SMOKE! SMOKE!

[azazzera]

Took a trip to Northport this past weekend. We left on Sunday early. Turned the raw water valve on but in my haste and excitment to head home with great wind that morning i actualy was turning the valve off. It was already on. Blower on, engine start was fine. Except for my second mistake was not looking for water out the stern. idled for a minute or two then cast off the mooring. Went about 50 or 75 yards when my one sister yelled SMOKE! SMOKE! I imediatly gave her the tiller and climbed down into the cabin. Turned off the engine, pulled the fire extinguisher out and pulled off the panel to the engine. In retrospect maybe not the best thing to open the panel that soon. I thought if this was a fire i just gave it lots of air. As this was all going on I was smelling the familire sweet odor. I was praying please o Lord be an anifreeze leek. I saw no fire no smoke just lots of steam. Confident we were not on fire i quickly turned my attention to the fact we had no power and were drifting in a relitivly narow and busy channel. got the anchor deployed and started to calm myself. the plastic overflow tube was resting on the heat exchanger and melted spraying antifreez over a very hot engine.

So my question is what posable damage could I have done to the engine. My short list is raw water impeller, fresh water impeller, warped heat, burnt oil. Any thing else? O yes a badly bused ego. After cutting the damaged tube back and relocating it so it would reach i had to add strait water the the exchanger and restarted the engine and all seemed fine oil pressure, temp. and water out back. We made it home without a problem. Ran on engine for about an hour or more with no abnormal noise or temp. problems or oil problems. I plan on draining and replacing oil (Rotla 10/40) and same with antifreeze (50/50 mix). My concern is any long term damage that may have been done.

[edwardc]

The A4 is a pretty rugged and forgiving beast with respect to overheating. Given that it didn't seize, you're running without apparent problems, I'd say that you dodged a bullet engine wise. The additional things to watch out for are:

- Damaged exhaust hoses in the wet exhaust section
- Damaged waterlift (if it's plastic or fiberglass. SS will be ok.)

[azazzera]

I consider myself one of the lucky ones who inherited an all copper standpipe exhaust. I'll keep an eye on the joints. Very scary and humbling experience. I'm going to definitely invest in a EWDS as I can afford it. In the mean time I'm going to make a check list I can follow (aviation style). On the up side I guess I found out how I would act in an emergency. Even got to talk to the Coast Guard. Wanted to stay local with a simple announcement if the situation escalated but the marina nore the harbor master were answering at 7:30am. I'll put this one in the very lucky column.

[ndutton]

You can make less costly strides toward an EWDS by installing the prerequisite basic alarm system and flow sensor. You'll need them anyway for the EWDS as they are not included and they'll provide instant monitoring of raw water flow, temp and oil pressure. With this reduced system you would have known something was amiss within seconds of starting the engine.

[azazzera]

Yes. I was thinking about just getting that set up for now.

[azazzera]

I do have a question about how all of these sensors get wired. I'm assuming the get there power from the ignition circuit. What's the starting point? Dose it matter?

[ndutton]

You are correct that the power source is typically the ignition circuit. 12V+ goes to the buzzer and the - leg comes through the sensors to the other side of the buzzer. The system adds no load to the ignition because the circuit is open until a sensor trips.

[roadnsky]

+1 for having the flow sensor alarm.
Because of a generous B-Day gift, I have the full monty EWDS.

I went out today and while starting up the A4 got a little bit distracted by a "dock-walker" who wanted to talk...
Forgot to open the thru hull. Within seconds the alarm went off and I immediately knew what was up because of the idiot lite on the control panel.

Now, I probably would have caught this before a melt down BUT with the discussion going on... who knows.

[toddster]

Originally Posted by azazzera

I do have a question about how all of these sensors get wired. I'm assuming the get there power from the ignition circuit. What's the starting point? Dose it matter?

I think the oil-pressure/temperature/alarm kit is the starting point. You need that before you can add the water flow sensor.

(Hint: be very careful tightening the tube adapters into the nylon flow sensor. Very easy to crack. Don't ask me how I know. :roll eyes: )

[ndutton]

The nylon fittings don't need to be wrench tight to make a good seal with teflon tape.

[azazzera]

I have purchased the flow, oil and temp, switches. Waiting for delivery on all the components. The mention of teflon tape bring up a question though. Tape or paste. I'm a paste fan. What's the consensus on paste vs tape. I fall on the side that tape can tear and become a thrombus in the system. Or is it all preference?
And just again about the wiring of all this. I will wun a (+) positive wire from somewhere off of the ignition circuit. Say the starter solenoid or pick it up from one of the gauges to the one side of the buzzer. Then the other side of the buzzer will get daisy chained to the negative side to the block or neg bus. I see that the flow sensor has two wires out of it. How dose that get handled?

