Marine Oil Additives...??

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Ifraser

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Hi, I'm just about to complete the first 100 hrs on my mercruiser 1.7d engines. The manual calls for 15w40 oil and various gradings specs just like any car... but refers to oil required with Marine additives.. Does anyone know if these are really required or is it just another cunning plan to squeeze more money out of us boaters...? I'm guessing there is very little difference as to what goes on inside the engines than on a vauxhall Astra ( which is apparently the same engine..) I'm aware that the air that goes into the engine will be saltier than the astra's and it may work a bit harder but are there any experts who can say what these additives are supposed to do. My warranty has expired so no issues about that... thanks for any help... Iain..
 
You are quite correct in your assumption.

This was a little bit of Mercruiser Quicksilver marketing B.S.

A cooking 15W 40 to ACEA E5 will will likely have an additive pack superior to the Mercruiser own brand stuff. Like all manufacturers they tend to recommend not mandate their own stuff.

CMD re-wrote a whole heap of stuff when they inherited the engine. Particularly installation guidelines.

Rest easy, prop the motor light and check the wastegate actuator pre season and you will have no problems.
 
Thanks Lateboater that was what I was hoping to hear... as for the wastegate actuator I don't have seasons (as I stay in all year ) so will regularly check the actuator and am planning to install boost pressure guages, which I used to think were just toys, so I can quickly spot an actuator failure and consequent overboost... thanks again.. Iain
 
I looked into this recently. marine grade oils are different from normal car oils. I agree that your Astra diesel is essentially the same as a boat diesel. However the Astra probably gets driven and warmed through every day or more. Your boat engine spends a lot of time doing nothing in a damp atmosphere. Boat engines fail because of internal corrosion rather than wear. Diesel engine oil becomes acidic with use and corrodes the innards. So the reason i buy marine engine oil is to protect the engine when its NOT in use as well as running. (especially over the winter) Boat engines are very expensive - oil is relatively cheap even marine specced oil.
 
Where is the wastegate actuater, and what check do you recommend? I have 2 of these engines in my boat. I also have a difference in oil pressure. What do you normally see hot and cold? Stbd engine runs about 5 psi more than port.
 
Hi, rafiki... the wastegate actuator is,I think, somewhere up near the exhaust elbow. Have a look at this link to a ribnet discussion I think that shows where it is. http://rib.net/forum/showthread.php?t=19433
Apparently if these engines fail it is often due to the waste gate sticking open which over boosts the engine. That is why I will be fitting boost pressure guages when I get the chance. As for the oil pressure I can't help you there as I only have the basic dash panels with just rev counters and warninng lights for everything else.... cheers for now Iain
 
Thanks Iain,

I'll have a look at this at the weekend. My current use is on a river, so only using low power, so there is a good chance that the actuator could seize with lack of use.

This is the problem with forums, you only hear bad news!!!

Paul
 
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