'78 Ericson27 Atomic 4 Universal Overheating

[Peter]

Instructions for how to do the acid flush, along with a vast amount of other useful information, are in the "Manual" - https://moyermarine.com/product/serv...erhaul-manual/

A must have for an A4 owner.

Peter

[JOHN COOKSON]

If it turns out that the manifold is plugged up after acid flushes and the bypass is blocked skip reaming with a screwdriver. Instead run water through the manifold at city water pressure. It will remove any plugs and the manifold water passage will be squeaky clean. You'll be amazed at what comes out.

TRUE GRIT

[CajunSpike]

I'll be the first to say that its entirely possible the screwdriver didn't do anything. I included that because it happened. Its also just as possible that the strong volume of water moving thru the exhaust manifold for my test flushed it out since the outlet was completely open and unrestricted.

[chrisoelder]

If it turns out that the manifold is plugged up after acid flushes and the bypass is blocked skip reaming with a screwdriver. Instead run water through the manifold at city water pressure. It will remove any plugs and the manifold water passage will be squeaky clean. You'll be amazed at what comes out.

TRUE GRIT

I like that idea. Are you thinking just a hose and a nozzle?

I think i will do that with the block also. My engine is pretty dirty and could use some cleaning.

Is anything I should be concerned about when doing this?

Thanks!
Chris

[Peter]

Instructions for the fresh water flush are, you guessed it, also in the manual.

Basically you make up an adapter that allows you to connect a garden hose to the block drains located below the alternator and the starter.

Amazing what comes out when you do this.

Peter

[chrisoelder]

Excellent!

My plan of attack has changed a bit from before

Step 1 - Find the issue of where in the cooling line is clogging OR determine if my pump is bad.
Step 2 - If the pump is good, bolt off the bypass line to the themostat housing
Step 3 - Start the processing of completing an acid bath. It probably hasnt been done in a decade.
Step 4 - After finishing the acid bath, clean out the engine with fresh water.
Step 5 - Run the engine for about a hour to get the raw salt water flowing through

I feel that this plan of attack will help me determine what the issue is and resolve it at the same time.

What do you all think?

[Dave Neptune]

chrisoelder, good idea skip 4 and just go to 5 the salt water will rinse just fine.

Dave Neptune

[JOHN COOKSON]

I like that idea. Are you thinking just a hose and a nozzle?
Thanks
Chris

Attach a hose from city water to the manifold inlet or outlet barb. Attach a tube to the other manifold inlet\outlet barb and direct it to the cockpit. When I flushed my manifold I did a reverse flush - that is the opposite to the away the water normally flows. That said I really don't think it makes any difference which end of the of the manifold you use as the inlet because so much water will be forced through it.
It is a good idea to have a valve on the boat near the inlet that you can open gradually as you keep an eye on it. That way if something bad happens, like a hose popping off a barb, it won't be as big of a mess.

TRUE GRIT

[marginal]

I think #2 is something you need to do, not a step in the debug process.
If you have no thermostat, you need some restriction in the bypass line to make sure some water is going through the block.

If it were my engine, I'd put a bolt or a valve in the bypass first, then see if the problem went away before doing any of the other things.

Simon

Excellent!

My plan of attack has changed a bit from before

Step 1 - Find the issue of where in the cooling line is clogging OR determine if my pump is bad.
Step 2 - If the pump is good, bolt off the bypass line to the themostat housing
Step 3 - Start the processing of completing an acid bath. It probably hasnt been done in a decade.
Step 4 - After finishing the acid bath, clean out the engine with fresh water.
Step 5 - Run the engine for about a hour to get the raw salt water flowing through

I feel that this plan of attack will help me determine what the issue is and resolve it at the same time.

What do you all think?

[chrisoelder]

RESULTS!

On Saturday morning I did the following:

1) Capped off the thermostat bypass

2) Performed the acid bath
2a) For the first 10 gallons the water was BLACK. After running another 2.5 gallons I started to backwash the engine.
Here is an image of the water

https://drive.google.com/open?id=1-ceUqrPHPgSDgSOHb_Vd6VIpFw0NEGRm

2b) I backwashed about 20 gallons of fresh water through the engine until the water was coming out was clear on the water pump end.
2c) After that I flushed out the exhaust line
2d) Ran the engine for an hour with raw salt water and she ran clean and cool with a lot of water coming out the back. Made me very happy.
Here is a video I took

https://drive.google.com/open?id=1ukSp8L8Jm2jl-rQT4UaDUctLJU1OywIn

3) Checked the impeller and pump, they seemed to work perfectly.

On Sunday a buddy and I decided to do a 5-6 hour sail through the Santa Monica Bay. The engine started right up and was pumping a lot of water (like Saturday). After warming her up for about 10-15 mins we headed out the slip. We motored around the marina for about 15-20 mins to test out the engine, everything seemed fine. We raised the sails and began to sail around the bay.

About 5 hours later and about 15-20 mins from the breakwater to the marina I decided to turn on the atomic 4 while going about 4.5-5 knots with low swells and with the heeling of the boat on the thru-hull side. I kept the engine in neutral with the lowest amount of RPMS (throttle). I wasn't seeing a lot of water coming out of the exhaust but thought it might have been an illusion from the swell. I kept my eye on it and then right before we hit the breakwater (about 20 mins after starting) I could hear the engine struggling so I turn off the engine. Opened the compartment, and there was some white smoke coming from the oil cap area. Without a doubt overheating again. After sailing for about 30 mins to my basin. Kicked the engine over to get us into the slip and she turned right over with the same water flow I had Saturday and that morning. After getting into the slip I kept the engine running and she was running a lot more even and cool.

