Film\streak on water from exhausts, losing antifreeze too

[mrsrobinson]

1995 330DA Sea Ray with twin carbureted 7.4s with full system fresh water-cooling kits. Jasper Long blocks installed 09/05. Fill System San Juan Fresh Water Cooling kits installed before hour 5 on each. Fresh to brackish water use.

We are losing antifreeze, about 1-2 cups each engine per1 hour of use (cruising speed). Bilge is clean, no green antifreeze. Mechanic thought it might be the riser gaskets so they were replaced about 3-4 hours ago. Same result still losing antifreeze. This summer, after coming down from cruising speed onto plane we occasionally smelt antifreeze.

We changed the oil last week and have sent samples to Blackstone laboratories. Hoping there is no antifreeze in the oil. We ran the boat last weekend for about 30 minutes, enough to warm up the oil for the change. Changed the oil and filers and went home.

Went down today and both antifreeze reservoirs were empty. I filled them up and started both engines. I noticed a film on the water. Hard to see since our water is very brown, but it almost looked milky white. It's thin and spotty, not a lot. I put my hand in it a few times and could not smell anything.

Both engines fire up after 4-5 seconds. The port one will puff bluish smoke for a few minutes. The port one will also start steaming after about 5-10 minutes at idle speed.

Is this film on the water normal after only sitting for one week? It goes away after a few minutes of idling and it's not a lot. 2nd, what else can we look at for the source of our antifreeze leak\loss? And finally, what's the source of the blue smoke (or what should I look at). Any of these symptoms point to loosing antifreeze?

Thanks






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[Dave M.]

An interesting set of symptoms. As you know already from my photos, I have a 96 7.4L carb engine, also with full San Juan cooling. Only my cooling was installed after many hours of use.

When you say the port engine steams after 5-10 minutes at idle, where is the steam coming from, off the engine, or do you mean out the exhaust?

Blue smoke on startup to me would indicate possible oil leaking down past the valve guides when the engine is turned off. When you start the engine, it burns out, and should not leak enough to be visible when running unless very bad. But you should not have this problem with a good rebuild. I don't know if blue smoke can indicate antifreeze where it should not be. Leaking valve guides should show up during an engine compression check.

You don't mention what your engine temps are running. Mine runs about 170, within a few degrees. It might drop back down to 160 after coming off plane and idling for 5 or 10 minutes.

The fact that you did smell antifreeze when coming down off cruise speed, and you are losing it consistently, suggests to me it is being blown out somewhere. When the engine gets hot running, the coolant expands and has to go somewhere. It should go by the pressure relief in the heat exchanger cap, and be caught in the reservoir. Do you know if this is happening? Is it possible you have the wrong caps on the heat exchangers, so it can't get out there?

Another question, do the coolant lines go elsewhere in your boat? Mine go first to the hot water heater on the port side, then across to the cabin heater farther forward on the starboard side, then back to the engine. If you have a similar setup, then one of these things might be leaking. But I would think anything like that gets engine heat from only one engine, so it would not explain both losing coolant.

Last idea, are you sure you are losing coolant? I think that with the San Juan kit, it takes a few, or more than a few, times of topping off the coolant before you really get all the air out of the system.

If you study the design and operation of the thermostat housing on the FWC engine, you will see that it is really sort of a two-plane manifold, upper and lower. Air in the lower plane, from the engine circulation, will bubble up to the upper plane and be sent out the exhaust. So it actively purges air from the system. I think the FWC system, at least from San Juan, is not so good about getting the air out.

Do you have both risers and elbows on your system? And if so, dare I ask that you are sure that the gaskets with no coolant holes in them are at the location separating the fresh water coolant from the sea water (normally the gasket between the riser and the elbow)?

I know you have already found the leaky plastic elbow problem on your exhaust manifold bottom.

It this continues to be a difficult to find problem, and you are sure you ae not just topping off the system as air finds its way out, then you might consider getting some good flexible coolant hose and temporarily converting to a half system instead of a full system and see what happens.

