Turbo seal oil leak

[tjmoody]

It looks like I have a turbo seal oil leak on the RH engine. Initially it was thought to be the gasket for the oil return line but that did not resolve the problem and now we are seeing oil in the compressed air pipe going to the intercooler ... not good.

We are waiting for options from Diamond but I'd appreciate if any one can share any similar experiences. Is this a replacement or repair scenario for the turbo?

AE300 TT ~500hrs

Thanks,

Trevor

[Soareyes]

Glomming on to your question here. My 2020 DA42 has had three annuals now. The first annual they completely replaced both turbos. The second and third annuals they fixed turbo oil leaks, something to do with “Banjo fittings” on both engines, both times. I hadn’t noticed any operational problems. I remove the cowlings occasionally and hadn’t noticed any leakages.

How did your oil leak manifest itself? How bad is it to see oil in the compressed air manifold? Not supposed to be there but what is the risk, fire? Power loss?

[tjmoody]

Thanks Dan. Initially I noticed a little oil coating on the nacelle behind the air outlet next to the turbo. After taking the cowling off, I saw oil around the oil return line coming off the turbo. My shop replaced the gasket and all appeared ok after a ground runup. But after a short flight back to my home airport, the oil had reappeared. Suspecting a crack in the oil line, the shop replaced the line. This time it also looked good on the ground but after a short flight, there was more oil around the turbo and now staining the compressed air pipe. See attached picture. The shop's conclusion is that the turbo seal has given way which makes sense to me. We are waiting feedback from Diamond on what my options are.

There was no impact on performance and no indication on engine instruments. I've no idea what the risks are but the plane is AOG now. I assume turbo failure would have been the next step. I've read about a potential turbo diesel overrun scenario which is a rare condition where oil exiting the turbo can provide enough fuel for the engine to overspeed uncontrollability. Even if the regular fuel is cut off, the leaking oil can maintain combustion. It doesn't end well. There are some dramatic videos on Youtube. No idea if this is a possibility with Austro engines. I've never heard of such a situation in an Austro.

I'll share more as I get updates.