Head Gasket? Need help

[MRover72]

So I was driving my SIII the other day and all of a sudden I had loud clunks in the engine and white and black smoke out of the exhaust. I figured it would be a blown head gasket, but found that hard to believe because the engine is a diesel and has under 50K miles. this happen to anyone before? thanks

matt

 

[81lm19]

When you heard the loud clunk did you have a sudden lose of power??
If so it was most likely a cloged injector clearing itself.
I had the same problem awhile back and traced it down to an injector.
Hope this helps