How to make your Diesel last a long time.

[Chuck Baier]

hellosailor, you have an echo. I wish we could travel 1000 miles in 10 hours. More like 60 to 75 miles in a ten hour period then add about 1/4 of a quart of oil. Actually after running for 2 1/2 days we added just over a half a quart so no rhyme or reason.

[Ex-Calif]

Originally Posted by Chuck Baier

ten hour period then add about 1/4 of a quart of oil. Actually after running for 2 1/2 days we added just over a half a quart so no rhyme or reason.

Well it's not leaking and it's disappearing. Not to state the obvious but it has to be burning. That means valve guides or rings. No magic.

With the age of the engine I'd say rings. If the consumption is not consistent that is perplexing. Sorry to be a stickler about the measuring units but you really can't mix days with hours and pints and quarts.

Unless of course you mean

8 ounces in 10 hours and
16 ounces in 60 hours (2 1/2 days)

Sorry to be a pinhead about this.

[hellosailor]

Chuck-
I think you've got Dan & I both confused about how much got burned up how fast. But if it is that inconsistant...that IS odd. Time to speak to Yanmar and do some testing, I guess. If the load and engine speed were consistant--the consumption should be. Any chance there was a serious change in speed or wx that could account for a changing load being part of that?

[Chuck Baier]

Dan, You have the quantities down right. I have considered valve guides and even possibly rings but this engine was installed in this boat as a repower and was brand new. The vanishing oil has been since day one and every Yanmar mechanic at the beginning said this would quit once the rings seated. Could they possibly not be seated after 1200 hours. We have maintained the engine operated it since day one.

[Chuck Baier]

8 ounces in 10 hours and
16 ounces in 60 hours (2 1/2 days)

This is the correct amount being consumed and not exact. Might be a bit less or more but pretty close. No change in weather, speed, sea conditions or anything else. None of these factors change the oil consumption. we have motored in flat seas, motorsailed in moderate conditions and pushed hard in near gale force conditions and the consumption is usually pretty close to the same. I guess my only issue with the oil being burned is this engine shows NO smoke or any kind of soot on the stern.

[Alan Wheeler]

What oil quality are you using?? Cheap oil can be used up faster than a good quality. Although I assume you are using a good quality seeing as it is you Chuck.
Here is a good question though, Do you notice if consumption increases toward the end part of it's service life. Dirty Oil can cause it to be burnt faster. I have often noted that an engine can use little oil and then suddenly the oil use increases and I realise the change time has arrived.
Leaky valve guides produce quantities of blue smoke at certain points of operation. The main one being startup. I doubt this will be the issue at such a low eng hr. Most likely she is still bedding in, although this should have happend by now and I go back to my original comment. However, I do not consider this quantity of oil being used as exccesive enough to worry about the engine not having bedded in correctly. I think you will have many years of good work and reliability ahead.

[Chuck Baier]

Thanks Alan. We use a good quality oil and the lack of any smoke is one of the mysteries. There is no difference in consumption whether it is the day after an oil change or as she approaches 100 hours. I am not too concerned since it has performed so well for us. Just thought maybe someone had a clue that we had not considered. After virtually tens of thousands of miles I am not going to get too worked up about it.

[hellosailor]

Chuck, my only concern would be whether it could be something significant, i.e. if the oil was being pulled past the beginnings of a head gasket failure--only when the engine was at a certain operating temperature, etc. Or into/through some other odd way, due to thermal changes.

[hellosailor]

I see I have an echo again...and this time, I KNOW I only hit the "post reply" button once.

[Nauticatarcher]

From my Fishing Days, an Oil burn rate of 1% of fuel consumption was OK, oils cheap, unnecessary overhauls aren,t

[Alan Wheeler]

Hey Nauticatarcher, great to see you here. How's sunny Nelson???
I finaly got around to actually installing the VHF last weekend. I just down loaded the instructions and am reading them. Hmmm, complex little beast eh.

[Ex-Calif]

Well all the questions are asked I think. I too don't consider the consumption to be "significant" although I'd keep watching.

Bedding of the rings (properly or not) would be my wildest guess followed by Oil ring alignment at assembly. There are obviously end gaps on the rings and they should be staggered from each other during assy.

Very very rarely the assembler may not get this quite right. It usually shows up as big blowby and bad compression from day one.

It sounds like you are running the engine hard which is a good thing and with no other mysteries to report I'd drive on till something changes.

The only other thought is that it might consume a larger amount during warm up and basically nothing once thermally stablized. That could explain the variation in consumption for 10 hours vs. 60 hours. The lack of smoke is perplexing but again we are talking about pretty low consumption.

[Chuck Baier]

Thanks everybody for your input.