Problems with Turbo Engine of Audi TT 1.8L 2005 150BHP

Question

I bought this car a couple of months ago and last month had a major issue, the car just stopped driving! I called the AA who told me it was the timing belt. I got towed back home and took it to my mechanic (thankfully my next door neighbour) and he fixed my car after about 3 weeks. I'm not too sure what he did, but he ordered a lot of new components including timing belt, valves, etc.

I've had the car back about a week and a half, and yesterday morning on my drive into work I noticed a weird high pitched "wooooooo" sound when accelerating, my wipers shut off mid wipe once, after being turned off/on this solved the issue. I called my mechanic as soon as I got to work who said he'd have a look at it on the weekend.

However, on my drive home from work - things took a turn for the worst. The 'wooooo' sound got much louder when accelerating and became very consistent and all of a sudden thick, grey/black smoke surrounded my car from my exhaust. Then the oil light appeared on my dash. I finished my drive back home (5 minutes away) and the smoke was unbelievable! Pretty bad!

I'm just wondering if anyone knows what the problem may be and how much it may cost to repair?

I have just paid £1,600 for the repairs by my mechanic :(

Any help would be appreciated!

Answer 1

Smoke emitted from the tailpipe is likely either coolant or, more likely given the oil light, engine oil. The "wooooo" noise you described is in all likelyhood a boost leak. The wipers stopping mid-wipe and then restarting is likely unrelated to the engine problem. I've had a Volkswagen group car do this to me once and it never did it again since.

I assume that, given the amount of money involved, that the mechanics work is warranted. The only slight issue may be that continuing to drive a car with a fault, especially when there is an oil-light on the dashboard, may invalidate any warranty.

Without seeing the car or diagnostics data from it, we could only guess at what the reason for the smoke could be. It may be that a gasket isn't sealed correctly or it may originate at the turbocharger.

Answer 2

From the description I'd suspect turbo failure.. and I'm sorry to say that if that's the case you're looking at another big bill.

Answer 3

What initially happened is that your timing belt broke, which causes the moving pistons in the engine to hit the -now stationary- valves in the engine head. This causes major engine damage and expensive repairs. This is also why it is important that a timing belt is to be replaced at a fixed interval, either after a certain mileage or age (x years).

What happened now is difficult to say exactly, but it sounds like a major oil leak somewhere in or around the engine. What is worse is that you should NEVER have continued to drive around with the oil light on. A yellow warning light on the dashboard means just that, but a red light means STOP NOW! Worst case scenario is that you have driven around for five minutes without any oil pressure and that your engine is toast. But that is something that needs to be determined by a mechanic and not by someone sitting behind a keyboard.

Answer 4

The 1.8T Audi TTs have what's called an "Interference Engine" (AKA Non-clearance engine). What this means is that the timing belt system will fall out of sync if the belt fails. However, when things fall out of sync, it also allows things like your cylinder head valves to hit the top of your pistons. More often than not, timing belt failure in these types of engines can cause catastrophic damage (bent, or what your case sounds like cracked pistons).

More info on failing timing belts in interference engines

With that out of the way, now you need to determine what all happened. So lets take a look at all your symptoms:

1. Car stopped suddenly: This is the result of the timing belt failing and your valves falling out of sync
2. Wipers stopped working: Normally this could be an electrical relay, but since starting/stopping them again fixed it, it's most likely related to the electronics system in the car
3. Woo coming from turbo: This is either a leak in your piping, or gaskets (mostly work on NA vehicles, so not very familiar with turbos).
4. Smoking from tail pipe: This could be from non-sealed gaskets
5. Oil Light: Most likely an oil leak

While I'm a huge fan of the idea of neighbors helping each other out, if your neighbor isn't a certified Audi tech, I'd recommend talking to an Audi maintenance person. You don't want to be throwing money at this car, without having it properly diagnosed.

Answer 5

Your car has experienced major damage. If your timing belt snaps while the engine is operating that means the pistons collide with the valves, which means major engine repairs. The mechanic must pull the head off the engine block and replace the valves and check that the pistons aren't too damaged. He must also correctly set engine timing and replace seals. The fact that you are seeing huge clouds of black smoke and the oil light is on, indicates you are leaking or burning oil. A whooshing sound when accelerating is normal in a turbocharged car. But a constant whine or similar could indicate the turbo bearings are not being lubricated properly--in the case of oil starvation from low oil.

Are you certain it was the oil light? If it is just the check engine light, there could be an issue with the vacuum lines which would cause the engine to run rich, which can also cause black clouds of smoke when accelerating (although you should not see smoke after the car is off).

Hopefully the mechanic that did the work, offers some sort of warranty on their work. Although, its up to them if they try to scam you into thinking it's an unrelated problem. This is most likely related to the work they did since valve replacement and timing are intensive jobs with lots of room for error.

I would check the oil level myself and look for soot accumulation (black soot) on the exhaust pipe. Fuel smoke tends to be black, whereas oil smoke tends to be bluish in color. These can help you gain more certainty on the actual problem.