A3 2.0 tdi loud bang and white smoke

[daveyboy.c]

Hi there,
my wife was driving home Friday night and she heard a loud bang :sign_omg: and lost 90% power. She said the noise came from the back of the car. We did drive the car home but it was crawling along. When I tried it on Saturday morning it starts fine but is blowing some white smoke (turbo?) and if I try and hold the revs at 2000 rpm it stutters. I only bought it in January but the dealer is being vague about my 'comprehensive' warrantee .I live in Swansea and travelled to Swindon to buy the car from what looked like a reputable dealer. I am not very good with engines and would appreciate any advice/help..... also any suggestions of where to take it in Swansea if it is the turbo...... thanks

 

[mjr901]

check intercooler hoses, quite common to blow off.

 

[daveyboy.c]

would that cause the loud bang?

 

[mjr901]

would that cause the loud bang?

Yup - they literally 'blow off' causing instant power loss.

But 2.0 TDI could well mean turbo, but you need to start at the cheaper end of the scale.

Turbos tend to give you plenty of warning with siren noises, they're not usually a sudden 'bang'.

 

[daveyboy.c]

I did have a quiet siren but thought that was normal

 

[Best84]

Exactly the same thing happened when my other half was driving mine last year. Turned out to be intercooler hose, the clips wear down (Crappy design imo)

 

[mjr901]

I did have a quiet siren but thought that was normal

A degree of turbo whistle is normal.

If you can accelerate/decelerate gradually and almost mimick the sound of a police cars siren, then it is pooped.

My money is on the intercooler hose being at fault.

Happens time and time again. Not expensive.

 

[daveyboy.c]

Just started it up and I can't hear the turbo at all, it does sound like air is blowing somewhere.... being Wales it is chucking it down at the moment so not the best time to pop the bonnet

 

[mjr901]

Just started it up and I can't hear the turbo at all, it does sound like air is blowing somewhere.... being Wales it is chucking it down at the moment so not the best time to pop the bonnet

The amount of intercooler seals I sell at work for these things is ridiculous.

If this is the problem, upgrade to forge items with better couplings.

Edit** for A3 140 see below.

Forge Motorsport | Alloy Fabrication

Buy new seals from Audi to go with them.

 

[daveyboy.c]

Thank you for all your help 'mjr'.... much appreciated, let's hope it is the hose and I will upgrade if it is

 

[SmithyAG]

When my turbo went there was no bang at all, just sudden power loss and lots of smoke.

When I was fixing a boost leak after the new turbo was fitted, I hadn't put one of the intercooler pipes back on properly and when it popped off it went with a proper bang, car was driveable at really low speed but try and drive normally and it would surge and smoke, as the turbo was just blowing into the atmosphere effectively.

My money's on a boost hose has popped off too, hopefully for you it is as it's far cheaper than a new turbo!

 

[T8DPR]

OP, dealer can be as vague as he wants but the LAW dictates he's responsible to rectify problems occuring within the first 6 months of ownership

 

[smurfworth]

You wouldn't have white smoke if a turbo hose blew off though, it'd be black and lots of it.

White smoke normally relates to water. Why you'd have heard a bang though I've no idea.

 

[Ron burgundy]

I gave DIY a go today and changed the seals and clips on the pipe work that goes to the intercooler, and like a numpty I didn't put the clip on properly on one if the pipes that goes directly on to the intercooler

so when I drove down the road I also got the Big Bang noise ha and the pipe came straight off ,

All sorted now but im there was no smoke when it popped off.

 

[SmithyAG]

You wouldn't have white smoke if a turbo hose blew off though, it'd be black and lots of it.

White smoke normally relates to water. Why you'd have heard a bang though I've no idea.

Quite right, Forgot to put in my post, when the hose blew off the smoke was black, due to fuelling with no boost. When turbo blew it was white as the oil burned.

 

[daveyboy.c]

there is no smoke when idling, only if I rev the engine but not masses of it also my wife said the bang came from the back of the car.... she thought a rear tyre had exploded!!

 

[welshd1k]

id say intercooler pipe . mine did this 2 weeks ago get under it and look and you 100% its white not a dark grey ?

 

[daveyboy.c]

turned out to be the hose after all.. didn't think I would be that lucky.... I can see why others said it is a poor design. I am going to upgrade the hoses now that I have seen it first hand. Apart from the 'Forge' hoses are there any others that you guys recommend? I really like this car and don't mind upgrading the turbo, intercooler, exhaust etc.. I think I got the S line 'bug' and I want my other half to stop telling me we should have bought a beamer

 

[welshd1k]

forge is the cheapest the fittings are £18 each(cheapest I can find) plus hose etc

 

[max69vk]

Have you got a 140 or 170? If you've got a 170, Forge stopped making hose kits for them so the only other options will be custom made or a Darkside hard pipe kit, which isn't cheap!