2015 SAN 210 Warning 1415 / 1416 EMWT1 / EMWT2 over stage 1 limit

[LakesideRec]

Put my 2015 SAN 210 back in the water for the season and has run fine a few times under load surfing with full ballast and just boat-riding at speed. This morning, we went for a slow coffee cruise at idle the whole time and it came up with Warning 1415 and 1416 - Exhaust manifold temp was high. Water appears to be flowing OK through the inlet filter on visual inspection, but the fact that both sides are coming up with the error makes me think its low water flow out of the sea water pump at low rpms/idle.

Have a new pump impeller on order, (but have not inspected it yet). Will replace that and see if it helps.

Other posts talk about a firmware upgrade for the 2015 PCM boat, and that these warnings may be a false alarm, so wondering if anybody has details about that.

[H2O]

There may be an air leak in the cooling system. Check all hose clamps and especially the tightness of the water strainer bowl (make sure the gasket is present). Overheating at idle but not at load usually indicates air leak.

[LakesideRec]

There may be an air leak in the cooling system. Check all hose clamps and especially the tightness of the water strainer bowl (make sure the gasket is present). Overheating at idle but not at load usually indicates air leak.

Visually, at idle, there appears to be water flowing through the strainer, so it was not completely starved of cooling. But its only about an inch deep of flow in the strainer at idle. Should it be sucking all the air out of the strainer and filling it completely with incoming water?

Yesterday, I opened the strainer and checked the seal which looked fine. I cranked it down pretty tight when I closed it again. After that, in an hour-long test cruise at idle the whole way, the exhaust manifold overheat errors did not happen. The water flow didn't look appreciably different from before I reseated the strainer lid.

I did have the hose clamps off at the oil coolers on both sides during winterization. When I put it back together, the other week, I checked for any water leaking out, but didn't really test for air leaking in. I will go back and check that connection on the oil cooler on the inlet side.

Another thread mentioned that the exhaust manifold cooling passages can get crusty and obstructed inside. This boat was run in salt water for its first two years of life, so I wonder if there could be some corrosion inside the manifold obstructing the flow.

I imagine a marginal pump impeller would be that much more susceptible to any small air leaks or obstructions, so will still inspect (and likely replace) that when I get the part.

[H2O]

Use caution with the transmission cooler-- it is copper and if you tighten the hose clamps too much you can crush the tube ends under the hose clamps. Pull the hoses off and verify before reconnecting. Not certain but I think the strainer should always be full of water. Still sounds like an air leak. A bad impeller usually causes overheating under load, increased RPM and air leak overheats at idle but not higher RPM.

[scottb7]

H2O nailed it. I am impressed. Even at idle the strainer should have 0 air....should be 100% water. Wonder if you can put on garden hose at hour hose turn on full and find a leak...

[LakesideRec]

I think one problem was that the flush connection valve was open. There is no handle on the valve and I have not used it since I owned the boat, but it turns out it was in the open position. Its connected to a quick-connect inlet with a self-closing one-way valve, but the one-way action in the quick-connect is isuch that it would still allow air to suck in.

I also secured the hose onto the oil cooler with the hose clamp closer to the lip to form a better seal.

After those two changes, the strainer was more like 3/4 full at idle. But what makes me believe its completely air tight now is that the water desn't drain back out of the strainer when the engine is shut down.

Took an hour long sunset cruise at idle the whole way and no exhaust over-heat codes.

I will save the impellor swap for another day. Its not exactly a convenient thing to access.

[LakesideRec]

Well the saga is not over.

Kids had the boat out yesterday and experienced the error messages again. Swapped out the impeller in the sea water pump. Impeller I pulled out was not cracked or missing any piece, but was somewhat deformed and worn. Not sure if I dropped it, or it was missing, but the o-ring seal on the pump body may have been missing. Put the new one in when I re-assembled it. No leaks and holds vacuum. - Strainer filled up slowly at idle and stays that way when engine is off.

After the sea water pump impeller swap, started the boat and ran it at idle at the dock for half an hour. Had the EMWT1 and EMWT2 exhaust overheat errors, but this time also an "Aux Temp is high - most severe level" warning. This boat is a coastal edition, so part of the exhaust manifolds are cooled by the fresh water system. Maybe the problem is on that side?

