MTU 12V 2000 M94 Cylinder Head Gasket Failure

Have the coolant analyzed. Something maybe wrong with it, PH? It's about the only thing I can think of

Given the corrosion there is a good chance this was happening over time. Per Capt J it is localized to those 3 cylinders. It that area seal compression was lost. Either there was lack of compressive forces from manufacture or the compression was lost by an event'(s). Factory issues could be dimensional (head, block flatness, gasket thickness, etc) process related (bolt tightening) or material (bolt metallurgy, gasket defects, etc). Given it if seems likely event may have happened(ing) where excessive forces were created either stretching the bolts or deflecting the gasket/substrate. Could be coolant or combustion area related. Does that bank have it's own turbo and or cooling circuit, exhaust manifold, etc? What is common to those 3 cylinders?

Same here as Beau, my Man 820’s were re-torqued to spec at 400 hours as per the maintenance manual. I have seen quite a few engines list this including generators. I am not at all surprised with the need to re-torque them at this point based on the initial run-in; this is a good practice.

Wow lots of complicated theorizing. All for naught it seems. I'm with Soultice. The head bolts needed to be torque or replaced.

Just for the records, in the meantime I had a chance to check the MAN maintenance schedule, and I can also confirm that Beau was correct.
MAN indeed includes heads re-torque as a one-off activity, to be done on top of other M1...M5 service scheduled at 400 hours.

Can't see why MTU didn't do the same with their 183 series engines, whose M-B block was exactly the same as MAN.
But... Hey-ho!

So teach me here. That corrosion (looks pretty nasty to me?) encircles a coolant "hole, yes? If yes, why was oil leaking and not coolant.? Or is it an oil hole. Could it just have been a gasket failure/deterioration?

MTU just announced a new 2000 series engine version the 96X series starting with the 12V2000 96X

"The MTU high-performance yacht engine gets a power upgrade as the output of the 12-cylinder series 2000 M96 engine is increased from 1,432 kW to 1,472 kW, equivalent to more than 2,000 horsepower. Its proven acceleration characteristics, excellent maneuverability and quiet, smooth operation make the engine especially suited to luxury yachts and leisure fishing boats. This power increase means Rolls-Royce can now respond even better to customer requirements. The new engine version MTU 12V 2000 M96X is immediately available from now on".


First boats that are equipped with this new motors are a Viking sport fishing yacht and a OTAM 70. The 10 and 16 cyl. versions will follow ASAP.

That's one expensive piece of jewelry right there. Does anyone know what the expected fuel burn will be?

Probably around 160-170 GPH at 80% load for both engines.

According to the MTU engine manual app. 100 US Gal per hour per engine at rated power. They are not telling how they gaint the additional HP. They say the engine is not tuned up, only a fine tuned and optimized combustion process?

Sounds like better cylinder heads that flow more air.

And more fuel that's for sure. If those gph numbers are anywhere near stated. I had no idea that the 12's where sucking up that much fuel nowadays. My 1485hp are only pouring 100 gph at 80% for the pair

It's all in relation to HP. 1600 HP C32's burn 122 gph at 80%, 1900's are 168 GPH, 1800hp 16v2000s were 150 GPH.....2400 HP are 200 GPH......all at 80% load.

I agree, but everyone runs them at 80% load, so that's where the fuel numbers really matter to most people.......

Indeed. And amazingly, this rule of thumb which was valid 30 years ago still stands, with very tiny differences also in the most modern diesel engines.
Obviously, engine builders have been busier developing tricks to comply with emission regulations, more than anything else...