How Often to Start a Diesel Engine?

[barnakiel]

If a boat is tied to the dock (not meant to go sailing in foreseeable future) and if her owner does not want her engine winterized, then how often should the engine be started and how hard should it be run?

To say: if not actually used for motoring, what is the optimum diesel starting regime/schedule?

-once a week, just start it?
-once a week, run it hot?
-a different schedule?

And why?

b.

[TeddyDiver]

Once a year in warm and dry climate, cold or moist much more..

[cfarrar]

I'm not diesel mechanic, B, but I'd say there's no perfect solution. If you don't run it, it sits and gradually accumulates some corrosion. If you run it in neutral at the dock it's not great for compression, and it won't get up to internal operating temps. On the other hand, it's a diesel. It will probably be fine.

If it's going to sit for a long time, why not change the oil and run fresh water through the raw water side of the heat exchanger? In less than an hour you'll have peace of mind that you've done your best to forestall internal corrosion.

Now it's time for a real mechanic to weigh in....

[barnakiel]

Originally Posted by cfarrar

(...) If it's going to sit for a long time, why not change the oil and run fresh water through the raw water side of the heat exchanger?(...)

Because the owner wants the boat to be ready to go at any moment - without having to open the raw water intake, removing the rags from the air intake, etc..

When we leave her behind, we winterize. But when we live aboard, I want the boat to be in actual ready-to-go condition.

b.

[S/V Illusion]

Originally Posted by barnakiel

Because the owner wants the boat to be ready to go at any moment - without having to open the raw water intake, removing the rags from the air intake, etc..

When we leave her behind, we winterize. But when we live aboard, I want the boat to be in actual ready-to-go condition.

b.

A winterized engine Is ready to go (but protected from freezing). To -"unwinterize", just open the seacock and start it assuming the belts are tight and the impeller is in. Just curious - How long does it take to remove a rag?

Sarcasm aside, periodically starting an engine for a few minutes does more damage than good. If someone is too busy/preoccupied/lazy to do it properly, I doubt he will get much empathy from everyone else.

[sy_gilana]

Onan manual says Two weeks if not winterized. Detroit once a month. I go every 2 weeks on both.

[denverd0n]

Originally Posted by barnakiel

-once a week, just start it?
-once a week, run it hot?
-a different schedule?

Just starting once a week it is a REALLY bad idea! If you start it at all then run it long enough to get it warmed up. Once a week is probably more often than necessary. I would do what others have suggested, and put it up so that it can sit for as long as it needs to, but if you really, REALLY don't want to do that then my advice would be to start it once a month, run it until it is fully up to operating temperature, and then another 10-15 minutes after that.

[roverhi]

Because my bpat was 2,000 miles away, trips to it were relatively infrequent, maybe 4 times a year at the least. It was 6 years or so of that infrequent running and it's still doing fine. I would either take the boat out or at a minimum run it in reverse or forward in the slip for a minimum of 30 minutes. You not only need to get the engine thorougly warmed up but also run it long enough for any water or other liquids to evaporate off.

[Cheechako]

Starting every couple of weeks would be good. At least monthly. Put it in gear and run it for long enough to good and hot. You need to cook the moisture and acids out.

[Redcoat]

And don't forget to clean your antisiphon valve at least once a year. To guard against hydrolock.

[thinwater]

When I run an engine at the dock, for maintenance purposes or to test after adjustments/repair, I run it in gear at cruising throttle for about 10 minutes. If the dock and lines can't easily manage that load, then they won't handle a storm either. Idle simply doesn't prove anything or get the engine to full temperature. Any shorter time period is not going to pull fuel through all of the lines and the filter.

If the slip were very shallow I might have second thoughts about kicking mud, but this shouldn't be a problem if there are a few feet. If I were concerned or if the prop cavitated, I would not throttle up quite so far.

[DeepFrz]

I think once a week is not too often. And I think it needs to be run at about cruising throttle (in gear) or slightly less (work up slowly) for a minimum of 20 minutes. You need to get the oil up to operating temp and keep it there for at least 10 minutes, IMHO.

[SabreKai]

That's my method as well. Leave her tied to the dock. Start and run up in drive. Work the beasty

[David M]

You want to keep oil on the walls of the internal parts. S0 the longer you wait the more chance there is of the engine seizing or rust forming causing it to score the walls and bearings. I think don't wait more than a month.

[belizesailor]

Related question: Lets say your engine has not been started for 7 months. What would you do to minimize potential issues when starting for the first time?

I ask, because I have recently been informed that the bone-head who was supposed to be tending to my boat has apparently not even set foot aboard since July.

My plan so far is to fog the cylinders, turn over slowly by hand a few times to spread some lubrication around and (hopefully) fire it up. Other suggestions?