Engine oil change

[CCJ]

What sort of boat has he got?

Read "Most engines" that just about covers it

 

[RichardS]

I shall not be running it, I will change the oil cold.
You seem to be at variance with the other posters. I hope your good fortune continues. T.

It's been a long running debate on just about every engine forum since synthetic oil hit the consumer market in the 1970's.

I've just purchased 10 litres of 20W-50 synthetic oil to use in an engine that was designed in the 1950's and, with that oil in the engine, I would expect another 50 years of good service. The main problem with old engines is getting a synthetic oil of the right grade at a reasonable price. However, things are changing rapidly in that regard as synthetic oil becomes increasingly common.

Richarf

 

[PaulRainbow]

You miss the point. Yanmar specifically outlaw the use of synthetic in the handbook.

Can't find any mention of this in my Yanmar manual for the Ops engine, can you point me to where this information can be found please ?

 

[peteK]

I have a yanmar 3gm30f and I need to change the oil and filter again (I used synthetic oil when I did the change at layup). The boat is out of the water and I am wondering if the closed freshwater circuit will be enough to protect the engine if I run it to warm the oil prior to extraction. I would leave the saltwater pump inactive unless I have to arrange a cooling water supply.
Could this damage any other engine component.
TIA. T.

Wouldn't say go ahead and run it but I did this for about 10 mins without any water pumping through too the exhaust,just removed the impeller and kept checking how hot it was getting.

 

[lpdsn]

I shall not be running it, I will change the oil cold.

That's just making life harder for yourself. The synthetic oil may or may not have a cumulative effect on the engine over many years of usage, you can see there are posters on both sides of the debate, but you only need 10 or 15 minutes to warm up the oil for extraction.