 

[Dave M.]

Thought of something else. When I did my system, I was not happy with the hose alignment in a few places using the San Juan supplied hoses. So I went to my local Napa store, and browsed around their hose supply. I found some coolant hoses that had bends that better matched my needs. I did this so I could be sure I would not end up with kinked hoses. So I would ask, have you checked all your hoses now that they have been installed a while and made sure they have no restricting kinks in them?

If you have adequate cooling to the manifolds and risers, then they should get hot to the touch when running on plane, and after backing down. But they should not be so hot that you can't touch them for a moment or two. They should not burn you.

 

[mrsrobinson]

The steam comes from the exhaust out the hull.

We had a local mechanic install both kits. I have checked all of the hoses, no leaks. He too used some custom hoses as he did not like what was supplied.

Port engine runs around 165, starboard around 170. I think we have a bad impeller on the starboard engine as she heats up a bit when coming off plan and the exhaust water flow at idle appears to be less. Manifolds and risers are warm to the touch, never hot. Using a heat gun all over the cooling system I never see anything over 150 degrees.

I think the port engine heats our hot water tank, no cabin heater like yours. All of these lines are leak free and we never see green in the bilge.

I thought the source might be no overflow reservoirs, so I purchased and installed those recently. Fill them up to the cold mark, boat for an hour, leave, come back a week later, they are empty. So I know those are working. The plastic overflow kits came with a new ring seal for the radiator caps. I noticed since installing the overflow bottles and the new ring seal the radiator caps have turned zincy looking in color, almost like they are corroding.

 

[Dave M.]

The steam comes from the exhaust out the hull.

I am not a mechanic, still, I don't like the sounds of that. I would have a mechanic take a look. Maybe it is a bad head gasket, and you are getting coolant into a cylinder. Or a cracked block, but a reputable rebuilder, which I think you have, would magnaflux the stripped block before putting it back together. So that should not happen.

Manifolds and risers are warm to the touch, never hot. Using a heat gun all over the cooling system I never see anything over 150 degrees.

If you have a 'full system', then most of the exhaust parts should be fresh water cooled, and be the same temp or hotter than the coolant. That is 165 to 170, and I would consider that hot to the touch.

I thought the source might be no overflow reservoirs, so I purchased and installed those recently. Fill them up to the cold mark, boat for an hour, leave, come back a week later, they are empty. So I know those are working. The plastic overflow kits came with a new ring seal for the radiator caps. I noticed since installing the overflow bottles and the new ring seal the radiator caps have turned zincy looking in color, almost like they are corroding.

I don't understand this one. My cooling kit came with overflow reservoirs, so I would think yours would too. So the mechanic would have installed them to begin with. With no overflow reservoir, there is not place for the coolant to go when it expands, except past the pressure relief in the heat exchanger cap and out onto the engine or into the bilge. You would probably smell that.

I'm liking these interesting problems. Maybe means I should quit being retired and go back to work. :smt009

 

[mrsrobinson]

All the local mechanics and old salts tell me the steam is normal and to not worry about it. I see steam occassionaly on some other boats but IMHO it's not the norm.

The same folks tell me the risers\manifols should be warm to the touch, not hot. You should be able to put your hand on them and keep it there. You can on ours.

Our San Juan Cooling kits did not come with overflow reservoirs, not sure why not.

Yeah, I am worried about the head gaskets too. We changed the oil last weekend and sent oil samples for analysis to Blackstone Labs. Hoping to get the results bakc this week.

I enjoy working on the boat and problem solving too, especially this time of the season when we are not using her as much. I simply wish we had more room in the engine compartment.

 

[fwebster]

I've been reading along with you guys and have an observation or 2.........

The engine with that circulates its coolant thru the water heater heat exchanget will run slightly cooler than the other one just because there is more coolant volume to dissapate the heat.

