Engine Shut Down

[Steve Pope 243]

There was a time when a thermostat crapped out it stayed open, ever since the wax stats took over when they crap out they crap out closed.

[sealegs 0]

There is nothing wrong with trying to understand your engine, or any other system in your boat. Quite the opposite.

However I agree that you should only go against professional advice after careful consideration.

There is a lot of crap on the internet, tread carefully. Not all "professionals" are trustworthy, or even competent either.

Checking a thermostat is a pretty simple job, and, in this case one not closing properly is easy to see. Any doubt, easy and cheap to replace on most engines. Its not a bad place to start. Don't forget to use inhibitor/antifreeze when you refill the cooling system, as per the owners manual.

 

 

Thanks again island time for providing that grumpy old fart (pwederell) with an appropriate answer in my defence. You are quite correct. I do want to understand the motor and its workings since motor mechanics is not my field.I dont have a problem with replacing faulty parts but I do like to "prove" a fault and be assured thereby that I have found the actual problem and I learnt something new along the way.(My field is telecommunication network building & fault finding and I spent a lot of time seeking the fault's location by doing various tests on the network)

 

I agree with your comment re There is a lot of crap on the internet but have fortunately experienced many knowledgeable sailors like yourself & others on this site who are very friendly (with the exception of pwederell) & helpful with reliable problem solving suggestions hence my questions from time to time. I do also speak to other professionals when the problem is beyond my ability to rectify DIY.

 

(now lets wait for pwederell's usual abusive response..if any )

[idlerboat 116]

I know of a few boat where the raw water inlet has a "T" to the (usualy) sink freshwater inlet. On Marina or whatever shutdown, the Y valve is changed so that for a few seconds tank water (fresh) runs through the engine.

I have no idea if this makes a big differance.

Another boat I know of, a metal H28 (yes there is such a thing) has a Y valve on the sink outlet. This allows him to fill the sink with fresh water and it then flows through and flushes the engine. Again I have no idea how much differance or longevity to the engine it makes.

 

cheers

[Island Time 1,239]

The fact is, it does bugger all. What it does do, is add another risk to the engines safe operation. If the valve is accidentally left in the wrong position, its possible either no coolant or air will be introduced to the system with bad consequences. Raw water cooled engines often last over 20 years without issues.unless aluminum. My advice is don't overly complicate things.

[Guest]

(now lets wait for pwederell's usual abusive response..if any )

Make sure you ignore manufacturer's recommendations at all costs and run engine as cold as possible. This is the best thing for sensitive people.

[sealegs 0]

(now lets wait for pwederell's usual abusive response..if any )

Make sure you ignore manufacturer's recommendations at all costs and run engine as cold as possible. This is the best thing for sensitive people.

 

you're a funny but "grumpy old fart pwederell"

[sealegs 0]

The fact is, it does bugger all. What it does do, is add another risk to the engines safe operation. If the valve is accidentally left in the wrong position, its possible either no coolant or air will be introduced to the system with bad consequences. Raw water cooled engines often last over 20 years without issues.unless aluminum. My advice is don't overly complicate things.

 

agreed island time there is risk if you forget to place Y valve in correct position. I have a check list for start up & shut down I follow religiously and checking that Y valve is No1 on the list & I dont mind taking my time to be sure everything is in order before starting up or shutting down /leaving the boat on its mooring.

 

I do disagree with you on flushing with fresh water though.Surely flushing out the salt water is a good thing and can only benefit the cooling system's operation?

 

Some might prefer the traditional method of disconnecting the raw water pipe annually to flush the system. I just fitted the Y valve to make that job less of a time consuming exercise and allows me to do it more often than annually.

 

By the way, I just downloaded the workshop manual of the motor and yep..there it was as you said...

Refrigerant temperature too low

If the refrigerant temperature is too low this may be because

of:

- Defective thermostat.

- Defective temperature sensor or instrument.

 

Must say the process to remove the thermostat is a bummer due to lack of space but still possible to diy I suppose.

 

1. Remove both battery leads. Drain off the water in the fresh water system. 2. Drain off the water in the sea water system.

3 Remove the alternator , Release the exhaust pipe and remove the heat exchanger housing complete. Remove the spring and lift out the thermostat from the housing.

 

Followed by:

Checking the thermostat

1. Check that the thermostat closes completely.

2. Heat up water in a vessel to 68°C 1 154.4°F

3. Submerge the thermostat in the water. Check after at least 3-5 minutes that the thermostat is still closed.

4. Raise the temperature to boiling point (100°C /212°F). Check after 3-5 minutes that the thermostat has opened at least 6 mm

Replace the thermostat if these specifications are not met. NOTE! If the thermostat does not close completely the engine will run at too low a temperature

 

Since its now presumed proven AND its that much effort to check the thermostat I shall just replace it with new one once and for all when I open up the system.

