First truly stupid mistake sailing

[pnwsailor24]

So, it's been a little while since I took my boat out(a year), well, lo' and behold, I forgot to turn the saltwater valve on for the diesel....within a couple hundred yards outside the breakwater my engine compartment started billowing smoke, I turned my engine off and broke out the extinguisher....nothing was ablaze, but I had to run it again to get back home after I smoked it once(no wind, didnt feel like asking for a tow), but I didn't realize my folly until the drive home, when I was thinking about how I had checked all the fluids etc...."OH! The VALVE!". Needless to say, I was only more frustrated by figuring out what was wrong. So I drove back to the marina to redeem the day, turned the valve ON, and headed back out to sea, granted, the engine performed much better this time but it slowly started smoking again and I think my engine is making some new funny sounds, I didnt sinch down the radiator cap super tight, I thought maybe that was it(probably not).....I figured I'd give it a day or two to let her cool down before I tried to turn it back on, and then maybe magically everything will be just like it was before, I hear diesels are tough puppies, so Im hopeful, or is there a high possibility of a mechanic being needed? I know next to nothing about engines, and am basically just curious if other people have done a similar thing and what happened to them. Thanks!

[pnwsailor24]

Agh, I meant to post this in the diesel forum, sorry mods.

[sailingdog]

There's a very high possibility, almost a guarantee, that you did some damage by running it without cooling water for that long. You really need a mechanic to look over the engine and check for damage. At the very least, you'll want to replace your impeller, since it was run dry and is probably fried...

There is a reason so many sailors I know keep the ignition key on the seacock handle for the cooling system when the boat is not in use. It makes it pretty hard to forget to open the seacock.

I'd point out that you should have a checklist of things to do when starting up the boat or shutting it down, and that checklist can help prevent these types of mistakes. One simple check is to always watch for cooling water coming out of the exhaust before doing anything else, while the engine is idling. If the water doesn't appear to be flowing normally, shut everything down and take a look at what is going on. This is what I do on OPBs as well as my own, and it is a habit that has saved at least one or two engines from the type of damage you probably did to yours.

[knothead]

What did the smoke smell like? Was it oil? Rubber?

[scottyt]

as knot head said i would check for burnt rubber, ie an flexible lines in the exhaust system

[knothead]

Originally Posted by scottyt

as knot head said i would check for burnt rubber, ie an flexible lines in the exhaust system

Or belts.

[TQA]

Originally Posted by pnwsailor24

So, it's been a little while since I took my boat out(a year), well, lo' and behold, I forgot to turn the saltwater valve on for the diesel....within a couple hundred yards outside the breakwater my engine compartment started billowing smoke, I turned my engine off and broke out the extinguisher....nothing was ablaze, but I had to run it again to get back home after I smoked it once(no wind, didnt feel like asking for a tow), but I didn't realize my folly until the drive home, when I was thinking about how I had checked all the fluids etc...."OH! The VALVE!". Needless to say, I was only more frustrated by figuring out what was wrong. So I drove back to the marina to redeem the day, turned the valve ON, and headed back out to sea, granted, the engine performed much better this time but it slowly started smoking again and I think my engine is making some new funny sounds, I didnt sinch down the radiator cap super tight, I thought maybe that was it(probably not).....I figured I'd give it a day or two to let her cool down before I tried to turn it back on, and then maybe magically everything will be just like it was before, I hear diesels are tough puppies, so Im hopeful, or is there a high possibility of a mechanic being needed? I know next to nothing about engines, and am basically just curious if other people have done a similar thing and what happened to them. Thanks!

On starting the engine get into the habit of checking the oil pressure then looking at the exhaust and check for water expulsion.

The other thing is you need alarms for low oil pressure and overheating. There is a kit that is not expensive and MUCH less expensive than any engine rebuild. West Marine do one for about $50

Before you go to sea again run the engine and check the exhaust hoses VERY CAREFULLY esp om any bends close to the engine. You may have burnt through the hose.

[sailor50]

One easily forgotten thing, especially on old Yanmar diesels is the mixing elbow - this probably is not your problem - just wanted to remind others to check theirs.

[paul323]

Check the impeller - they often disintegrate if run dry. If you do find pieces missing from your impeller, find them - most likely they will have worked their way into the heat exchanger, but it is best to find 'em before they block something else and do more damage.

This is an awesome photo description on how to check and change an impeller:
Changing A Raw Water Pump Impeller Photo Gallery by Compass Marine at pbase.com

Could only take 20 minutes - takes longer on my engine because it is backwards...

[SteveInMD]

If you really got it hot (and it sounds like you did) you should also change the oil.

Hopefully the head isn't cracked. Keep a close eye on the coolant level for a while to make sure you aren't losing any.