OK advice on Turbo now fitted :-)

Darnun72

Firstly thanks everyone for your advice on the previous thread I created regarding my turbo for my A3. Actually assisted me in how I approached the garage and I actually got a good deal to be fair.

So, the garage stripped down everything to do with the turbo - All pipes, induction, intercooler, even the rocker cover and all fully cleaned out again and nothing was found that is classed as debris.
All fitted back with new turbo.

The old turbo is going back to the supplier and they are doing a full warranty report on it where it tells you what the cause was to kill it (eg impact damage, overspeed etc)

Now on to the car. The one overwhelming thing that has stuck out through all of this is the whistle. That noise you get when you rev before changing gear. It has now become almost a paranoia for me.
When I drive the car now, as I rev to approximately 1800 - 2100 revs, I get a whistle sound from the engine and then as I change gear and let the clutch off it goes and you hear the excess air being let out the turbo gate.
So my question is: is this normal in some cars or is this just the precursor to the thing going again. I am getting mixed opinions from places I read.
At this moment, it's not loud loud but I can hear it (probably down to me listening out for it too) but this is what happened last week. The whistle was there and all of a sudden got louder and it was then I got the AA to take it to the garage where we found the turbo had gone again.

Seriously stressed when I drive the car now, as you can imagine. Is this whistle normal in turbos?

Retrogamer

You can have turbo whistle and turbo whine,but both are two different things.
Turbo whistle is normal and you hear it at different levels on different cars.
Turbo whine is bad and is the sign of a dying turbo.

Since they never found any debris i think we can rule out debris being the cause of the turbo failure.

I suspect the original turbo didn't get enough oil going to it. This caused the bearing to run dry and become damaged and this creates the whining noise.
When the bearing fails, the turbo blades can wobble about a lot and hit the turbo housing.
This causes the blades to break up and give the impression that something has hit them such as a bolt.

When you put the new turbo on, the same thing happened.

The turbocharger is fed with oil via oil feed pipes. If the car has not been serviced correctly then the oil may sludge up in the pipes blocking oil feeding to the turbo.

I suspect the oil feed pipes may be blocked and this is what has caused the second turbo to fail so quickly as well and if they weren't changed recently potentially the one fitted now.

It's not always the case but it's common. The garage might not have primed the turbo bearing with oil as well prior to fitting causing premature failure.

Darnun72

Wow thank you for that response. I will check with the garage to see if they did that very thing. I do know that they told me, when the first one blew that it left lots of oil in the pipes, more than usual so you may be on to something.

Darnun72

OK waiting for the garage to call me back but I do know that they did a test after putting both turbos that showed the flow of oil...If this is what you mean then may be it is ok.
Also, when I called him yesterday mentioning the whistle he said it it's indicative of overspeed but they took the car out on the road and hooked up the computer and it showed no overspeed.
Confused.com

OddballJamie

What sort of mileage has the car done?

Darnun72

A3 1.9TDI and it's done 90K

OddballJamie

Darnun72 wrote: »

A3 1.9TDI and it's done 90K

Pretty low then. I was expecting closer to 200k.

Darnun72

Exactly....When the turbo gets back to the supplier tomorrow, they will be able to ascertain exactly what caused it to die.
I have been told that the turbo kicks in around 1800 - 2500 revs and that is exactly when I get the whistling so it may be natural turbo whistle and nothing to worry about.
Some forums say whistling is normal, others are adamant it's a bad sign and should be looked at. If I am brutally honest, I don't know the difference between a whistle or a whine LOL

Retrogamer

I have a 1.9TDi as well but in an Ibiza.
I have a pretty loud turbo whistle but that's due to performance parts fitted. I can't remember if it had one as standard.

Do you know what bhp model yours is, or it uses a KKK or Garrett Turbo?

Darnun72

Garret Turbo I believe and don't quote me but I think it's 140BHP

colino

With yet another turbo change, you did change the oil and filter didn't you? Or at least analyse it.