Catalac 12m Yanmar 3HM Cold Start, No Preheater/Glow-Plug

[KnightSail]

Hello,
I have a Catalac 12m with two Yanmar 3HM diesel engines. During this past winter we had trouble starting the engines in cold ambient temps. A new crew member who is new to boating but has extensive experience with diesel engines on shore was shocked to discover the Yanmar 3HM does not have a preheater/glow-plug, and he says that all diesel engines do/should have one. I'm pretty sure these engines were original equipment installed by Tom Lack, so I'm guessing that other Catalacs have them as well. I wrote to Yanmar and their response is that the 3HM doesn't need a preheater/glow-plug, which made my diesel crewman chuckle.
All research into an aftermarket/add-on preheater kit has come up empty.
This vessel spent most of her life in the Caribbean basin and Florida, but her future will likely be in colder climates.
Does anyone have any info/experience with this problem, and hopefully a solution, please?

[Jeannius]

Not all diesel engines require glow plugs but the vast majority do have them fitted. If Yanmar say they weren't fitted to that engine then I imagine it was originally a very high compression engine and that your engines have lost some of that compression. Turbo diesels will all have glow plugs - or some other heating system - as they are lower compression by design. I've heard stories of people whose glow plugs have failed using a hair drier or a blow torch directed down the air intake and that being enough to get them started.

[KnightSail]

Not all diesel engines require glow plugs but the vast majority do have them fitted. If Yanmar say they weren't fitted to that engine then I imagine it was originally a very high compression engine and that your engines have lost some of that compression. Turbo diesels will all have glow plugs - or some other heating system - as they are lower compression by design. I've heard stories of people whose glow plugs have failed using a hair drier or a blow torch directed down the air intake and that being enough to get them started.

Thank you very much for your assistance, Jeannius.

[Baste]

I have two old Volvo Penta MD7A diesel engines in my 9m. There is no pre-heater on them and I haven't heard that any of the early small VP diesels have pre-heating. One of them is hard to start at low temperatures, like 5-10 degrees celcius, but starts fine at 15-20 degrees. Putting an electric heater in the engine compartment for a few minutes when it is cold solves the problem. I checked compression on both engines and this one has less compression than the one that always starts easy in all temperatures. I would suggest you check compression.