Hydrolock Water Intrusion...

[RonnieQ]

Re: Hydrolock Water Intrusion...

That was my brothers explanation also (also a mech) and I tend to always believe him. I never put the 2 events together, until when I called the marina we bought the UsedBoat at, they made a comment about another boat having the same problem that day, that it backfired, sucked water thru the exhaust, and hydrolocked.... They got the water out and back on their way.... That's when I said "hmmmmmmmmmm"..... and of course after I had already torn into the riser's looking for leaks......
So I am praying now that we just got water in the wrong way and everything else is ok..... and we will be back on our way soon..... and with a little more knowledge.... Thanks !!!!!

 

[Maclin]

Re: Hydrolock Water Intrusion...

When the engine diesels, it is fireing off of hot spots spots in the cylinder head, piston, carbon, etc. The ignition can occur long before the piston reaches near top dead center, causing the engine to reverse direction. Many times when an engine diesels, it will initially be rotating in the correct direction, but just before it stops, it will reverse for a half, full, or sometimes more rotations. The reverse rotation causes the exhaust to act like an intake, sucking in exhaust gas and water.

This is good info John. The engine can actually rock back and forth in both directions. It almost certainly will not actually run in reverse but does get kicked back hard enough to turn backwards as you mentioned, and can do this a few times forward then reverse and that is it, the damage is done.

 

[RonnieQ]

Re: Hydrolock Water Intrusion...

Compression test checks out ok... Don't have the tool yet to do a LeakDown test, but am going to put all back together and try to get it running with WaterMuffs and see what happens... Plan on running it for awhile and then pull the plugs and check... Good plan? Anything else I should consider...

 

[RonnieQ]

Re: Hydrolock Water Intrusion...

Just got everything installed back correctly last night. I replaced with New rider gaskets. Here is my plan for tonight: 1. Hook up watermuffs 2. turnover without plugs 3. check cylinders for water 4. if ok, put plugs in 5. try to get started and run for a few minutes 6. Let sit a couple minutes 7. pull plugs and check cylinders for water 8. if ok, add plugs and run for awhile until normal operating temp 9. pull plugs and check again 10. if ok, the maybe problem solved 11. If NOT, then must be headgasket or worse and will then seek professional help...... Good plan?

 

[Maclin]

Re: Hydrolock Water Intrusion...

I do not see a need to turn it over on the starter with the plugs out and water running. I think that may actually try to let water in as the exhaust pulses will be very weak.

I think I would just hook it all up with water and start at your step 5...........

 

[RonnieQ]

Re: Hydrolock Water Intrusion...

I guess that would make sense... I am just nervous about it hydrolocking again.... I have gone thru the (very) painful process of extracting a broken starter bolt while stuck upside down in a hole where the battery goes twice now.... Don't want to have to do that again
It should be fine now though because everything is dry and lubricated...

 

[RonnieQ]

Re: Hydrolock Water Intrusion...

By the way DonS... sorry about the finger...

 

[Maclin]

Re: Hydrolock Water Intrusion...

It probably would not ingest enough water during starting and running to lock up unless there was a major rupture or hole or something way wrong with the exhaust manifold or riser plumbing or gasketing.

 

[RonnieQ]

Re: Hydrolock Water Intrusion...

Thank you to all who have helped !!!
I ran several tests in the yard consisting of running on muffs for awhile, pulling plugs and checking for water.... Dry as a bone !!!
Took it to the lake for true test yesterday.... ran WOT for a bit, shutdown, let sit for a few minutes and then pulled plugs.... Still dry !!
Conclusion? Either riser gaskets had leaked(I installed new ones) or dieseling sucked water in.... Boat ran great rest of the day !
I know now where to come for answers.... Thanks again !

 

[Maclin]

Re: Hydrolock Water Intrusion...

I like endings like that