Chipper.chica

Thanks guys! Should I just let the mechanic put his oil in? or is there a brand you know of that would be best? Should I check with the mechanic that he is going to use mineral oil?

Hello! Warning: If you are a seasoned boater who knows their way around an engine, you may find your eyes rolling at my ineptitude. All I can say is I'm trying and want to know more, before you say google it... I did but I'm struggling to make heads or tails of it. Background: diesel, Vetus M3.10 engine, 37ft boat, looks like the engine had it's first 50 running hours 1987. Myself: Had the boat 6 months, never touched an engine before her, currently racking up my call outs with RCR. I've managed to get the RCR mechanic to go through a service with me and he's going to talk me through how to do it myself, go through the whole maintenance schedule! Brilliant. Problem, he said he can supply the oil but he's saying he's got 15w40 that he puts in. The original manual that I've found is stating the following: Engine Oil SAE 10w30, Mil-L-2104 C, CC-CD Not sure what 'Mil-L-2104 C, CC-CD' means but not sure that parts important. Please correct me and inform if it is very much important. It's given a list of examples, which are the following: Shell Rimula CT 10W30 Gulf Veritas SD 10W30 Esso Essolube D 3 10W30 Mobil Delvac 13 10W30 Chevron Delo Super 10W30 Every single one of those oils have been discontinued. I've gone onto Vetus' website and even they don't sell 10W30 for inboard apparently it's for 4 stroke 'outboard' engines, then again they have discontinued the M3.10 engine. Now possibly, it says in the manual 10W30 because other oils weren't really around. Maybe today we have a better oil for this type of engine, something that wasn't available 30-odd years ago. I'm very worried because she's an old engine and I really want to do the BEST for her, whatever it takes. Don't want to buy the cheapest alternative, want the best alternative.... also something I can get my hands on for this weekend 9/5/2020. I know! Perfect time to try and do an oil change but my alternator broke and so it's getting refurbed and the mechanic says he can talk me through a service at the same time he fixes my alternator... As I'm probably 50 running hours over the recommended running time before it needed another service (going off the manuals guide).... Whoops! Any suggestions? What type of oil? where can I get it? Somewhere online? If you can give me a bit of background info on why you suggest the oil, that would be really nice to know! Thanks for your help, advice or any offerings you can make!