[LakesideRec]

Checked the coolant level on the closed loop. At first it kind of fooled me because the resevoir was off the clip and not really sitting level - looked like it had coolant in it. But I opened some of the bleeding vents and nothing came out, so I decided to top it off.

Turns out it was about 3.5 quarts low by the time I refilled it and vented the air.

Watched it run up to temp at idle the dock and then top out at 160 degrees and then settle down to 150 as the thermostat opened. Took her out for a test ride mixed high throttle and idling. Stayed in a tight range between 145 and 155.

I had drained a small bit of the fresh cooling loop by accident when winterizing last October, but pretty sure I did not drain out that much. Wonder if it has just been slowly getting low or if I have a larger problem like a leaking gasket or crack - Maybe some freeze damage? I will monitor the coolant level and if it eats coolant, then I will know I have a larger issue to chase.

[LakesideRec]

Well, the coolant level is slowly going down as the boat gets used, so there must be some kind of leak in the closed cooling system. Nothing visible on the outside of the engine, and the small amount of water in the bilge doesn't smell like coolant, so the leak must be internal. My first suspect is the heat exchanger, and I am hoping its the culprit because it is the cheapest repair. Otherwise I am looking at the exhaust manifolds, head gaskets, intake gaskets, a cracked head, or a cracked block.

[LakesideRec]

I pressure checked the closed loop system today. It held 12 PSI for 30 minutes without leaking down that I could see on the gauge. If its leaking, its a slow leak.

While it was pressurized, I pulled the drain plug out of the seawater section of the heat exchanger and let it drain for a while. There was no hint of anti-freeze color or smell dripping out of the drain, so it doesn't seem that the heat exchanger is cracked.

Maybe there was just still some air in the system from when it was low and its slowly making its way to the reservoir. Will keep monitoring.

[scottb7]

Well it is a shot in the dark. But could be exhaust manifold thermostat.

I guess if i were you i would take a good look at water flow diagram and then take a hose off at various places to check flow after the pump. With engine not overheating you not gonna hurt anything. If you got good flow immediately after the pump then you know everything good to that point. etc.

[Infinity]

The ZR409/450 boats have 2 thermostats. The one shown in above service reminder....which is the fresh water thermostat, and also a thermostat that is in the closed cooling side where the DEXCOOL circulates (it is located at the bottom of the engine below the belt tensioner, also where the botto of the tube for your coolant overflow bottle connects to).

Is it possible that the coolant is leaking from the drain plug that you mistakenly opened on the heat exchanger when winterizing? If you have a colant leak....its also possible that one of the coolant hoses rubbed against something and has a pinhole. I would look for leaks while the engine is running just in case it only leaks under pressure?

[LakesideRec]

As I mentioned when I pressure test the closed system, it holds pressure when cold and not running. FYI, its an EX343, but thanks for the idea to look at how the thermostats possibly seal off the leaking section - mabe the pressure test is not reach everything when the thermostats are closed.

If its not actually leaking, it is kind of a mystery as to why it was more than 3 quarts low and then after I topped it off, it went down a bit in the overflow bottle from 3/4 full to about 1/4 (when cold). Maybe I over-filled it and it vented some of the excess? But that still doesn't explain how it got low in the first place.

I just purchased the boat last fall - maybe the previous owner made a similar mistake I did and drained the closed system more significantly when attempting to winterize?

[LakesideRec]

Update on this thread: Our 210 has run great for the past 2 months, until just yesterday my daughter was out and it overheated. The coolant was down a little bit (about 1 quart), but even after I topped it off, it when I tested it at the dock just in idle, it would slowly climb to 180 and trigger the overheat alarm. I noticed that although the hose going to the thermostat was quite hot, the heat exchanger on the other side was perfectly cool. So the thermostat was not opening.
I pulled the thermostat and tested it - according to the thermometer I had, it wasn't cracking open until about 180, and not fully open until well above 200. Seems like perhaps the thermostat has been marginal this whole time, or is perhaps just the wrong thermostat for the boat?
New thermostat on order and we will see if that solves the problem.