I think the fresh water pump was starved of liquid to pump, likely caused by an air lock. That the heat exchanger vent didn't exhaust water or air is another indication of this. Later, the hose pressure from the power flush probably cleared the air lock. Flushing the system should also have improved heat transfer into the coolant, assuming that you flushed with some kind of acid to remove any scale and also any coolant additive precipitate (from switching coolant types). The video doesn't show if you ran the engine afterward, so your problem might already be solved.
I was and ASE auto tech from '93 to '01 and saw many damaged engines from tap water mixed with antifreeze. Glycol base coolants when mixed with tap water, especially from a mineral rich water source like a well or spring, will cause the deposits you're finding in the coolant. All coolant manufactures, auto manufacturers, and marine engine manufacturers recommend distilled water only when using glycol based coolants. The deposits are more of a problem in a vehicle radiator than a boat heat exchanger because the passages are smaller. Antifreeze isn't a good chemical for heat transfer and a system with more than 50% antifreeze can overheat in warm weather. I could post links but messages usually get flagged or blocked with them.. Another thing that I know happens with gasoline marine engines is that cooling water on the fresh side doesn't circulate through any parts outside of the block until the thermostat opens. Not sure on diesels but I think they would be similar. A diesel needs a lot of heat for combustion. If you have the old water pump, look at them side by side and count the fins/vanes on the impeller. I've seen this with both auto and marine engines before. Make sure the fins/vanes are the same size and have the same angle. The reason for no sealants on the water pump and plate is the gaskets help set a tolerance between the water pump fins/vanes and the plate. If there is excess clearance, the impeller will not move coolant as efficiently or at all. Then there is the problem with sealants blocking water flow or breaking off and blocking cooling passages. I really hope you get this sorted out with a definitive answer on the problem.
Great episode. I am currently watching all the related episodes. Your detailed analysis and explanations while troubleshooting is very helpful. I’m taking detailed notes. I’ll be pulling my cooling system apart on our Universal 25 this winter. While our engines are different the basics and principles apply to both. Very grateful. Cheers Kevin H
the raw water side is ok, so inlet, gearbox cooler, pump, heat exchanger tubes and elbow are all ok. the fw is not circulating that is certain so either the pump is 1) not getting water from inlet 2) not pumping water 3) can't pump water to outlet #1 is pretty much ruled out as that is a direct connection (through the middle of the pump opening) to the block #2 impeller loose on shaft (doesn't look like it from video) or air lock (imho most likely) #3 blockage on outlet You can test #3 by sticking a hose in the pump outlet (the circular bit on the engine) and checking water goes somewhere A water pump on an engine like this is not a pump in the normal sense - it really just assists the thermo-siphon effect i.e. hot water rises & cool sinks & when arranged properly the water will circulate by itself - the pump just speed this up. An air-lock will completely stop this circulation, leaving the pump to just turn in the hot water. Maybe try eliminating that long hose 'loop' or better make it *just* the highest point and then use it to fill the engine *very* slowly until engine full, then when water (without bubbles is coming out of the heat exchanger vent close that and then bring both ends of the hose lower until water comes out of both and connect. I had one of these in a Land Rover and the heater circuit used to cause a similar problem if not filled correctly. These are very basic, solid engines that were installed in tractors and similar they are not fussy about grades of water or anti freeze
As to the white jelly stuff, this might be due to using two different antifreeze liquids. In the case of Volvo engines you have to use one type of antifreeze only. If you ever mix it with another one, still from Volvo, it gellyfies and its over. Just a thought. Regards from Switzerland, Silvano
I've got the same I just wanted to say I've got the same motor as you Perkins 4108 I bought it rebuilt and had my mechanic install it and it kept overheating and we tried everything and it still kept overheating until my pop told me it's the propeller take it off and have it repitched and that's what I did and it cured the problem it was the prop the whole time and not the motor just thought I'd let you know that it runs about a hundred and eighty degrees at about 2,000 RPMs and she's been running great ever since I got the prop free pitched so maybe that's something to look into your friend trucker Doug on Savannah breeze
I had the same problem from a coolant missmatch for yearssss. I had to flush it out several times and finally overcame the problem. I used vinegar antifreeze flush, even tapped in a pressure wash like you did. Mine was a lowline too.. It was nuts I have a turnbuckle on my alternator too!!!
That’s good and terrible to hear. I wish there was more info on that issue online. We were totally flummoxed by it. We spent about $20k on the new engine, but having an engine that I never question whether it will start or not has been priceless.
Check your exhaust elbow, (the water side) if its cast iron and all bubbled up inside, seawater can't pass thru it quick enough to carry away the heat generated by the engine,
Would your sealant where you said it should be a dry fit have any affect on clearance at pump impeller? I'm an airplane mechanic so we don't deal with this water stuff too much. :) Good luck!
