Overheating engine. Not sure how to proceed.

[lituya1617]

First, get to know your engine. Get the overhaul manual. Your engine appears to be a heat exchanger system with a water cooled exhaust and water muffler. Then diagnose the heating problem systematically. 1. Is enough water coming out of exhaust? Yes- pump and lines OK. Engine may have an internal problem like salting up. No- pump and pump drive and lines problematic, most likely plugged as pump appears functional. Check that the pump drive key is in place. Blow air through all lines to find blockage. After a grounding the most likely cause is clogged inlet and / or raw water filter. 2. Make sure your heat exchanger coolant level is high enough. 3. Make sure you are not sucking air through a break in the inlet hoses - hoses can collapse on the suction side if the inlet is blocked and cause an air leak. It is a simple problem. Don't overthink it. If you are getting water into the pump and the pump is working, you can tell by just loosening the outlet line clamp - water will squirt out. If it isn't working, you will not be pumping water. Don't tear everything apart because it is probably unnecessary. Just find and fix the problem systematically. Start with the easy stuff like looking at the exhaust outflow and measuring it with a bucket. No water flow usually means something is blocked.

[Wotname]

Originally Posted by GILow

Guys, read my followup posts. .......

You are an optimistic laddie .

[klaaskootsra]

Please get a proper mechanic and service the engine together.

- the corrogated hoses should be replaced, as the are prone to collapsing, leaving you effectively with a hole in your boat.
- remaining hoses are not steelwire reinforced. Can be ok, but not advisable
- seacocks are correded, probably inferior material and prone to breaking
- other seacocks don’t function...
- traces of waterleaks everywhere... will kill your engine at some point
- how certain are you that your exhaust line is gastight? Co2 will kill you...
- oja and you have a water blockage somewhere...

Listers are in general well and and trusty, tough this one needs some proper tlc

[davitosan]

Have read question and answers. This is perhaps a bit brutal, but why are you on the water without having made sure everthing on and in your boat is seaworthy and in good condition and you have a reasonable knowledge of how things work. Over 60 years of boating I have helped lots of boats that have not really needed help if the owner had done those things.
Anyway the Lister motor you have is an excellent motor , I had one for many years.It has fresh water cooling using heat exchanger in the exhaust manifold housing. having been on a sand bank you should check every section of the raw water circuit for sand, weed etc. including the tube stack and outflow at the exhaust elbow where the used raw water is injected into the exhaust pipe. Espacialy at this point check the alluminium face as the hole where the water should exit could be corroded and blocked thus restricting the flow through the cooling system.
Your pump should be a Jabsco and parts are easy to get. It looks to be in good condition.

[GILow]

Originally Posted by Wotname

You are an optimistic laddie .

O. M. G.

[Uncle Bob]

Originally Posted by GILow

O. M. G.

Yep, sometimes they just keep on giving.

[skenn_ie]

Are you sure that you are getting the correct impeller ? The gap seems exceedingly tight. Compare it with the MarineHowTo pic. As others have said too, it is obviously suffering from bounce-back, and with extreme deflection/compression of the vanes, that is probably fatal.

[GILow]

Originally Posted by skenn_ie

Are you sure that you are getting the correct impeller ? The gap seems exceedingly tight. Compare it with the MarineHowTo pic. As others have said too, it is obviously suffering from bounce-back, and with extreme deflection/compression of the vanes, that is probably fatal.

It does look a little squeezy, but the flow rate was pretty impressive.

[OneBoatman]

Your picture indicates your engine is fresh water cooled. Your sea water impellor looks normal except for the vane lying in the wrong direction if the engine overheated since you last replaced it may need replacing after you check a few more things. Most probable overheating causes are as follows: #1 restricted sea water intake, solution: a) find and close your close your sea water intake seacock then carefully remove & clean the strainer reassemble the strainer port with proper gasket or O-ring in place and then re-open the seacock. Start the engine and immediately look at the exhaust discharge, it should be discharging seawater at approx three plus gallons per minute near or just above idle and increase to higher flow with RPM. If there is a poor or near zero flow rate from the exhaust discharge you have confirmed a reduced flow on the seawater side. If the seawater impeller is ok then check for carbon buildup in the exhaust riser/mixer. This is among the top three most likely causes of overheating. #2 Low coolant- Find your coolant reservoir and make sure it is at the proper level with no leaks check hoses incl to the hot water tank and check your bilge for evidence of coolant leaks. This is the fluid that actually cools the engine and should be a 50:50 mixture by volume of ethylene glycol antifreeze and distilled water. #3 You may need a new thermostat typical rating would be 185 F. Heat exchanger directions must be counterflow. ie seawater in next to coolant out.

