2.0 TDI sounds like it has a boost leak?

G

Goner

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Morning Chaps,

Help if i may, over the past few days my car sounds like it's got a boost leak, if i floor the car from say 1500rpm to around 2800rpm all you can here from inside the cabin is whooshing noises, almost like its windy outside and you can hear it blowing. I don't hear turbo whistle just the loud sound of blown air.

Drop the windows and do the same, sounds just the same but a lot louder, i don't think for one second the turbo is faulty as there are no dodgy noise from that, prior to this excess air noise on boost developing the turbo whistled away as you would expect.

Car is an A3 Sport-back S line, 2.0L TDI 140, 40K miles, 56 plate, manual.

Any ideas which pipes to check first?

Thanks
 
oh also while i think on, between revs 2000 and 2100 at cruising speed the car sometimes jerks a tad (as if it's holding back) only for a split second, could this be related or do i just need to run some diesel and injector treatment through and change the fuel filter?
 
Check bottom cooler hoses mates as blow back oil gathers around the joints with it been lowest point,thus making the pipes not been able to seat correctly allowing movement on spool up
 
You will need to get under the car to check anything in the way of boost hoses as from the top the only one you can check is the connection to the IMF. So you will need it up on a ramp / two poster, axle stands or my favourite way at home a pair of ramps (I've modified a set to extend the ramp so that it isn't so steep with a scaffold plank cut in half and bolted to it)

The connectors are a bit of a pig until you get the hang of them, depending on mileage it may be worth getting a new set of o-ring seals from TPS. I use a combination of screwdrivers to level the spring clips up to release the joint and expandable grips to clip it home again afterwards. The one at the Turbo is a pig, best to undo the torq bolts that hold the metal boost pipe to the bottom of the block to give you room to manoeuvre the hose out.

Oh and a serious boost leak can cause it to hunt, mine hunted like a pig when the connection below the IMF was off.

Good luck.

Paul
 
My pipes under the car have oil around them, it also has a split second hunting, and it sounds like it has a dump valve, its a 54 plate tdi 140, are the pipes servicable with new seals etc? Will i be loosing performance?
 
Sounds the same as mine, I replaced the seals around all the intcooler pipes, although forge intercooler pipes would be a better upgrade, also, about the jerking, I replaced the fuel temp sensor at the front of engine, hope this helps
Cost me about £25 to sort those out
 
My pipes under the car have oil around them, it also has a split second hunting, and it sounds like it has a dump valve, its a 54 plate tdi 140, are the pipes servicable with new seals etc? Will i be loosing performance?

Are you sure that's not my car your driving, I have the same issues exactly, although the dump valve sound has it's days :lmfao:

What will this cost me at a local mechanics? I thought the turbo was on it's way out... Hopefully not though!!
 
I had my car on the forklift and changed my egr valve and checked my boost hoses lots of oil in them.
Think the turbo is letting go had the dreded over boost as well mines 2004 as well
 
All sorted, was one of the boost pipes with a big split in it!

Thanks for your help chaps.
 
Good news - out of interest which one was it ?

The big fat one from the turbo mate, the car is still holding back for a split second around 2000 and 2100 revs.. doing my nut it!

Run injector cleaner through it, running some v power diesel through it, going to change the fuel filter also.. am i still ******* in the wind with regards to the slight stutter?
 
How many miles on the clock and is it the original Turbo ?

Could be the vanes sticking on the Turbo.

Fuel filter is a good call too, I change mine every couple of years (about 8.5K per year).

Paul
 
41K on the clock and i believe it's the original turbo, I'm the second owner.

What's this innotec turbo cleaner stuff (heard this mentioned before), is that a good place to start next do you think?

'Jboo' scanned the car a few week back and the only faults which came up were the electric window switches, 2 are faulty (which i knew about) nothing else showed up.
 
The way normally to test the vanes is to run from low revs in 3rd gear up to the redline (will need a Motorway slip road or dual cariageway) basically run from about 1.5K in 3rd all the way to the redline. Do that a few times and you should throw an overboost code (will know as it will drop into limp mode so pretty much no boost at all) if you have stick vanes.

Ran the Innotec through mine (75K now) and haven't been able to throw an overboost since. That, cleaning out my EGR and the Forge hoses have resulted in better MPG too.

Best to get a new exhaust gasket and clamp if you are going to clean the Turbo.

Paul
 
The way normally to test the vanes is to run from low revs in 3rd gear up to the redline (will need a Motorway slip road or dual cariageway) basically run from about 1.5K in 3rd all the way to the redline. Do that a few times and you should throw an overboost code (will know as it will drop into limp mode so pretty much no boost at all) if you have stick vanes.

Ran the Innotec through mine (75K now) and haven't been able to throw an overboost since. That, cleaning out my EGR and the Forge hoses have resulted in better MPG too.

Best to get a new exhaust gasket and clamp if you are going to clean the Turbo.

Paul

The car has never gone into limp mode since I've had the problem. I did give it a fair blasting down the M62 on the weekend, to clean the EGR valve out do you need to reset anything with VAG COM?

I'll bare the exhaust gasket in mind pal.
 
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The car has never gone into limp mode since I've had the problem. I did give it a fair blasting down the M62 on the weekend, to clean the EGR valve out do you need to reset anything with VAG COM?

I'll bare the exhaust gasket in mind pal.

Nothing in VCDS but it is best to replace the two o-ring seals (between the IMF and EGR / EGR and Inlet) and gasket between the EGR valve and pipe.

Paul
 
Does anyone know where to get these O rings from? My car is doing exactly the same as this iv just checked the O ring on the pipe going into EGR valve and its badly worn any help will be appreciated Thanks Alot. Scholey
Nothing in VCDS but it is best to replace the two o-ring seals (between the IMF and EGR / EGR and Inlet) and gasket between the EGR valve and pipe.

Paul