Did you run it without the thermostat while flushing? I have the exact same motor and this is a mystery especially since I had mine stripped down recently to replace the injector pump. Completely drained the coolant (I removed the heat exchanger) and refilled without experiencing any air pockets or difficulties. Anyway while you’re in there check the high pressure injector lines for corrosion and everything else in the area because as you already know you have to take everything off to do anything on that side of the block. Trans Atlantic has just about everything in stock (ask me how I know lol)…
Thanks Michael, I did pull the t-stat and reinstall the header tank before running it and overheating again. I'm pulling the oil cooler this weekend. Funny about TAD, but when I called them I was told they didn't have any of the gaskets I need for this teardown. Maybe you know something I don't?
fresh water flow, on a 4-108 fresh water pump, there are TWO gaskets between the pump and the engine block, with a thin metal plate between the gaskets. THESE GASKETS ARE NOT IDENTICAL.
The tach on my Perkins reads zero if the battery is fully charged, and solar is incoming. The Balmar regulator reads that and sends out a zero RPM signal for some reason. Try to disable any other charging systems (solar or 120v) and see if the tach recovers. I have to disable my solar charger when we motor long distances which solved it for me
I was also going to mention that the coolant water won't start to circulate until the engine is up to the thermostat temp (170ish gone or take). Test the water pump by running the engine with no thermostat in place.
I was thinking that too, but there looks to be good flow on the raw water side. There's no flow in the fresh water side. I wonder if you can use barnacle buster on the fresh water side? If the water pump is spinning there could be obstruction in that path.
I think the fresh water pump was starved of liquid to pump, likely caused by an air lock. That the heat exchanger vent didn't exhaust water or air is another indication of this.
Later, the hose pressure from the power flush probably cleared the air lock. Flushing the system should also have improved heat transfer into the coolant, assuming that you flushed with some kind of acid to remove any scale and also any coolant additive precipitate (from switching coolant types).
The video doesn't show if you ran the engine afterward, so your problem might already be solved.
I was and ASE auto tech from '93 to '01 and saw many damaged engines from tap water mixed with antifreeze. Glycol base coolants when mixed with tap water, especially from a mineral rich water source like a well or spring, will cause the deposits you're finding in the coolant. All coolant manufactures, auto manufacturers, and marine engine manufacturers recommend distilled water only when using glycol based coolants. The deposits are more of a problem in a vehicle radiator than a boat heat exchanger because the passages are smaller. Antifreeze isn't a good chemical for heat transfer and a system with more than 50% antifreeze can overheat in warm weather. I could post links but messages usually get flagged or blocked with them.. Another thing that I know happens with gasoline marine engines is that cooling water on the fresh side doesn't circulate through any parts outside of the block until the thermostat opens. Not sure on diesels but I think they would be similar. A diesel needs a lot of heat for combustion. If you have the old water pump, look at them side by side and count the fins/vanes on the impeller. I've seen this with both auto and marine engines before. Make sure the fins/vanes are the same size and have the same angle. The reason for no sealants on the water pump and plate is the gaskets help set a tolerance between the water pump fins/vanes and the plate. If there is excess clearance, the impeller will not move coolant as efficiently or at all. Then there is the problem with sealants blocking water flow or breaking off and blocking cooling passages. I really hope you get this sorted out with a definitive answer on the problem.
Great new opening Jeni
Thank you!
Great episode. I am currently watching all the related episodes. Your detailed analysis and explanations while troubleshooting is very helpful. I’m taking detailed notes. I’ll be pulling my cooling system apart on our Universal 25 this winter. While our engines are different the basics and principles apply to both. Very grateful. Cheers Kevin H
the raw water side is ok, so inlet, gearbox cooler, pump, heat exchanger tubes and elbow are all ok.
the fw is not circulating that is certain so either the pump is 1) not getting water from inlet 2) not pumping water 3) can't pump water to outlet
#1 is pretty much ruled out as that is a direct connection (through the middle of the pump opening) to the block
#2 impeller loose on shaft (doesn't look like it from video) or air lock (imho most likely)
#3 blockage on outlet
You can test #3 by sticking a hose in the pump outlet (the circular bit on the engine) and checking water goes somewhere
A water pump on an engine like this is not a pump in the normal sense - it really just assists the thermo-siphon effect i.e. hot water rises & cool sinks & when arranged properly the water will circulate by itself - the pump just speed this up.
An air-lock will completely stop this circulation, leaving the pump to just turn in the hot water.
Maybe try eliminating that long hose 'loop' or better make it *just* the highest point and then use it to fill the engine *very* slowly until engine full, then when water (without bubbles is coming out of the heat exchanger vent close that and then bring both ends of the hose lower until water comes out of both and connect.
