Attention Gear Heads. Hydrolock

[joe255558]

It's still under warranty and at the dealer. They said they cannot turn the engine over and that water was in all cylinders.

[AsLan7]

It's still under warranty and at the dealer. They said they cannot turn the engine over and that water was in all cylinders.

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I see a new engine in your future.

That being said, I hope VP and Cobalt can figure out the circumstances causing these hydro-locked motors.

[d47m122]

Hi all- this just happened to me as well. I have a 2019 Cobalt R7 with a 380 Volvo. We took it out on the lake the day before, no issues, no waves over the top of our boat, nothing out of the ordinary. We pulled up to our dock, they pulled it out of the water and put it into the rack. We came back the next day, and the engine wouldn't start. Initially I thought my battery had died so they jumped us and we tried a couple times to start. Then the starter began smoking and we stopped. Seattle Boat just told me that the engine is hydrolocked, it needs to be drained, spark plugs replaced, and that trying to start it hydrolocked destroyed the starter which also has to be replaced.

Anyone have any suggestions for me? I am trying to understand how a nearly brand new boat spontaneously hydrolocks. We did absolutely nothing out of the ordinary. Seattle Boat said this can happen if a "big wave" hits the boat with the engine off. It will not be covered as warranty as it's a customer issue. I'm up to $1600 so far in repairs. More if they find anything else once they start working on it.

[Big Block Power]

All I can say is let it idle before you go up on the lift. I still say it hairball the way you come off plane and shut it down. Keep pressure on VP and Cobalt. All I can say this sucks. I'm very careful on mine how I come off plane as it's known to happen.

[d47m122]

I guess maybe this is something that I don't understand about how to operate it. The way Lake Washington works and getting back to our storage rack, you come off any plane about 15-20 mins before you get back to the dock due to the no wake zone. When I come off plane, I never just chop back to idle and always slowly back off. But after doing so, the engine is running around 1500-1800 RPM until I get back to the dock. At the dock, I sometimes have to pop in and out of forward/reverse/neutral to get the boat to the dock. Other people can be waiting, need to get into the open section of the dock. Then once we tie up, I usually keep the engine running until I've raised the drive all the way up so they can fork it out. Only then do I shut down. I've done this dozens of times now with no issue.

All of this I would have to imagine is normal operation for the boat and the engine. What, if anything, am I doing wrong here? Is it possible that when they fork my boat in/out that they tilt the stern too much and water gets in? Is that a thing too?

I'm trying to understand how the hell I prevent this from happening again.

[bruceb58]

You kind of half to experiment by watching the wake behind you. If you stop real fast that wake can slam into the back of your boat and overcome the pressure of the exhaust at idle. Its actually probably worse if you running along slower at a non planing speed and then abruptly cut throttle. If your boat is slipped, it can actually be caused by a neighbors boat if his propwash was severe enough and close enough to your boat.

The thing is, if you are idling in from a high speed run and in a no wake zone for awhile, you really should not have any water in your exhaust that would cause a hydrolock

[d47m122]

Thanks. That's what I've been trying to figure out -- is the hydrolock immediate or something that can happen later? If it happened due to my driving, it would be immediate, right? The engine would just die upon water getting into it? That never happened. I never chop the throttle so the water spills up on the boat or the transom. That's not how we drive and we've never towed anyone. Coming back into my dock there was nothing wrong with the boat. We docked, the engine was running for a minute or two while we tied up and I raised the outdrive, then I switched it off. When we came back, boom, hydrolock.

Is it really this easy for a Cobalt to hydrolock? Do I need to plan for one of these a year? Sorry, still trying to wrap my head around this.

[AsLan7]

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Heyd47. Sorry to hear about your Cobalt woes. And no it should not be easy to hydrolock a Cobalt. It really surprises me this is happening. Personally I’d be going up the chain at SBC & Cobalt…especially when Seattle BC put it on the rack.

Keep us posted and welcome aboard.

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[tbully]

Hi df47. Sorry you're experiencing this. I'm here as both moral support and to learn as we have the same setup.

One thing I'll comment on is "drive all the way up...and then shut down". I've always been told that this is tough on the gimbal bearing and u-joint going to the outdrive. Totally from memory, I think the manual says something like, "do not run engine above 40%". Truthfully, I'll idle mine a little higher at times if in shallow water (gotta love SE Michigan and waist-deep water!) but avoid it otherwise.

Keeping the drive down, shutting down the engine, and then raising should not cause water ingestion.

Keep us updated. Other than the starter, I hope you'll be able to flush it and get back on the water.

[Holy Smokes]

This shouldn't be a problem for a 2 yr old boat, but I once had a failure on an exhaust riser gasket that allowed water to leak back into an open cylinder and caused a hydrolock condition. Gasket failure at that age would surely be a warranty covered item.

[d47m122]

Thanks everyone for the feedback. I have emails out to the dealer, Cobalt, and Volvo Penta. Cobalt responded this morning asking if my dealer had reached out to Volvo. Will keep everyone posted.

[Matts19]

Just a complete shot in the dark.....but does the fork lift back up a hill to the storage shed? Is it possible trimming the drive and having the boat be at a forward angle as it comes out of the water be enough to flow back into the cylinders? Not that this should be able to happen, but just a thought.

[bruceb58]

Just a complete shot in the dark.....but does the fork lift back up a hill to the storage shed? Is it possible trimming the drive and having the boat be at a forward angle as it comes out of the water be enough to flow back into the cylinders? Not that this should be able to happen, but just a thought.

I guess its possible but most of the water should flow out of the idle relief holes

[d47m122]

It's a flat dock. There aren't any hills. Unless one of the drivers was being a lead foot with the marina bull truck. And to what bruceb58 just said, I would have to assume that once the boat is out of the water, any water in the system would drain out. So that pretty much leaves when the boat was put back into the water the next day. Is it possible that they just tipped it back somehow and caused water to slosh in?

At any rate. The dealer says they are now pursuing a warranty with Volvo and repairs should be complete tomorrow provided there isn't any other damage in the engine. Will have to see how that goes.

I will keep searching for a root cause for this so it doesn't happen again in a week/month/year.

[tbully]

I think that assumption is plausible. Sliding it in the water too quickly makes some sense. Do you have Captains Call?