Oil Change Basic Question

[jbox84126]

Hey folks,

I bought a Hunter 33.5 and am working on the first oil change of its Yanmar 3GM30F. I've tried a couple different dipstick pumps (manual and electric) and only been to get about 1L of the engine's 2.6L capacity out of the sump. The engine has been at operating temps for all these attempts.

Any suggestions for basic things that one could be doing wrong and causing the oil not to flow through the pump?

Thx jon!

[chris mac]

I have the same engine. I use a vacuum assisted pump and find it have to really play with how deep the tube is and what direction the curve of the tube goes. There seems to be several pockets of oil, so it takes a little time to find them all.
Like everything sailboat related, time and patience wins the day

[DoubleD]

Ditto to what Chris said. I also have a 3GM30F and started with the dip stick tube to far in.


DD

[Lepke]

Sometime in the future when the oil is drained, replace the pan drain plug with a pan valve and attach a tube to match your pump. Then you get every drop.
Use a long tube and when not in use attach it high above the pan so if the valve fails, your oil doesn't run out.

[wsmurdoch]

I don't think the Yanmar 3GM30F has a drain plug in the oil pan. I know that my 3HM35F does not.

[rpackard]

On my Yanmar 2GM I use a rigid brass tube connected to a hose. The tube goes right to the bottom.

[Scubaseas]

Try sucking it out just via the dipstick tube. My 4JH engine works this way and I'm pretty sure most Yanmars do also. The dipstick tube goes all the way down.

[wsmurdoch]

I use a rigid dip tube to suck the oil out. To speed the removal of the oil, the pickup tube needs to be as large in ID as will easily fit through the dip stick hole. 3/8 OD tubing is just a little tight. 11/32 OD is perfect. The hardware store near my house keeps a collection of thin wall brass tubing that comes in diameter increments of 1/32. I have also seen it in hobby/model stores. To fit 1/2 inch hose to the tubing, I cut the hose barb off a brass hose to NPT adaptor, slid it over the tube, and soldered it in place. I trimmed the tube to a length that will just reach the bottom of the oil pan and make a satisfying clink when it drops into place.

[Idaho]

First, just stop thinking about wasting oil and money.

Warm the engine then use whatever method you like to remove as much oil as possible. Then remove and drain the oil filter. Refill it with cheap oil.

Refill engine to spec with cheap oil. Warm the engine again. Again remove as much oil as you can. Replace the oil filter with a new one, fill it with cheap oil and screw it on.

Again refill with cheap oil, warm and drain as before.

Do this as many times as it takes until you throw away golden, clean, cheap oil.

Then put on a new filter and fill the engine to spec with the most expensive, full synthetic oil you can find.

Your next oil change will be at around 500 hours of running time.

[noelex 77]

Originally Posted by jbox84126

Any suggestions for basic things that one could be doing wrong and causing the oil not to flow through the pump?

Remove the oil fill cap so air can enter to replace the volume of oil sucked out.

[boatpoker]

Originally Posted by Lepke

Sometime in the future when the oil is drained, replace the pan drain plug with a pan valve and attach a tube to match your pump. Then you get every drop.
Use a long tube and when not in use attach it high above the pan so if the valve fails, your oil doesn't run out.

and to that we added a $24 12vdc fuel pump from Harbour Freight and pump out every last drop in about 2 minutes.

[GreenWave]

Originally Posted by Idaho

First, just stop thinking about wasting oil and money.

Warm the engine then use whatever method you like to remove as much oil as possible. Then remove and drain the oil filter. Refill it with cheap oil.

Refill engine to spec with cheap oil. Warm the engine again. Again remove as much oil as you can. Replace the oil filter with a new one, fill it with cheap oil and screw it on.

Again refill with cheap oil, warm and drain as before.

Do this as many times as it takes until you throw away golden, clean, cheap oil.

Then put on a new filter and fill the engine to spec with the most expensive, full synthetic oil you can find.

Your next oil change will be at around 500 hours of running time.

Wow - not very environmentally friendly.

[Scubaseas]

Originally Posted by Idaho

First, just stop thinking about wasting oil and money.

Warm the engine then use whatever method you like to remove as much oil as possible. Then remove and drain the oil filter. Refill it with cheap oil.

Refill engine to spec with cheap oil. Warm the engine again. Again remove as much oil as you can. Replace the oil filter with a new one, fill it with cheap oil and screw it on.

Again refill with cheap oil, warm and drain as before.

Do this as many times as it takes until you throw away golden, clean, cheap oil.

Then put on a new filter and fill the engine to spec with the most expensive, full synthetic oil you can find.

Your next oil change will be at around 500 hours of running time.

Um, no? Why would you do this? There will always be oil left over in the engine. Most engines hold about a quart more of oil after rebuilds which is to say about a quart stays in the nooks and crannies inside the engine. Why would I want to replace the quart of residual good synthetic oil I use with a quart of cheap stuff? If I'm using good synthetic oil why does it have to be the most expensive oil I can find as opposed to what is spec'd for the engine? Instead of wasting oil on trying to get the residual oil clean just buy a decent filter and decent oil. Oil's supposed to get dirty especially on a diesel. And FRAM is not a decent filter just IMHO. Please enlighten me.

[wsmurdoch]

I follow Yanmar's oil change intervals and just drain and refill. I do change the filter every time because it is easy and inexpensive.

Originally Posted by Scubaseas

...FRAM is not a decent filter just IMHO. Please enlighten me.

I called Fram and asked them for their equivalent to the Yanmar 124085-35170 that my 3HM35F uses. They said a Fram PH5046. I found them at Tractor Supply. Practical Sailor ran an article on oil filters (https://www.practical-sailor.com/sys...omparison-test) where they said, "Fram The end caps were made of a weak cardboard-like material. Often the end cap material was crumbing, and in several cases, was tearing loose from the ends of the media. These same failures have been reported in the automotive press. Bottom line: Fram filters are not recommended." Worried, I cut one open with a Dremel grinder. It looked nothing like the filter they described. Looking back at the article I see that they looked at 4 used Fram filters two of which were part number PH3378A, a part number that I could not locate, and the part number of another was unknown.

[Cheechako]

If it's a vacuum style hand pump unit, warm the engine first. I use one often. The tips on getting the tube inside the right amount is the key also. You can hear the gurgle if it is in too far or too short.

I had an installed electric oil pump on the sump on one boat. It worked well, but between valves and hoses and oil drips I really wasn't that fond of it. One problem was the tubing stayed attached to the valve (which the sump tube went to) . So now you have to store it attached in the boat without it dripping a mess. You have to pump the used oil into a separate container also. All this was messy and troublesome down in the engine room. I guess I needed enough room and a bracket to hold the used oil container.

I bought the hand vacuum unit and it was actually easier and much cleaner, stores the oil right in it!!