E38 w 5432 universal A. Overheating

[FLokiDk]

I ran into overheating issues lately after changing oil and filters.
It started after pushing the engine a bit more than normal for 20 min, but never had any issues before that
So I started going through stuff.
.
- seacock check from outside, removed blocking barnicle... Didn't change anything
- changed coolant no change to problem.
-cleaned raw water strainer, not much there, but uncovered small cracks in plastic around bolts. Made a rubber seal.
When running nothing is leaking but a few drops comes after killing engine(Im getting new filter but flow og of water seemed just fine.
- checked all hoses in fresh and raw water circuits(up to elbow with saltwater)
Took heat exchanger apart, cleaned it good, installed new zinc anode.
Water flow through exhaust improved considerable but engine still ran above operating after half an hour in idle with very little throttle.
My main thoughts is that it could be the elbow clogging, but I have some other weird stuff, we took out around 8,2 liter of oil, byt was only able to add 7,4 liters before dipstick showed 70% of the area if measure) and with the coolant it was a bit the same coolant was guestimated to 0,75 liters less added. Neither oil or coolant level changed much after a few short runs and coolant top off.


Even though my thoughts are on the elbow, I'm still wondering if the are airpockets in oil/coolants, and how to check/handle that
I'm new to engines but not utterly hopeless. I'm going to ask a mechanic to help with the elbow today, but I might end up doing it myself if looking into waiting many days for mechanic to have time
Any input is appreciated, also on what not to use of coolant/what to use.

Hope to hear from ya soon

Keep up the good spirit.
Torben - Martinique atm..
-

 

[Pete the Cat]

Seems like you are doing exactly the right thing. Running down most problems is seldom a one hit deal. But you learn a lot about your boat and can do a lot of preventive stuff along the way. Good luck. I would say the elbow is a good next target. Engines run at 80% of RPM produce less carbon build up and heat--so you might look at at your prop at some time in the future for pitch and barnacles.

 

[FLokiDk]

Update, elbow was very clean, this is a bit strange. I'm going to check the coolant pump, freshwater pump I think it's called, maybe the coolant is even circulated properly
I thought I had a spare gasket for the connection between elbow and engine/exhaust. But it was the wrong one. Is there a possible temporary workaround this?

 

[Loren Beach]

Sorry for a dumb question, but have you recently replaced the thermostat?

 

[G Kiba]

Torben, It's a long shot but I had temperatures rising caused by a 2 Micon primary fuel filter installed where a 30 micron should have been. Temperature was just a bit above normal (5-10 degrees) after running at a higher throttle for 20 minutes or more. After replacing the filter with a 10 micron, no rise at all. I also had better throttle response and a higher top end speed. The engine was so starved for fuel it could not reach the spec 3200 rpm.

 

[c.gustafson]

Maybe you've got some air trapped in one of the coolant lines and the coolant is not circulating as normal? You might try bleeding the coolant line.

 

[FLokiDk]

Torben, It's a long shot but I had temperatures rising caused by a 2 Micon primary fuel filter installed where a 30 micron should have been. Temperature was just a bit above normal (5-10 degrees) after running at a higher throttle for 20 minutes or more. After replacing the filter with a 10 micron, no rise at all. I also had better throttle response and a higher top end speed. The engine was so starved for fuel it could not reach the spec 3200 rpm.

We out in 10 micron, but thanks for the info, would never have thought of that

 

[FLokiDk]

Maybe you've got some air trapped in one of the coolant lines and the coolant is not circulating as normal? You might try bleeding the coolant line.

Bleeding the lines would be loosening in one end and keeping rest of hose below for the bubble to come out there?

 

[Christian Williams]

Is your water heater plumbed to the thermostat bypass, such that coolant hoses to the heater go over the engine? If so, that's the highest point. I installed a bleed valve there. If your heater connects to the heat exchanger, and no part of the system is above the coolant cap, then the system bleeds automatically with the coolant tank cap off. I doubt that's it, though.

I doubt it's the fuel filter, I have run 2 micron primaries for years.

The heat exchanger was "boiled out" with acid, right? Nothing else works.

Here is "normal" exhaust water for comparison to yours:

 

[FLokiDk]

I'm in the Caribbean, any idea where

Is your water heater plumbed to the thermostat bypass, such that coolant hoses to the heater go over the engine? If so, that's the highest point. I installed a bleed valve there. If your heater connects to the heat exchanger, and no part of the system is above the coolant cap, then the system bleeds automatically with the coolant tank cap off. I doubt that's it, though.

I doubt it's the fuel filter, I have run 2 micron primaries for years.

The heat exchanger was "boiled out" with acid, right? Nothing else works.

Here is "normal" exhaust water for comparison to yours:

The water heater is removed.
I had the heatexchanger sit in vineger over night, flushed with water with baking soda, and rinsed in fresh water ... It was very clean, new anode installed.
The water comming our looks the same, I will compare more specific once Ive assembled everything again.