I decided to turn off the engine to investigate. While looking around I noticed that my thru-hull comes to a T right after the valve. The line not running to the water pump runs to another valve then up to my deck where I can attach a hose to clear out the exhaust (I'm a dummy and didn't realize what that was while doing the acid bath). Once I found it I attached my hose and cleared out my exhaust line, why not right. But when doing that I realized that valve was open. Could this valve being open cause the pump not to get enough pressure to suck in enough water for the engine while under sail and moving 4.5-5 knots?

Here is a video of my thru-hull set up (black hose runs to the water pump and the clear runs to the fresh water hose line with the valve closed)

https://drive.google.com/open?id=1h3HX0hKQtGVfhoDSIrl6w1tAYX91ZP2G

SIDE QUESTION: Does anyone know what that other thru-hull is with the white hose?

Here is the engine running at different RPMs with the valve closed after washing the exhaust out

https://drive.google.com/open?id=16zglsp7pRmeG57QNFaFobY9AMhiviH3f

Could that valve being open be the issue of the overheating in the bay? I am a little perplexed by this situation. Runs great in the marina, has a tough time running in the bay while sailing.

Let me know what you think! Making a lot of rookie mistakes going to learn from them.

[CajunSpike]

A pump will suck from whatever source is the easiest to obtain.
Sucking air from an open air line is certainly easier than water from the bottom of the hull. Also when the boat leans and moves, there is less water pressure on that hull opening, by a small amount. Same idea as an airplane wing.
Could be just enough for the air to be ingested from the open air line.

Definitely worth a try to close the air line and try again.

Good job on the flush.

[chrisoelder]

A pump will suck from whatever source is the easiest to obtain.
Sucking air from an open air line is certainly easier than water from the bottom of the hull. Also when the boat leans and moves, there is less water pressure on that hull opening, by a small amount. Same idea as an airplane wing.
Could be just enough for the air to be ingested from the open air line.

Definitely worth a try to close the air line and try again.

Good job on the flush.

Thank you for all the help @CajunSpike! That makes a lot of sense. I will test it out and see what I find. I am hoping it is something as simple as this. I should be able to test it this week.

I am open to hearing any and all suggestions on this issue.

[chrisoelder]

Still overheating

Alright, so tonight the girlfriend and I decided to go on a harbor cruise/sunset sail. I ensured that the hose valve was closed so that the pump wasn't sucking air.

She started up great and ran like she normally does. Was pushing a lot of water out until we hit a very light chop in the channel then I noticed the amount of water coming out of the exhaust was almost nothing. Decided to check the engine and she was getting warmer than she should. Also noticed a gurgling sound near the thru-hull where it splits with a T barb. One hose heading to the water pump and another hose to the deck, here is a video I took on Sunday of my thru-hull setup. The black hose runs to the water pump and the clear to the deck.

https://drive.google.com/open?id=1h3HX0hKQtGVfhoDSIrl6w1tAYX91ZP2G

I figured that was my culprit and that, even with the valve closed, it was not enough suction pressure for the water pump to suck up moving water from the bottom of the boat.

I went to home depot and got a closed cap barb to close off the side of the T that doesn't run to the water pump. Opened the thru-hull (no leaks) and kicked over the engine. I didn't notice much of a difference in water flow then I normally do when starting her at the slip. I wasn't able to take her back out into the marina for more testing.

Could this just be a thru-hull issue or could my water pump be bad? Do other boats have a T bard after the thru-hull?

The overheating seems to be happening at higher RPMs, quicker speed over water, and not still conditions.

[JOHN COOKSON]

, even with the valve closed, it was not enough suction pressure for the water pump to suck up moving water from the bottom of the boat.
Could this just be a thru-hull issue or could my water pump be bad? Do other boats have a T bard after the thru-hull?
The overheating seems to be happening at higher RPMs, quicker speed over water, and not still conditions.

I was going to post this a few days ago but didn't because in post #11 you implied there was a lot of cooling water making it to the pump.
Here is my current theory:
There is sea life sort of blocking the water intake under the boat. At low RPMs the junk just hangs down and does not effectively block the inlet. At higher RPMs, as more water is being pulled into the engine, the junk is pulled up against the inlet by suction and effectively blocks the inlet.
I think it is past time to get a diver under the boat and get the under water strainer completely clear of all sea life. Also be sure the short pipe from the strainer to the valve is free of any sea life. I reamed the inlet pipe from the strainer out with a piece of rebar. That took care of the sea life that had set up condo living in the pipe real quick. You can do this while the boat is in the water: Just attach a length of hose to the ball valve and support it above the water line and run a piece of rebar or a screwdriver down through it.

TRUE GRIT

[chrisoelder]

I think it is past time to get a diver under the boat and get the under water strainer completely clear of all sea life. Also be sure the short pipe from the strainer to the valve is free of any sea life.

Thank you for your response!

This is an interesting though. So there could be something clogging it from the valve to the strainer. That would make sense that once we get going a certain speed the engine doesn't suck up any water, but at the slip we have great water flow. That would cause the gurgling sound when moving pretty quick in not flat conditions right? For example, after the acid bath I ran the engine for over an hour with only raw salt water and she was fine.

Video of the water flow at different RPMs

https://drive.google.com/open?id=16zglsp7pRmeG57QNFaFobY9AMhiviH3f

I just spoke to my diver, who cleaned the bottom last week, and he told me that he didn't see anything that would cause any kind of blockage but it is possible that something could be between the strainer and valve. He offered to come check it out on Friday. Would that be necessary if the clog is between the strainer and valve?

When you resolved your issue, did you just run your bilge pump or a shop vac as the water was flowing in while you were going at it with the rebar?

Here is an image of the bottom of the boat from April 12th, 2018. This is when i had the survey done, and my surveyor said that my thru-hulls were still in good shape. She is in desperate need of some paint, which will be done after I figure out this overheating issue.