Hi guys,

I have recently purchased a 2005 Audi A4 2.0 TDI and my turbo broke just after about 100 km of driving. This is how it happened:

Moments after I started the engine, a red oil pressure light came up on the dashboard. I stopped the engine immediately and called the service (not an authorized Audi service though). People from the service shop called me back the next day and told me that they've replaced oil sensor and everything is fine now. I picked up my car and about 200 meters away from the service I noticed a huge smoke cloud coming out of the exhaust pipe. I also noticed decreased engine power. This time the oil pressure light was not showing up on the dashboard. I stopped the engine immediately and called an authorized Audi service. They checked the car and told me that my turbo is broke.

Since I don’t understand much in engines and how cars operate in general, I would be grateful if any of you would suggest what could have been the cause of the failure. I understand from reading about this issue that it’s crucial to find out the root of the problem so that it doesn’t repeat itself.


Thanks!

 

well one way they can break is overheating, that is most common cause.. Also if they aren't cooled down after heavy use.. reason why they make turbo timers.. quikly cooling metal is definitely gonna mess it up usually warped or simply cracked. Also the bearings wear out faster, which in turn just cause more heat.. As for the smoke cloud it prolly was a result of your engine running insanely rich since the air pressure wasn't there, too much fuel little air.. The good news is, if you can find a good used or new stock turbo or one that directly bolts up it isn't that hard a swap. I've never done it on an audi but done it countless times on DSM's, basically takes patience, some wrenching and busted knuckles.. One route you can take is go to a junkyard and find a stock turbo, the only problem is if you don't know how to tell if a turbo is good you might get a bad one. Another way they can go bad, though not common is a really hot turbo getting soaking wet.. I've only seen this from retards that race their car everywhere then decide to clean their engine bays with a hose.. cracks manifolds, ruins turbo's just not a good thing. now if your oil sensor was bad, and there wasn't enough oil circulating through the turbo (i'm assuming they are oil cooled i am new to audi's) that could in turn heat the turbo resulting to break. Soo it might of very well been the oil sensor.. anyway hope this helps, anyone feel free to correct anything in my post, like I said i'm new to audi's still learning.

 

I agree with the oil theory considering you were having issues with it right before your turbo went ka-put...These turbos are oil cooled and need the proper cooling time (or oil running through for that matter) for them to operate correctly. You can avoid this in the future by maintaining your maintenance schedule for your car and doing proper checks often to insure that your car is running well. These cars are not cheap or easy to maintain, but that's not why we have them in the first place I'm assuming this car was used, so you don't know what kind of hell the previous owner had put this car through. Look in the Noob section about FAQ and maintenance tips for your specific car. It will guide you in the right direction about proper care, preventative maintenance, and the steps to comeplete most things in your garage (DIY). Good luck, brother

 

Thanks both for the reply.

Yes, I have learned this lesson the hard way.

Just so you know, the official response from the garage was that the failure came because the oil sensor failed and somehow oil went directly to turbine's air flow passage, which, in turn , sent oil (instead of air) to the engine and caused the white smoke out of the exhaust. The oil that flowed in the turbine caused it to break. ?!

 

something about what they said, just isn't making any sense.. They said an oil sensor failed sending oil into the turbo housing which in turn put oil into the cylinders through the intake, and that is what caused the white smoke..?

First off burning oil does not cause white smoke, that is caused by condensation evaporating, for example on a cold day when you first start your car up you will see white smoke from the exhaust heating up and evaporating the water condensed in the exhaust system. Burning of oil will cause a darker cloud of smoke almost with a blueish tint to it if seen in the right light. Also the burning of coolant will smell kinda sweet if I'm not mistaken, where as the burning of oil is distinguishable. Hard to describe that smell but you will know the difference..

Another way to get white smoke is burning of coolant.. That is a tell tale sign if your car is warmed up and you see white smoke.. This means either a gasket is leaking somewhere or a few other things but the main point is coolant is getting into the cylinders..

Anyway I dunno about this mechanic and what he is telling you. I don't see how a sensor failing redirects the flow of oil somewhere else, unless someone can clarify this for me.. BTW are the turbos on the A4 only oil cooled or water cooled? If they are water cooled which i'm assuming, might of gotten a leak from the hose running to the turbo which in turn sent it into your cylinders, that to me sounds more logical then that mechanics oil theory...

 

I am pretty sure from what i've read so far that turbos in a4 are oil cooled.

The first sign that the cpu reportet was the red oil pressure sign on the dashboard. Then the turbo broke.

Frankly, I dont believe my mechanic about his theory either, but it kind a made sense because the failure had to do something with oil because there was almost no oil in the oil tank when mechanic first inspected it...almost all the oil went directly to engine.

Now that the turbo is replaced everything is working fine.