Missus driving home from work in a seat leon tdi. Loud bang, black smoke out the back, car limps over to the hard shoulder. AA speculated it was a broken turbo. Car still starts and can be driven into a parking space.

Don’t know much about cars; what’s a broken turbo and how much to put it right? Thanks.

Im NOT a mechanic but I wouldnt drive it an inch more. Not even start. Im just worried about oil/oil pressure- thats probably nothing to do with the turbo but that bang could mean anything at this stage IMO. All the best.

Could just be a pipe blown off.

Sounds like a blown turbo yep. Probably what’s happened is that one of the oil seals inside the turbo has failed, allowing engine oil to escape into the exhaust gas stream. The burning oil in the exhaust system causes the black smoke.

A turbo is a device that uses the energy in the exhust gases to squeeze more air into the engine. More air means you can inject more fuel and so produce more power per revolution.

Unfortunatley, turbochargers are precision instruments and so expensive. They’re not as stupendously expensive to replace as they used to be (grand a piece), but they’re still a nasty shock. I reckon you may be still be looking at £4-500 to recondition your current one and refit it.

Don’t drive it. Bits of broken turbo can find their way to places they oughn’t be. If you are lucky it won’t be difficult to access the turbo – on my old car (Audi S4) it was an engine out job and £3k)

Burning oil in the exhaust causes whitey-blue smoke, not black. What is more likely to be happening is your ECU is fueling for more air than is being present due to a knackered turbo, this will produce black smoke on a D. Here is a prime example of oil burning in the exhaust side turbine:
http://www.youtube.com/watch?v=cufnsBzb_wQ
That was peeing oil into the exhaust side, I know because I autopsied the turbo about a month later when I replaced it 🙂

Dont drive it. At all. If the turbine shaft has snapped you’re going to have degraded oil pressure across the engine and have bits of turbo floating around the intake, ready to be sucked through the engine.

Fortunately TDi turbos tend to be cheaper than performance petrol ones. Expect a garage bill for around a grand for it and labour though. Do it yourself with a second hand turbo for ~2-300 if you have the spanner skills.

However it is worth getting it looked at in more detail. My brothers 330d just did effectively the exact same thing and on opening the bonnet, the plastic manifold had split open down its seams. This would produce the exact same symptoms.

Can you still hear the turbo whistling when revved (dont do it any more!) as it did before, or is it accompanied by rattles and screaches or silence?

Nope….99% sure it’s not blown turbo.

I would (almost) eat my hat if it’s not just a boost pipe come popped off. You lose boost, power & get in return an absolute gob of black smoke from the exhaust.
It happened to me in my Ibiza TDi. Turned out one of the original clips that holds the pipes together wasn’t the correct type.
In the Ibiza, the pipes have little metal ‘ears’ that the clips go round to hold them in place. When the pipes blow, generally the ‘ears’ bend or break off, so you’ll probably need it replacing.

EDIT – having now read coffeeking’s post above, I am even more convinced that it’s the pipe, rather than the turbo. You get all the black soot coming out as the ecu thinks a certain amount of air is going into the cylinders, but downstream of the sensor you’ve got a leak (pipe popped off) so it’s being over-fuelled. New pipe on mine was £45, but it was one of the shorter lengths.

I had this on my old golf gt tdi.

The clips that secured the pipe into the intercooler used to be made from plastic & under heavy boost used to fail & the pipe would dislodge slightly causing all the problems you state.

Very rare for modern tubos to fail (unless starved of oil) so I agree and say it will be a split/dislodged pipe.

Good luck

The old style pipes from the intercooler are carp. My petrol Octavia vRS blew its off when I gave it some beans on the first day of owning it 😆 VAG have a new modified pipe so it shouldn't happen again.

the PD engine is a classic for blowing off boost pipes as stumpy01 says (work in "car industry") that engine was fitted to golfs, skoda's, audi's etc.

seen a lot with leaking pipes. normally turbo's don't go bang.. it's the pipes as the clips fail or come off as the compressed air is released.

failed turbo's result in white/blue exhaust not black, black is poor mix of fuel/air commonly from leaking boost pipes..

find a recommended (by someone on the Seat forum say) garage… would guess £50 for the pipe plus time finding it.

worse case the turbo was gone 4-500 for a turbo dynamics recon excellent guys fast and well known in the VAG community.

It turned out to be a pipe blown off, as people said. Clip had sprung off. Thank God for that!

Told ya 😀 Made me soil my pants when it happened 😆 Well maybe not literally.

Good to hear the cheaper option was true, for once. I did think it was highly unlikely to have failed, normally they dont fail catastrophically without warning you beforehand (screeches etc).

Something similar has just happened with my Golf TDi – fingers crossed it's just the pipe!