Back From The Brink | Hydrolocking Our Thornycroft Engine

There are certain things you never want to hear. Like when you're wiping crumbs off of your shirt and someone shrieks:

"Who ate the last chocolate chip cookie?"

Or when you hear your mother scream up the stairs using your full name:

"Mary Jane Thomas, get down here right this minute and explain the bruise on your little brother's forehead!"

Or when you start the engine on your sailboat and hear:

"Ka-thunk."

As soon as you hear that sound you feel sick to your stomach. That's because it's the unmistakable sound that occurs when your engine seizes. That can result when you hydrolock your engine. I don't know much about boats, but I do know one thing - hydrolocking your engine is never a good thing.

If you don't know much about boats, hydrolocking your engine means that water has gotten into your engine. If you want to get technical about it, water gets into the cylinders which causes your pistons to not be able to complete their rotation. This causes your engine to stop. It can also cause significant damage such as bent or broken rods, blown head gasket, cracked cylinders or cracked block. That kind of thing.

For those of you who aren't into the technical detail, I'll translate. It means that everything is [insert your favorite naughty word].

After your stomach starts to settle down a bit and you've had a very large gin and tonic to calm your nerves, you start to assess the damage this is going to do to your savings account. We're talking big numbers here, at least they're big numbers to us. Potentially something in the order of $10,000. 

Actually, we're probably talking something like $10,250. The extra $250 is for additional gin and chocolate chip cookies. These will be required if you have to repower your engine.

"Repower" sounds innocuous enough. Kind of like eating an energy bar when your stomach starts growling.

What it really means is that you have to buy a new engine. Not only is that expensive, it would be a huge setback to us in terms of our cruising plans.

Besides, I've kind of grown fond of our Thornycroft engine. Sure, he's a bit rough around the edges and snarls at you when you change his glow plugs, but he's got an eccentric quality to him that's kind of endearing.

[Note: Scott just read this and asked me why our engine is a boy. I told him it's because Thorny smells bad.]

Thorny, our eccentric British engine.

Because we didn't have our engine in gear at the time, we had a small glimmer of hope that there might not have been any damage and that Thorny would continue to be part of our crew.

Turns out that we were lucky, which is why this blog post is entitled "Back from the Brink" and not "Goodbye, Savings Account."

Some of you nerdy boatie people are dying to know how the whole hydrolocking thing happened. You're weird, by the way. Turns out I'm kind of weird too because I'm writing blog posts about hydrolocking engines. How did that happen?

It was our exhaust elbow. It gave up on life and water backed into the engine. Fortunately, a spare exhaust elbow, gasket and end cap had just arrived from the UK the day before, so we were able to change it out.

Brand new exhaust elbow imported from England.

We administered TLC to Thorny by removing the glow plugs and draining the water from the cylinders. Then we ended up changing the oil ten times. Luckily, there was only a bit of water in the oil. Thorny really didn't like all of the oil changes. It's kind of like forcing a five year old boy to take ten baths in a row after he's been playing in the mud all day long. There's a lot of whining and screaming going on.

Finally, we got the oil looking the way oil should look - brown, somewhat clear and quickly turning to black. Not the unpleasant gray quality it had when there was water in it.

After that ordeal, here's the sound you do want to hear as Thorny starts up:

"Purr."

We definitely hope we dodged a big bullet here and that Thorny continues to purr when we head off to the Bahamas.

Have you ever hear a noise that made you feel sick to your stomach? What bullets have you dodged?

Thanks for stopping by our blog - we love it when people come visit! We're also on Facebook - pop by and say hi!