MTU 8V's ???

I am not an MTU expert by a long long shot... but here is my suggestion.

Your regular Cummins guy or really any good diesel mechanic or even you should be able to remover the injectors and reinstall... and bleed the system as those are routine maintenance operations.

First, because of the knock issue and you don't want to run the engines to warm up... Borescope the cylinders. See my posts on the Cat C-18 engine rebuild... here are the links

These are done by a very professional service tech by the way...!
This one is a borescope looky see of a C18
Marine engine inside - YouTube

This is the above C18 from borescope check through rebuild
CAT C18 Rebuilding ~ Réfection moteur CAT C18 - YouTube

This is a 3406... which has dropped a valve
Amazing Engine Inside (What's wrong doctor?) - YouTube


Second, while you got the borescope out then borescope the crankcase. This way you can see the underside of the pistons for cracks not visible from the top, cylinders to check for scoring not visible from the top, and for other obvious issues.

These should indicate if the engines have a serious mechanical problem that should be corrected before being run again. If everything looks ok then I would...

Third, if everything appears good to a professional doing the scoping then do both a leak down and compression test. But note leak down and compression tests really should be done on warm motors but you can do on cold motor in a pinch to get ball park because you already got the injectors out.

It does sound like a bad injector washed out a cylinder liner. Anytime you have an injector issue change it immediately. But this may not necessarily be the case. I have been running a set of 8v183's for a few years now and we put a good amount of hours on them (300 in 2 years) at cruise. They're kind of a pain to work on, but not very complicated motors. They're pretty much the same as 12v183's. Anyone familiar with diesel engines should be able to work on them. They're also similar Mans in many ways. First thing I'd have all of the injectors taken out, then turn the motor over and see if there's anything (fuel/water/etc) in any of the cylinders, then bore scope them. I had a similar issue with one knocking a little at idle, putting it in gear etc, and it turned out one of the nuts that tightens a fuel line to the injector was split.

Sailboaters hate all engines. It's in the oath they take. Well, except when it gets them in......so sort of love/hate relationships.

Post your questions on boatdiesel.com especially asking for an MTU mechanic reference in your locale.

Under 1000 rpms they're stinky, not really very smokey except on startup and for the first 15-20 minutes. It's just the way they are, you could try changing injector/nozzles......all of the fuel metering is done at the high pressure pump. I manage the yacht that has them. They run smooth at cruise and the yacht I run with them likes to cruise at 2000 rpms and burns just under 65gph (both at that speed). They should go 5-6000 hrs before a major. Keep a good eye on the exhaust manifolds as they used rubber-like o-rings to seal where the exhaust manifold meets the cylinder heads and they all started leaking and we had to yank the exhaust off and change them. There has to be a local guy that is familiar with them......

Hi,

The MTU 183 Engines are actually Mercedes industrial/automotive engines that have been marinised and had their branding changed to MTU.

A lot used to be done by Wiesmann Marine in Stuttgart before MTU got fully involved in them.

A capable mechanic who is experienced with any hi speed 4 stroke diesel engines should be able to do a compression test and remove , rebuild, refit the cylinder heads if required on these engines.

A chipped exhaust valve will normally give a distinct popping sound in the exhaust and an increase in white smoke will probably be evident caused by a reduction in the compression to ignite the fuel charge.

A faulty injector that cracks off at too low a pressure or does not atomise properly can lead to the cyl line being hit with wet fuel and a subsequent breakdown in the lubrication film, this can cause pitons to pick up ( melt through friction)

It may be worth a call to Tom Hug, MR Power. Since MR = Middle River, he's right in your neighborhood. He really knows his stuff. You can find his info in Google, or PM me and I will give you his #.

If I may ask, where did you take her for Winter?

J&T has always had a Baltimore branch:

500 Wilson Point Road
Baltimore, MD 21220
410-687-0500
800-479-3677 Parts
410-687-5137 Fax