first no whistling! Took it for a gentle drive, and instantly noticed there was more power.
After i got back, i left it ticking over for 10 minutes and whistle appeared again. It is definately coming from the turbo, so still none the wiser.
 
Anyone know the best place to purchase a turbo core, for my54 plate 2.0L TDI Sport?
 
Radesigns in Blackpool. They are on the web.
My siren sound has gone. There is a slight whistle under load and a slight dump valve sound if I am doing faster gear changes. Relaxed changes don't get the stall sound at all. All the heavy turbo stall/ scuttle sound has gone. And it seems a smoother power delivery. I am happy with mine but have developed a theory that these turbos are inherently weak for the job in hand. The vnt mechanism should be sealed away from the exhaust gas it just shouldn't get soot in it.and this day and age it should have cartridge bearings. so it will probably go again. I cut a cheap ring spanner with a slot to undo the oil pipe. Depending on where the nut lies you may not get a flat in there, you got lucky!good info on the cat thought.
 
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