Turbocharger Problem

Sounds like the waste gate got stuck in to closed of a position and the hot gasses melted the fins. This would have created a large amount of suction on the filter if it was dirty and the high pressure in the system may have created other problems. Better check your valves.

Looks like a complete strip down of your heads, and while you're there, check your timing.

I don't know about AUTO SYNCHRONISED, can one DG over rev and not the others?

If the engine over rev ed high enough to melt the turbo and collapse the air filter you will need to check more than the heads. A teaspoon of dust is all it takes to wear one out. The crank, con rods, pistons and rings will also have had some serious stress and heat.

A stuck open exhaust valve can cook a turbo but would not collapse an air filter.

A stuck open intake valve could damage the air filter.

If these VOLVO PENTA have electronic heads (no cam) a possible brain fart but not likely.

without seeing it in the detail the exact cause is hard to pin down.

hope this is of some help

Brad

As I previously stated above the air filter damage collapse or whatever it may have been is directly related to over rev's of the turbo. When a waste gate gets stuck in the flowthrough direction of the turbo and if the filter is even remotely dirty, it can be "Sucked in" from the additional draw created by the over rev situation.

I have personally seen a turbo setup that the over rev collapsed the entire airbox. This happens when there is not enough airflow coming into the airbox itself to accomodate the additional air being drawn through the turbo to be compressed.

Had the guest said everything else was fine but the turbo melted down then I would have suggested the fuel mix had gotten to rich somehow and post combustion detonation would have been the culprit.

More Information is always useful and a picture is still worth at least a thousand words. So if the guest is still monitoring this post then it would be helpful to gleam a bit more information on the situation.

thanks for ur interest. i'll try to arrange some pics . may be in a day or two