Every marine engine case study on this page is a real vessel we worked on here in South Florida — a real symptom, a real diagnosis, and what it took to make the engine right. As the authorized MAN and John Deere dealer for the region, we read engines with factory diagnostic tools and factory data — often the difference between finding the true cause and simply replacing parts and hoping the problem goes away.
We document these marine engine case studies for a reason. A boat owner deciding whether to trust a shop, a captain weighing a major repair quote, a yacht manager protecting a warranty, or a surveyor checking an engine’s history all benefit from seeing exactly how a problem was diagnosed and resolved — not a marketing claim, but the actual work. Each study below walks through the vessel and engine, the symptom the owner reported, what the evidence showed, the root cause, and the outcome. Where another shop had already been involved, we describe what was done and what the data revealed, without naming names.
If your MAN or John Deere engine has you chasing the same problem, or you’ve been handed a major repair quote you want confirmed before you spend on it, these are the kinds of problems we solve every week.
Marine Engine Case Studies — MAN & John Deere
How a Misdiagnosed MAN V12-1800 Ended in a Seized Engine. A coolant-pressure alarm on a 72-foot motoryacht was diagnosed as a head-gasket failure, and the cylinder heads were replaced. The alarm returned within an hour, coolant reached the oil, and the engine seized. The real cause was a failing coolant pump — a fault a full-system diagnosis catches at the first alarm.
Coolant Alarm on a MAN R6-800 Traced to a Cracked Turbocharger Housing. A 44-foot Riva had a coolant-pressure alarm that new expansion-tank caps didn’t fix. From experience with the R6 platform, we went straight to the turbocharger — and found the cracked, coolant-cooled housing that was bleeding the pressure.
Considering a Major Repair?
Before you authorize an expensive repair — or if you’ve already replaced parts and the problem keeps coming back — get a second opinion from an authorized MAN and John Deere dealer. We review the symptoms, the service history and the diagnostic data, and we read the engine with the factory tools an independent shop usually can’t access.