3gm30 Yanmar full of hose water....

[Dave in Eugene]

so...there I was ... starting my engine for the 1st time in 2 years!...thought I would make sure it was going to cool well and hooked up the garden hose to the water pump....

Filled the engine right up....

pulled the injectors...turned it over a bunch...blew in a big amount of wd 40.... and will try and start it with a bucket of water with a hose from the water pump...

Any thoughts or "you might want to considers" before i try to light the fire...

Will change the oil once I've run it for 10 minutes.

Thanks and happy what-ever-you-are-into...

Dave

[never monday]

run it for 30 min. it should be fine.

[Ex-Calif]

OK - Assuming you attached a pressure hose to the raw water inlet and subsequently filled the exhaust box, then backflowed through the exhaust manifold past the valves and into the cylinders?

How is the oil level? Overfull? i.e. is there water in the sump? I would drain the sump first. Heating the oil with significant amount of water in it could create a bit of a mess. Also if it's sat for a while the oil and water could separate - the oil will float on top and the oil pickup will suck up water for a while.

Stick your garden hose in a bucket and turn it on. Connect a hose to the inlet of the raw water pump and dip it in teh bucket as well. Make sure the pump doesn't have to lift it from the ground all the way to the engine if on the hard, though. That's a big lift for a thrash pump. Put the bucket in the cockpit or something. Let the bucket overflow so there is always supply to the raw water pickup.

[Dave in Eugene]

Will check the oil level and run the hose from the cockpit. Thanks for the thoughts! Dave

[Dave in Eugene]

Any thoughts on oil brand and weight...looks like the book calls for between 20-40 wt. Thanks... dk

[never monday]

Originally Posted by Dave in Eugene

Any thoughts on oil brand and weight...looks like the book calls for between 20-40 wt. Thanks... dk

Lets start this this way....

In my opinion.
There are only 3 oils to run. Oil weight will depend on your climate. 30w for warm tropical climes. 15w40 for mid climes.
Shell Rotella T
Mobil Delvac
Chevron Delo 400

[Dave in Eugene]

engine running! Happy guy...thanks

dk

[sildene]

Dave, glad you had a happy ending. Hope you don't mind if I try to understand how the water actually got into the cylinders. Did you actually start and run the engine with the garden hose plugged in, or did the water simply pass the water pump (and impeller blades?) while the engine was stationary?

If you actually ran the engine, do you know why the lift muffler did not exhaust the water via the outboard exhaust as per usual?

Martin

[Dave in Eugene]

The engine was not running. I turned the water pump by hand and it rushed by the pump. I think there was significant water pressure on the hose.

Can you explain why there is a difference between the engine running and not in this circumstance? Thanks

[never monday]

Originally Posted by Dave in Eugene

The engine was not running. I turned the water pump by hand and it rushed by the pump. I think there was significant water pressure on the hose.

Can you explain why there is a difference between the engine running and not in this circumstance? Thanks

The raw water enters the exhaust stream at the injection elbow. From there it goes to the water lift muffler. If you don't have exhaust gas pressure pushing the water up hill it will back flow into the next highest point, The engine. Before flowing to the exhaust outlet which is likely 12+" above the engine.
Your hose water is running about 35psi normally. This is enough to flood a non running engine in just a few min.

[Dave in Eugene]

...and boy did it... Learned a lot from this experience and was real glad to bow before the yanmar and get to know it. thanks again for you input.... I have a few more questions brewing. dk

[Badsanta]

I would check and replace the raw water impeller. It may be worn or broken allowing the water to flow past

[Dave in Eugene]

thanks..the impeller is in good shape and we are packing new spares.

Dave

[jrd22]

The 3gm30 (and maybe others, all Yanmars?) will fill with water if you run the starter for prolonged times and the engine does not start. Like when you are bleeding the fuel system after changing filters (trust me on this). If you close the seacock to the engine while you are doing this it will prevent it. Make sure to open the seacock as soon as the engine fires.

John

[Maine Sail]

Dave,

Seems like you had to learn the hard way! Sorry about that..

I'm going to be blunt and to the point here so that it helps others!

NEVER, NEVER, NEVER, EVER CONNECT PRESSURIZED WATER OF ANY TYPE TO YOUR RAW WATER INTAKE ON THE ENGINE!!!

I tried to explain just that to one of those "new boat owners", who "knew it all", two years ago one Saturday at the yard, and he proceeded to total his engine within fifteen minutes of me trying to explain the reason for not hooking it up that way! Over the years I've seen or known of at least five engines destroyed in this fashion. Dave you got very lucky that your engine was NOT damaged.. The guy at the boat yard actually hydro-locked his and destroyed connecting rods and more. Either way my boat yard made about 12k on that guy... I offered him my 5 gal bucket but..............vroooom vroooom boom...

If you don't fill the muffler and back feed the engine that way the pressurized water will, in many if not most cases, blow by the seals in the water pump thus forcing water directly into the engine! This problem has NOTHING to do with your impeller and everything to do with how NOT to flush an engine or run an engine on the hard...

THE RAW WATER PUMP IS A PUMP AND IS NOT DESIGNED TO BE FORCE FED!!!


Sorry for the abrupt candor but folks need to understand this is NOT good for the engine and can cause catastrophic damage..