 

[Christian Williams]

What's the overheating temperature? It gets kinda subjective, mine maintains 180F with a clean heat exchanger, but 190 isn't considered bad, and under full power for an hour a bit above that is probably OK too. 200 F is said to be too hot.

Many folks can't run wide open throttle for long, overheating occurs--but cruising speed , maybe 80 percent, keeps to the usual temp. Bottom condition or prop choice might have affect, or trying to maintain speed against headwind.

The vinegar job might be fine, but alas, maybe not. Most people use phosphoric acid or other marketed products. More here and see comments:

Marine Diesel Cooling System Upgrade 2020

Symptoms: Apparent decrease in water volume at exhaust. Temperature RPM limitation at Wide Open Throttle. Steam from exhaust at idle. Solution: clean heat exchanger, optional general upgrade. When I took over Thelonious II four years ago, the boat would run at near seven knots all day at...

ericsonyachts.org

Master Thread on the topic:

Dreaded Universal 5432 running hot syndrome [Master Thread]

Hello All, I never motor very far, maybe a half hour or so at a time so I never really work the Universal 5432 in my E38 very hard or long. Well, I had to motor for about 1.5hrs on Monday to get where I was going and the engine ran pretty hot. Normally I don't run much above 2200rpm as I don't...

ericsonyachts.org

 

[Loren Beach]

Heat exchanger trivia: there was a change in the standard HE for the Universal 25, somewhere during the production run. Our '88 M25XP had the 3" HE, and I read somewhere that older model M25 (21 hp) had some overheating problems with the original 2" size HE, and Universal/Westerbeke made a change. Some owners of these engines later also changed to the larger size.
I have no idea when the vendor may have made a change.
For the other/larger displacement blocks, this may have never been a problem. Maybe.
My SWAG is that all the engine suppliers spec out their engines for "barely enough" cooling capability plus a bit extra for slime build up, but not very much.
Best of luck in your trouble shooting!

 

[Tin Kicker]

How smoky is your exhaust and do you have good water flow in it?

 

[FLokiDk]

What's the overheating temperature? It gets kinda subjective, mine maintains 180F with a clean heat exchanger, but 190 isn't considered bad, and under full power for an hour a bit above that is probably OK too. 200 F is said to be too hot.

Many folks can't run wide open throttle for long, overheating occurs--but cruising speed , maybe 80 percent, keeps to the usual temp. Bottom condition or prop choice might have affect, or trying to maintain speed against headwind.

The vinegar job might be fine, but alas, maybe not. Most people use phosphoric acid or other marketed products. More here and see comments:

Marine Diesel Cooling System Upgrade 2020

Symptoms: Apparent decrease in water volume at exhaust. Temperature RPM limitation at Wide Open Throttle. Steam from exhaust at idle. Solution: clean heat exchanger, optional general upgrade. When I took over Thelonious II four years ago, the boat would run at near seven knots all day at...

ericsonyachts.org

Master Thread on the topic:at

Dreaded Universal 5432 running hot syndrome [Master Thread]

Hello All, I never motor very far, maybe a half hour or so at a time so I never really work the Universal 5432 in my E38 very hard or long. Well, I had to motor for about 1.5hrs on Monday to get where I was going and the engine ran pretty hot. Normally I don't run much above 2200rpm as I don't...

ericsonyachts.org

Overheating temp is when we saw damp from engine around 200. It seems to come from the hose attached at the very top if block as a pressure relieve thing I guess since it's open ended. I read the two links, today we will test it again, and then look at freshwater pump/thermostat if we can find gasket for those.

Thanks for the input buddy, much appreciated

Torben

 

[FLokiDk]

W

How smoky is your exhaust and do you have good water flow in it?water f

 

[FLokiDk]

Water flow is good, it's a very thin mist disapearing on the air after 2 meters.

 

[David Grimm]

V belt adjustment ok? Thats what turns the internal water pump for the coolant. I run a 160 thermostat. Never see her go over 165. Raw water impeller new? Check the elbo to the raw water strainer. Many times I would have to remove inlet hose to raw water pump and hook it to the dock hose thus sending fresh water reverse flow through the strainer and out the bottom of the boat. This takes care of things you can't see in the line. Like plastic bag pieces and such. I keep a fitting on board for this at all times. I've had to use my anchor wash down hose on occasion.

 

[Puget sailor]

A thin mist does not seem like good water flow at all, or are you describing the exhaust gas? Water should be pouring out the exhaust in big splashes intermittently even at idle, assuming a water lift muffler of course, and a substantial spray of water at speed, mixed with the exhaust.

