Need advice please lost compression in cylinders 4 to 6

[ShayMk]

Figured it out. Thanks

[Dragon Humper]

If the turbines are chewed up then that means whatever it was, it went through the whole rear system. If you are lucky you may be able to hone out the damage enough to re-use the pistons (if the skirts aren't chewed up too much). Because the engine is relitively new, you can open up the bores a bit and still be within clearance specs. One thing you can do is use pistons 4,5 and 6 in holes 1,2 and 3 to keep damage interaction to a minimum. If the builder did his job all the piston assemblies should weigh the same.

Bottom line is...she needs a full teardown and post mortem to see if it can be saved with minimal work.



Jon.

[Skym]

The intercooler usually catches foreign object's before entering engine. Check inlet side of intercooler and you might find what caused it, if something went through there.

If they are stock turbo's, sometimes the ceramic exhaust wheels can fail (shaft goes off balance, exhaust wheel hits housing and shatters) and some ceramic dust reenters the engine via exhaust valves (backing off throttle when exhaust wheel fails) and scores the bores. Rare to see, but does happen. Usually the ceramic exhaust wheel ends up in the middle of exhaust under full throttle.

By what you have described, sounds like the rear turbo exhaust wheel failed. I think it's rebuild time again and don't use stock turbo's again, buy N1 turbo's with steel exhaust wheels or equivalent sized aftermarket turbo's with steel exhaust wheels.