So you see pwederell I would not have learnt all of this if somebody on the internet did not point it out to me in detail which prompted me to get the workshop manual as well. The operator manual I have does not have as much detail hence my initial query.

I'm happy . Ive got more knowledge to absorb thanks to this forum's helpful experts ( ...and a grumpy old fart ! )

[Island Time 1,239]

The saltwater side of the cooling system is designed for salt water. Its materials are quite resistant. Normally there is an anode or 2 as well. Cast iron is very resistant to salt water. Heat exchangers are the normal weak point. The manuals would tell you to do this if it was required. But hey, your boat!

[idlerboat 116]

Make sure you ignore manufacturer's recommendations at all costs and run engine as cold as possible.

Now no matter what the fluff n bubble, spit n spite, Fart n trouble. of the post that have been ..

ALWAYS run your engine AT MANUFACTURERS TEMP SPECIFACATIONS>

The engine tolerances are designed around heat expansion. They give the most power and least oil loss.

They are the most fuel efficient.

[wheels 543]

Interestingly the now famous "60% of engine wear occurs at start up" has become an urban legend. While it is true, it is actually not as what many understand. The actual truth is reffering to petrol engines and the wear was the fact that when the engine is cold, it would condense water and water and Sulphur created Sulphuric acid and that is what actually caused the most wear.

The most important point to always remember with a Diesel engine is that you can Kill them with Kindness. Never warm the engine by idling it. ALWAYS put it in gear and warm it under load with a little RPM. If on a mooring, put it in reverse and pull on the line. Unless under load, you may never get an engine up to full temp anyway.

Raw water cooled engines always run a little colder than fresh water closed system cooling. Make sure you run a good corrosion inhibitor in a closed system. Cheap is usually nothing more than glycol. Expensive tends to have all the corrosion inhibitors added.

[Guest]

Does the manufacturer recommend that you compromise the integrity of the cooling system by adding a Y valve? Or is this your idea from your years of experience repairing telephones?

[sealegs 0]

Does the manufacturer recommend that you compromise the integrity of the cooling system by adding a Y valve? Or is this your idea from your years of experience repairing telephones?

 

The manufacturer recommends that the seawater system be flushed at the start of winter or out of season/at lay up. ( Island time for your info )

The manufacturer also recommends this flushing be done on dry land due to risk of removing inlet hose from seacock for sucking up the fresh water from a bucket.

 

The manufacturer states that after flushing the system with fresh water for a few minutes, repeat the flush with 50/50 glycol mixture and then to stop the engine before all the glycol is sucked up ..then leave that mixture inside the engine for the duration of the lay up period.

 

Yep...Thats all understood.

Problem ... All that procedures assumes that the boat remains on dry land for the duration of the lay up period and we know THAT is not a cheap exercise for most large vessel owners.

This boat has to stay on the mooring for the duration so... How to flush the system WITHOUT risk to the vessel when tampering with the seacock hose (as manufacturer stipulates) while still in the water?

 

Solution !

 

Fit a Y valve..... and 1) the sinking risk is minimised, 2) engine can be flushed as stipulated BUT while in the water and still on the mooring at minimum/zero cost.

 

Important written note of caution to owner : ALWAYS CHECK Y VALVE BEFORE STARTUP!

[sealegs 0]

Interestingly the now famous "60% of engine wear occurs at start up" has become an urban legend. While it is true, it is actually not as what many understand. The actual truth is reffering to petrol engines and the wear was the fact that when the engine is cold, it would condense water and water and Sulphur created Sulphuric acid and that is what actually caused the most wear.

The most important point to always remember with a Diesel engine is that you can Kill them with Kindness. Never warm the engine by idling it. ALWAYS put it in gear and warm it under load with a little RPM. If on a mooring, put it in reverse and pull on the line. Unless under load, you may never get an engine up to full temp anyway.

Raw water cooled engines always run a little colder than fresh water closed system cooling. Make sure you run a good corrosion inhibitor in a closed system. Cheap is usually nothing more than glycol. Expensive tends to have all the corrosion inhibitors added.

 

Unless under load, you may never get an engine up to full temp anyway.

 

Thanks for that detailed info Wheels. I did wonder initially after reading some of the comments as to the possible cause of low coolant temp whether it was perhaps due to the lack of a load on the motor as opposed to a faulty thermostat. I'm going to take it for a sail in a few days and will motor a bit to check if it comes up to operating temperature. Very pleased with the helpful comments of all.