I had one of these in a Land Rover and the heater circuit used to cause a similar problem if not filled correctly.
These are very basic, solid engines that were installed in tractors and similar they are not fussy about grades of water or anti freeze
As to the white jelly stuff, this might be due to using two different antifreeze liquids. In the case of Volvo engines you have to use one type of antifreeze only. If you ever mix it with another one, still from Volvo, it gellyfies and its over. Just a thought. Regards from Switzerland, Silvano
Interesting! Are you absolutely sure the fresh water pump impeller doesn't freewheel when under load? This happens on some cars too.
in this video i finally see where the thermostat is on my engine. Thanks!
Glad I could help!
I've got the same I just wanted to say I've got the same motor as you Perkins 4108 I bought it rebuilt and had my mechanic install it and it kept overheating and we tried everything and it still kept overheating until my pop told me it's the propeller take it off and have it repitched and that's what I did and it cured the problem it was the prop the whole time and not the motor just thought I'd let you know that it runs about a hundred and eighty degrees at about 2,000 RPMs and she's been running great ever since I got the prop free pitched so maybe that's something to look into your friend trucker Doug on Savannah breeze
What pitch did you go with? What size prop, what size and displacement boat are you running? My 4.108 is running 195 degrees at 1700 rmp
A photo of Ramble On just made the New York Times in an article about boating in the Delta.
Hi Warren - We saw that! We saw the author taking photos a couple of weeks ago but had no idea why. Thanks for letting us know!
I had an issue with my 4.108 but it wound up being an issue with the exchanger which was scaled up.
I had the same problem from a coolant missmatch for yearssss. I had to flush it out several times and finally overcame the problem. I used vinegar antifreeze flush, even tapped in a pressure wash like you did. Mine was a lowline too.. It was nuts
I have a turnbuckle on my alternator too!!!
That’s good and terrible to hear. I wish there was more info on that issue online. We were totally flummoxed by it. We spent about $20k on the new engine, but having an engine that I never question whether it will start or not has been priceless.
Check your exhaust elbow, (the water side) if its cast iron and all bubbled up inside, seawater can't pass thru it quick enough to carry away the heat generated by the engine,
The saga continues, can you say ‘mission creep’? Good luck and thank you for sharing.
I’m thinking you probably have an air pocket in the fresh water cooling system, which is keeping the coolant from circulating
Would your sealant where you said it should be a dry fit have any affect on clearance at pump impeller? I'm an airplane mechanic so we don't deal with this water stuff too much. :) Good luck!
Not sure, but I think it may be something solid blocking the water passages in the motor. I'll be working on this weekend.
Did you run it without the thermostat while flushing? I have the exact same motor and this is a mystery especially since I had mine stripped down recently to replace the injector pump. Completely drained the coolant (I removed the heat exchanger) and refilled without experiencing any air pockets or difficulties. Anyway while you’re in there check the high pressure injector lines for corrosion and everything else in the area because as you already know you have to take everything off to do anything on that side of the block. Trans Atlantic has just about everything in stock (ask me how I know lol)…
Thanks Michael, I did pull the t-stat and reinstall the header tank before running it and overheating again. I'm pulling the oil cooler this weekend. Funny about TAD, but when I called them I was told they didn't have any of the gaskets I need for this teardown. Maybe you know something I don't?
What temperature are you running when it overheats and what is your RPM when that happens?
We had a high temp alarm that turns on at 200f, and she boiled over and blew coolant all over the engine compartment.
fresh water flow, on a 4-108 fresh water pump, there are TWO gaskets between the pump and the engine block, with a thin metal plate between the gaskets. THESE GASKETS ARE NOT IDENTICAL.
Thanks Art, I learned that when I installed the Balmar serpentine alternator and water pump kit.
The tach on my Perkins reads zero if the battery is fully charged, and solar is incoming. The Balmar regulator reads that and sends out a zero RPM signal for some reason. Try to disable any other charging systems (solar or 120v) and see if the tach recovers.
I have to disable my solar charger when we motor long distances which solved it for me
I was also going to mention that the coolant water won't start to circulate until the engine is up to the thermostat temp (170ish gone or take). Test the water pump by running the engine with no thermostat in place.
Thanks, I check that out when I start putting it back together.
Flush with barnacle buster
I was thinking that too, but there looks to be good flow on the raw water side. There's no flow in the fresh water side. I wonder if you can use barnacle buster on the fresh water side? If the water pump is spinning there could be obstruction in that path.
Interesting! Are you absolutely sure the fresh water pump impeller doesn't freewheel when under load? This happens on some cars too.
Was my idea too.