[azazzera]

Just working this through in my head the buzzer needs to get positive and negative because it's not grounded through the block and has no other way to close the circuit. And the other switches are grounded trough the block, excluding the water flow switch, so when closed will close the circuit through the negative side. That leaves the flow sensor that if I have this stuff clear in my mind �� Would need a positive and negative connection to close the circuit due to it not being grounded by the block. Do I have the basics right? Please be right. It would give my ego a nice boost and make me feel like I'm finally understanding a little about this electrical voodoo.

[azazzera]

Ok. Because what else is my insomnia at 12:56 EST good for but to think more about this. If I were to simple continue the daisy chain with the flow sensor and hook the other side or second wire to the negative side say back to the block or to a neg bus. The circuit closes by the no flow and that is what closes the circuit so it would not need to have positive input????

[JOHN COOKSON]

Originally Posted by azazzera

Ok. Because what else is my insomnia at 12:56 EST good for but to think more about this.

Is the insomnia leading to thinking or is thinking leading to insomnia?
I'll bet if you sleep on it you will know the answer to the question you are thinking about in the morning.
The sailing remedy is a couple of Marazine (spelling?) and a double shot of brandy. Good Night.

TRUE GRIT

[azazzera]

roadnsky: examining your picture I see that your ignition switch is on and the oil light is on. You oil and temp gauges are flat. Although it's a vacuum gauge are you using it as a tach? That's flat as well. So I'm making the assumption that the engine is not started yet. If that's true then shouldn't the flow and fuel light be on too?

[ndutton]

The alarm sensors are grounded by their mounting so when tripped they complete the ground path to the buzzer with the single exception of the flow sensor. It has a plastic body so it has an additional wire (black) to provide its ground path. You are correct that in the basic system the sensors are daisy chained together and connected to the buzzer. Any one of them trips and the buzzer then gets its ground and operates. When installing the EWDS later, the daisy chain wire is discarded and the sensors are connected separately.

Don't overthink this too much. One great advantage to purchasing from MMI is detailed installation instructions.

About Jerry's panel display, it shows zero oil pressure (hopefully engine off), engine temp and coil input voltage within acceptable range. Knowing he has an electric fuel pump, if his engine had been running it's normal for the fuel line to hold pressure for a while following shut down and it's possible the flow sensor had not yet returned to it's default position. His report reinforces the reason the EWDS exists: the sooner you know about a problem and the sooner you can find it, the better.

[azazzera]

Yes compleatly agree on the efficacy of the ewds. It will definitely be a purchase in the future.

I'm usually not that observant with pictures. It just struck an interest in me. Maybe it's to much NCIS episodes. Not to beat this horse but the temp gauge is flat so I would assume that the engine was not hot because even with the ignition on and the engine off but the engine warm the gauge would show life. Sooo. I'll accept your residual pressure from the fuel switch not tripping the light but not sure on why the flow light is not on.

[ndutton]

The flow sensor has a sliding magnetic transducer inside that returns to default with a light tension stainless spring. Depending on its orientation (horizontal mounting is recommended) minor engine vibration actually aids its operation. I think Jerry's testament to its operation really tells the tale.

[azazzera]

Just a quick question about placement of the flow switch. I plan on placing it after the strainer but where. Dose it matter before or after the pump? I have a fwc system. I'm obviously putting it on the raw water loop. Do you think that a second switch on a separate alarm in the fresh loop make any sense?

[roadnsky]

Originally Posted by azazzera

So I'm making the assumption that the engine is not started yet. If that's true then shouldn't the flow and fuel light be on too?

Sorry, I was sleeping

I guess the pic is a little mis-leading. It is not from yesterday's "event".
It's fairly old and was just to show the panel with EWDS.
The engine wasn't running and at that point I don't think I had the flow sensor hooked up yet.

Although it's a vacuum gauge are you using it as a tach?

I have a Tach Gauge mounted separate from the panel.

[azazzera]

Thank you jerry. What dose the vacuum gauge do for you and we're is it hooked up.

[roadnsky]

Originally Posted by azazzera

What dose the vacuum gauge do for you and we're is it hooked up.

It gives me a quick, "at-a-glance" view of the carb/fuel performance.
Mine is attached to a port in the manifold.

[ndutton]

My flow sensor is located in the pump's discharge side before the heat exchanger. I preferred having the pump push rather than suck through it.

[sastanley]

Neil, I like that idea for the sensor location. Is there any room for expansion to add a 2nd flow sensor (or can you have two sensors on the same idiot light)? I think I am planning to install a flow sensor on both the raw & antifreeze side of the HX.

[ndutton]

My caution to you Shawn is our normal FWC coolant temp is very close to the sensor's maximum specification, that is, no margin of safety. Also, for those such as you and me with electric coolant pumps the last thing you want is to add a restriction, even a small one @7%, to the coolant circuit. To answer your question directly though, you can add as many flow sensors as you want wired in parallel