[Island Time 1,239]

Sea legs, the "start of winter or before layup" is for winterising, for northern hemisphere (usually). They also normally expect the boat to be hauled for that period, and, after flushing, recommend either complete system draining, or changing the antifreeze. This is all to prevent the water in the engine freezing and therefore expanding, which can split important parts. Block, head, heat exchangers etc. Not sure exactly what your manual says, but it will be along those lines. Its not a problem you have to deal with in this part of the world at sea level.

 

Wheels, I've never seen a leisure boat engine that would not reach temp at idle? I guess theoretically it could be the case if you are heating a hot water cylinder etc, but I thought that the water passing through a jiggle pin alone would be insufficient for cooling, even at idle. Interesting. I agree, loading a diesel is good!

 

Sea legs, if you are going to measure the engine temp with a laser, do it at the thermostat housing. Temp varies quite a bit over the engine surface and accessories.

[sealegs 0]

The saltwater side of the cooling system is designed for salt water. Its materials are quite resistant. Normally there is an anode or 2 as well. Cast iron is very resistant to salt water. Heat exchangers are the normal weak point. The manuals would tell you to do this if it was required. But hey, your boat!

 

Its materials are quite resistant./Cast iron is very resistant to salt water.

 

Thanks Island time. That is very reassuring to know. Those tiny tubes in the heat exchanger getting blocked is what bothered me most and I was not looking forward to removing the entire heat exchanger if its required. As a newbie on boats I am very cautious when it comes to the engine side of things. I can follow a workshop guide no problem BUT I dont have the confidence of experience like you chaps have (note! pwederell ) So I really appreciate the helpful comments ( with the exception of those cheeky comments coming from grumpy old farts ).

 

If I need to replace the thermostat I shall take the heat exchanger apart as well to check & clean if required. (To get to the thermostat the heat exchanger must be removed)

I do enjoy this new learning curve and the challenges it brings from time to time.

[sealegs 0]

Sea legs, the "start of winter or before layup" is for winterising, for northern hemisphere (usually). They also normally expect the boat to be hauled for that period, and, after flushing, recommend either complete system draining, or changing the antifreeze. This is all to prevent the water in the engine freezing and therefore expanding, which can split important parts. Block, head, heat exchangers etc. Not sure exactly what your manual says, but it will be along those lines. Its not a problem you have to deal with in this part of the world at sea level.

 

Sea legs, if you are going to measure the engine temp with a laser, do it at the thermostat housing. Temp varies quite a bit over the engine surface and accessories.

 

My understanding of the manuals Sea water system: Flush section is that its not dependant on the hemisphere you're in but rather part of the routine maintenance.

 

Under the next section for Seawater system;Draining the manual refers to the possibility of freezing in the engine compartment which will require removal of all seawater from seacock thru impeller - heat exchanger - exhaust and all additional equipment connected to the seawater system.

 

This is obviously not a problem in our hemisphere.... however a mate of mine bought a 33ft boat a year ago that was on a mooring for possibly years without use ( owner overseas) . He removed all the water in the bilge which was up to the floor boards and used the boat.

What he did not realise was that part of the engine salt water & exhaust system was rusted and leaking which flooded the boat and engine & completely ruined the yanmar engine.

$17000 later with new replacement engine acquired..& lesson learnt!

[Island Time 1,239]

As part of your annual maintenance, heat exchangers should be removed, visually inspected, cleaned and have their annodes replaced. Remember you can have multiple heat exchangers. I have 3. Main engine, oil, and freezer. For mine, a 22cal rifle cleaning brush works a treat.

The sea life that accumulates in them is amazing, even after the incoming water is strained. Also sand and foreign bodies. This is why they need to be removed, opened and inspected. If you find a problem, often your local automotive radiator shop can repair or recore them...

 

Otherwise just clean and refit. Takes me 1/2 a day to do all three.

 

Many owners don't do this, but it will lead to overheating in due course if you don't. Or worse.

[Guest]

Buy a yacht, it seems a motherload less drama.

[sealegs 0]

As part of your annual maintenance, heat exchangers should be removed, visually inspected, cleaned and have their annodes replaced. Remember you can have multiple heat exchangers. I have 3. Main engine, oil, and freezer. For mine, a 22cal rifle cleaning brush works a treat.

The sea life that accumulates in them is amazing, even after the incoming water is strained. Also sand and foreign bodies. This is why they need to be removed, opened and inspected. If you find a problem, often your local automotive radiator shop can repair or recore them...

 

Many owners don't do this, but it will lead to overheating in due course if you don't. Or worse.

 

Ok so what engine & boat do you have? Your profile pic indicates you've been cruising. where did you go? any technical problems along the way with boat?

[sealegs 0]

Buy a yacht, it seems a motherload less drama.

 

hmmm. Knot Me an old man told me AFTER I bought my yacht that its just a hole you throw money into all the time.

I responded with "dont tell my wife please "