[skenn_ie]

Coolant tank with raw water ? My cooling system has a combined tank (fresh-water) and heat-exchanger, unpressurised (the caps have deliberate pin-holes). Not sure how common that is. I still suspect that the impellor isn't the right one. Good flow (while it lasts) because almost no water passes the deflector plate.

[Bear-O-Ness]

Great informative thread. One thing I have done to check raw water flow from my raw water pump back is to simply remove the hose and blow through it. You should be able to move air from this point through the strainer and out of the through hull even while in the water. I found out my intake was plugged right at the thru hull valve once doing this. Had to take the hose off at the valve and run a rod through it to unblock. Made a mess but worked. Another thought is the mixing elbow. There was a couple of mentions of this but on my Yanmar 3GMF this was a regular maintenance item. About every 1.5 years it would coke up. Had to be removed and soaked in muriatic acid until it finally had to be replaced the last time. Don't know if this is an issue on other boats but it sure was on mine.

[Juggles]

Finally got back to the boat after a terrible trip and even more terrible weather!
Matt came round last week and had a look. The cooling system is working fine at least until the exhaust elbow. Pulled some hoses and saw a really good flow of water. The outlet was under the water line when standing on the back which is annoying. Shifted weight around today to combat that.
We noticed the alarm on the temperature gauge was set to 86 degrees and wouldn't tell you any higher reading after. He suggested setting it higher and taking a video to help diagnose.
Managed to change that to 92 today, but before it got that high a weird clunking noise was coming from the engine so we killed it. Partner thinks it was this random chain that's never been connected to anything. He tried taking it off, but didn't have enough clearance to get it off. Put it back to the side as it was and now the ignition button does nothing. No click, nothing.
At this point I think we're looking at a mechanic or an engineer to help run us through and diagnose wtf is going on. It'd be nice to have someone come through and show us everything over reading books and seeing it on others boat. If anyone knows of a decent mechanic or engineer in Adelaide SA please message me.

Also someone mentioned that its silly to be on the water with such little knowledge. Rest assured were not. Were on other people's boats at the club and the time we took her out was the first. In port river. 200m from the marina. Were not crazy don't worry.

Here's the YouTube video of what we did manage before I heard the noise.
https://youtu.be/Gj8wV4efilQ

[GILow]

Ok, that’s easy.

You’ve got a bad electrical contact, at the battery end in all probability. You can see the temp gauge cutout when the starter draws power, and the click is another clue as the solenoid falls back as the power cuts out. Check the connections. I’d come and help but I’m anchored out tonight.

[Juggles]

Well shoot. I missed that. I'm glad that's all it is. We've got all the kit to replace the batteries and cables in correct colours and gauges but just hadn't gotten to it.
Although someone did mention an AGM is not a great engine battery... haven't looked into it but that's a cheap replacement anyway. Planned on doing it at the same time as the solar, which we've also got all the gear for, not enough time in a day! Will check the connections asap as best I know how anyway.
Were only here for the night anyway, making another sofa bed and then have Australia Day stuff on until Tuesday if you wanted to come around sometime after. Enjoy the peace and quiet out on the water.

[GILow]

Batteries direct just north of you do the best prices and freshest batteries in Adelaide. (No affiliation, just a happy customer).

Yes, AGM is not ideal for your boat. Probably a simple FLA (flooded lead acid) is best for your needs.

AGMs are ok if you have REALLY good charging systems, like quality solar regulators or decent mains powered smart chargers. Otherwise you’ll kill them in no time at all.