Stupid mistake - overheating

[HalcyonS]

Hi all,
I had a bunch of new people on my boat today and what with one thing and another, forgot to open the raw water intake, till there was smoke in the engine compartment. I'm embarrassed and humbly accept your scorn.

In any case, I opened seacock and idled it for a while. No obvious crisis. It started and ran fine a few hours later. My question - what gets damaged in such an overheating scenario? I'm RWC and I have no idea how long its been since its been flushed. certainly over 10 years.
thx!

[ndutton]

Well, you'll beat yourself up worse than any of us will.

If it were me, I'd perform a cooling system pressure test straight away and if successful, change the oil and impeller. Other things to consider are exhaust system components that depend on cooling water for their survival, non-metallic waterlift (if present)and exhaust hose specifically.

Admirably, by your candor you have become the poster child for any of three levels of alarm system. With the basic Cole-Hersee system you would have had an alert as the temp rose above the trip point. Upgrade the basic system with the raw water flow sensor and you'd hear the buzzer within seconds of starting the engine long before the temps got out of hand. Go the full monty with the EWDS and you'd have a buzzer to get your attention and a green light identified 'FLOW' telling you raw water flow was the reason for the buzzer. Your experience is exactly why these systems were developed.

[Mermaidquest]

Exhaust Hose Failure

I am in the process of "Fixing" the damage from I believe the exact "oops" moment that you've described in this thread! I had a "Eureka!" moment last night while removing the exhaust hose from the hot section of my manifold. The relatively new hose had collapsed internally! There was no evidence what-so-ever that anything was wrong on the outside. This experience has led me to realize how wonderful having everyone's knowledge and experience at your fingertips on this forum. Thanks to you all,and a special THANK YOU to the person that originally posted that I should figure where was the HY2O coming from in the first place! My humble apologies for my smart- ass reply.It,s a Ranger thing.Ha

[smosher]

My Moments

I do turn on the water intake, but right above it is the gas valve and I regularly
forget to turn that on.

Steve

[hanleyclifford]

Early in my Atomic 4 life I had a similar experience. After restart I had a big leak from the Vetus water lock which I was able to repair with epoxy and bailing wire, and continue to march. However, you should know that often damage can occur internally (collapsed baffles) that may not be obvious. The good news is that frequently the water lock will take the beating and not transfer the heat to the exhaust hose (so readily) which is a much more difficult repair. Monitor your performance after the event closely in case you have such damage. + 1 on the flow sensor which I am incorporating into my exhaust system this year. BTW, I now carry a spare water lock.

[Dave Neptune]

About all that can really be damaged if the engine re-started and ran like NORMAL is the water pump impeller (very doubtful) or the plastic and rubber in the exhaust itself. If you were running easy there is probably no heat damage.

Just check for leaks and you probably will be fine. As far as the engine itself unless it seized temporarily or fully seized there is no internal damage.

Give the oil a good sniffing and if it smells burnt or odd change it before next use. The smokey engine box is normal when the engine gets hotter than normal and it is mostly the residues accumulated on the exhaust and the manifold that evaporate away causing many a nasty smell. What you don't want to smell is rubber or plastic having burnt which is probably going to be limited to the exhaust itself.

I sent you a PM (late) the other day. Did your buddy get the pump out of his Carter?

Dave Neptune

[joe_db]

I had someone do this on my boat. What got killed was the exhaust hose. It wasn't obvious at the time, but the interior was coming apart.

[HalcyonS]

I sent you a PM (late) the other day. Did your buddy get the pump out of his Carter?

Dave Neptune

Dave, no sign of a pm from you (I've been looking). Send again pls?

[HalcyonS]

About all that can really be damaged if the engine re-started and ran like NORMAL is the water pump impeller (very doubtful) or the plastic and rubber in the exhaust itself. If you were running easy there is probably no heat damage.

Just check for leaks and you probably will be fine. As far as the engine itself unless it seized temporarily or fully seized there is no internal damage.

Give the oil a good sniffing and if it smells burnt or odd change it before next use. The smokey engine box is normal when the engine gets hotter than normal and it is mostly the residues accumulated on the exhaust and the manifold that evaporate away causing many a nasty smell. What you don't want to smell is rubber or plastic having burnt which is probably going to be limited to the exhaust itself.

Dave Neptune

Thanks Dave, Neil, Hanley and all for quick response.

The engine did not seize - I idled it for a few minutes after getting water into it. Until the smoke cleared at least. To my nose it was burning-oil smoke, not burning rubber smoke. And cooling water seemed to be spurting out in more or less normal fashion. It did *seem* to have a new noise, a kind of low rattle, but I may have been imagining it. I checked the oil after, still full, didn't notice burnt smell but I'll check again. I'm due for an oil change anyway (not my favorite job). My exhaust is old, original afaik, and the original builder spared no expense. I'll monitor it.

None of this would have happened of course, if I hadn't observed the safety precaution of not opening raw water until the engine was running

[HalcyonS]

Admirably, by your candor you have become the poster child for any of three levels of alarm system. .

lucky me ! When is the photo shoot?

So what does a water/coolant flow sensor look like? And where would you put it - in a T in the cooling hose after the pump?

[joe_db]

Any time I have the raw water turned off I pull the coil wire out

Thanks Dave, Neil, Hanley and all for quick response.

The engine did not seize - I idled it for a few minutes after getting water into it. Until the smoke cleared at least. To my nose it was burning-oil smoke, not burning rubber smoke. And cooling water seemed to be spurting out in more or less normal fashion. It did *seem* to have a new noise, a kind of low rattle, but I may have been imagining it. I checked the oil after, still full, didn't notice burnt smell but I'll check again. I'm due for an oil change anyway (not my favorite job). My exhaust is old, original afaik, and the original builder spared no expense. I'll monitor it.

None of this would have happened of course, if I hadn't observed the safety precaution of not opening raw water until the engine was running

[hanleyclifford]

lucky me ! When is the photo shoot?

So what does a water/coolant flow sensor look like? And where would you put it - in a T in the cooling hose after the pump?

This item is available from Moyer Marine. It is an in line pressure switch which activates when there is no pressure in the line. I intend to set mine up with a buzzer that will get my attention.

[hanleyclifford]

The flow sensor switch should be installed somewhere between the raw water pump and the injection point on the hot section. It can be done direct in line or part of a diverter system. I think the preferred point is just before injection.

[ndutton]

So what does a water/coolant flow sensor look like? And where would you put it - in a T in the cooling hose after the pump?

The flow sensor is intended to be installed such that all the water flows through it and can be anywhere in the flow path before or after the block and bypass plumbing. Placing it in a branch Tee will not allow water to flow through resulting in unreliable operation. It is not a pressure switch.

The MMI flow switch is designed to be compatible with the standard Cole-Hersee basic alarm system, also available from MMI.

[hanleyclifford]

Perhaps someone who has actually installed one of these switches could post a picture of the set up?