Sudden black smoke
 

Just got back from dropping son 2 at cubs in the 850Tdi CD Auto.

The turbo actuator vacuum pipes have just been replaced this morning, yet did not activate the turbo. I had replaced a couple around a month ago and found the others to be like chewing gum, so replaced the others this morning. However, the turbo boost did not return. Until this evening when I couldn't believe to power. It was like never before. I was delighted.

Then, without warning there was a 'puff' sound, then the exhaust note changed to a deep burble and clouds of black smoke. Fine when driven carefully, but terrible when under moderate acceleration.

Now Lambda light on. No obvious fluid leaks, smells under the bonnet. Acceleration fine. But, there is no way that will pass its MOT next week.

Any ideas very welcome.

Here is a clip my [YOUTUBE]https://youtu.be/NySzi9KVKqs[/YOUTUBE]

You've popped a boost hose somewhere. Happened me when got our V70 in September. It turned out to be the top hose where it enters the intercooler but check all of yours. You may not have tightened one of yours correctly so just inspect them again.

The bottom pipe under the engine, running compressed air from the compressor to the intercooler inlet stub, has a couple of stub hoses that are permanently wet with oil, and therefore rot over time. If you cannot find anything up top, or smell anything, it could well be the connections at the bottom.

Failing that, you will need a careful listen around the intercooler itself to hear for any air leaks. Most garages have a leak-test machine of some description or another; I have a "Smoke Pro" machine that emits lots of smoke for this sort of leak detection. It might pay you to borrow the services of a local garage if you are struggling, as they can often find this sort of thing in minutes.

Don't rule-out that the boost actuator might be sticking or incorrectly plumbed, as there is usually a reason for the intercooler circuit to fail......

Sorted
 

Well, thank you both very much. I can't thank you enough...

It turned out that my quick inspection at the side of the road had missed the top intercooler pipe having come off. The deep growling noise was obviously induction noise rather than anything more sinister.

Connected it back up (clip poor) and after clearing the smoke with a quick blast, all is now well again.

I have spent all night thinking it was terminal, and how irritated I was that I missed out on a lovely 960 on Ebay the other week.

Now I'm going to relax all day!

What a wonderful forum this is.

Excellent! Glad you got sorted!

Here's a pic of my top hose which blew in spectacular fashion