One thing you have not mentioned checking is the raw water pump, which has a replaceable rubber impeller inside. Every few years pop in a new one. If neglected they can wear away or fins break off and clog things up.

trouble shooting flow chart for cooling something like this:
Raw water coming in?
Raw water getting pumped to heat exchanger?
Raw water exiting heat exchanger?
Raw water getting into and out of mixing elbow?
Raw water coming out exhaust with vigor?

Coolant flow through engine, check pump and belt, thermostat, and check for air trapped inside engine or heat exchanger at high points, and sufficient coolant in expansion tank.

Another potential trouble spot is the heat exchanger itself, which can be partially clogged up limiting thermal exchange between raw water and coolant. Possible to clean or replace, but check everything else first.

that’s assuming this is a fresh water cooled engine with both coolant circuit and raw water circuit. If it’s a raw water cooled engine there is no heat exchanger etc, but there are still two pumps, thermostat, and mixing elbow.

 

[FLokiDk]

Another update... Would appreciate comments on handling the trapped especially. Here goes:
Latest update, nothing changed... But, I did press down a hose that had one loop before going into the heatexchanger, where the loop/coil rised higher than the exit of the coolant resovoir... I pressed it down being a bit confused that I could not sense a temperature change on heat exchanger when laying my hands on it after 20 min idle and temps reaching around 75... Almost the very second i pushed the coil down below exit from coolant resovoir, I felt a change in temp on the heat exchanger, I crawled out to tell Nick the find but he already stopped the engine since when I did push the hose down he registered a jump from something like 80 to 100 plus celsius. But I think we may sort of have narrowed it down to air in coolant circuit, or thermostat fucking up, with my bet on the air bubble

 

[Puget sailor]

Hard to say if you have a coolant air bubble big enough to effect heat exchange without seeing a diagram of the layout. But here are some notes to guide things:

The reservoir is an expansion tank designed to allow coolant to expand when hot and contract as it cools without impacting the pressure inside the coolant circuit BEYOND THE LIMIT set by the radiator cap, which is a pressure check valve. That’s usually set by design at something like 8-15 psi. The reason is that the boiling temperature of the coolant is higher under pressure. Beyond that pressure some coolant can escape to the reservoir, and when the engine and coolant cools and contracts, it can be pulled back in, since the cap is also a check valve and only pressure restrictive in one direction.

What that means is, if the hose connections between the radiator cap (on the engine, there is no “radiator” but it looks the same as a radiator cap) -that hose needs to be air tight between engine and reservoir or air can be sucked back into the engine instead of coolant, or if the reservoir has not enough coolant, same thing.

One way to potentially remove air and fully charge the system with coolant is to open that radiator cap so air can escape. If there are any points in the system of coolant higher than the cap, (not counting the reservoir circuit which is often higher) they need to be cracked open too to let the air out. Simply having coolant in the reservoir will not allow it to flow back into the engine because there is some resistance at the radiator cap check valve, it normally gets drawn in by the vacuum of the contracting coolant as it cools off after shut down. Under normal circumstances, several cycles of heating and cooling usually self purges the air from the coolant system automatically, the bubbles escape to the reservoir, come out the top as air, and coolant gets drawn in during cooling phase after shut down. For all that to work, the hose connections need to be air tight and the radiator cap functioning properly, but they rarely fail.

it should be possible to feel the coolant temperature entering and exiting the heat exchanger to see if it’s at engine temperature. If it is, the likely culprit is the seawater flow through the exchanger, either restricted coming into the boat from the through hull, or from bad pump flow through the raw water pump, or a restriction at the mixing elbow. Barnacles, dead minnows, seaweed, can all restrict inlet seawater supply. Easy way to check that is to disconnect the seawater hose going INTO the heat exchanger and start the engine and see how much flows. Should be a lot! If it’s dribbling or something, that’s no good. If it’s a strong flow, the next check is the house OUT of the heat exchanger, since the internal tubes can clog up.
A high point in the sweater hose should not matter if flow level is adequate, the water would just push the air out.

A fairly sudden change in cooling function is most likely a seawater flow issue. I’ve had a little blob of seaweed get stuck in the intake of the through hull and instantly the engine behaves as you describe. Happened to me just this season motoring away from the dock through some floating rotting eelgrass. 2 minutes later I noticed steam in the exhaust, and temp was up around 200, way more than normal. There was flow, but not nearly enough, I had to run very slow to control the temp coming back in. Had a diver clean my intake screen, all was well. Made me want an alternative intake system plumbed in, maybe via the sink drain?

Bottom line, verify seawater flow first, it needs to be really strong flow all the way through to the water lift muffler. The mixing elbow hose (seawater coming from heat exchanger) is another easy place to verify flow of the whole seawater system, but only test that by disconnecting and dumping into a bucket for a couple seconds of course.

My guess is your inlet is clogged, or seawater pump impeller is shot.