Steam from the exhaust is normal in a FWC boat. It has more to do with the temperature differential between the cooling water exiting and the air temperature immediately around the exhaust port than anything else. I have seen more steam on one side than the other, then reverse course and see the steam level move to the opposite side because of the sun's elevation or wind direction.

If you are contiually losing coolant, check everything including transmissions and fuel coolers if so equipped.

If the coolant level drops as the engine cools every time, a pressure test of the cooling system should be done. Pull the plugs after the engine cools and check them, and check for water in the cylinders after the engines cool. This will tell you the source of a leak but not the cause.

You also have one of the classic symptoms of a failed riser (elbow) or a manifold or a leaking riser to manifold gasket., except ( and I don't know the answer to this because I don't know how the San Juan system is designed) FWC engines usually only have sea water and not antifreeze in the manifolds and risers.

Sooner is better than later on this one............

 

[Dave M.]

According to my Clymer engine/outdrive manaul, all of the mid-90's engines that were V8's had full systems (ie exhaust manifold cooled by engine coolant) if they were FWC engines. The smaller engines were half system, and ran sea water through the exhaust manifold and elbow.

My San Juan system is the same way. I have fresh water cooling of the manifold and riser, and raw water cooling of the elbow. Mrs. Robinson may not have a riser installed. But now that I think about the post in the thread I started about the plastic elbow, I realize that the boat must be a full system. That pressurizes the exhaust manifold, and reveals the worn, leaky plastic elbow.

I think if the engines only recently had coolant recovery reservoirs added, then what you experienced up to that time is normal. I would think that every time you got the engine hot, it spit out some engine coolant if it was really topped off. The expanding water has to go somewhere, and it would normally go out the pressure relief in the cap. So that is what it should do. Then when it cooled, it would suck in air. Then if you checked it cold and added more coolant, the cycle would repeat. It does not mean you do have a leak, and it does not mean you don't.

When you put the coolant recovery reservoir on, then things change. It should capture the coolant as it expands, and let it be drawn back into the engine when it cools. If you engine had any air in it when you added the recovery reservoir, then that amount of coolant will be withdrawn from the reservoir and sucked into the engine when it cools. My assumption here is that the heat exchanger cap is the highest point in your coolant sytem, and any air will migrate there. Then when the pressure builds enough to force open the relief valve in the cap, the air will be the first thing to be expelled.

This does not mean ALL the air will be expelled, just the air that is there available at the heat exchanger when the coolant is expanding. The system may be better at trapping air for removal or expulsion than I thought. I'm going to go take a second look, maybe will post a picture.

 

[mrsrobinson]

Frank, good call on the water heater and yes, the engine, Port, that runs 5-10 degrees cooler does heat the water heater. This engine looses more antifreeze then the starboard engine.

How does one check for water in the cylinders when pulling a spark plug?

I followed all the hoses yesterday. Looks like fresh water into the manifolds\risers and raw water out the elbows to the exhaust pipe.

We had the riser gaskets replaced 2 hours ago, no change in symptons. Some are telling me with FWC you need to add sealer to the riser gasets because of the added pressure.

Why are the radiator caps all corroded (silvery, like a worn zinc) looking now, since adding the reservoirs with the new seal for the caps (a much thicker seal)? I will try to get some photos this week.

 

[sr360aft]

This may be a stretch since you didn't notice any coolant in the bilge, but make sure your overflow/expansion bottle is large enough to allow for the expansion. I had an old Jeep once that I used a small bottle on (20 oz coke bottle actually). Upon cooldown, it would actually empty the bottle out and suck just a bit of air in since the coolant expansion (by volume) was more than the overflow bottle itself.

 

[Dave M.]

So, I went out, looked at the boat, and took these photos. Here is the water circulation pattern for the 7.4L FWC engine, regardless of whether it is factory or San Juan cooling.

Water is forced up out of the block at 1 by pumping action of the circulation pump. It enters the thermostat housing,2 (barely visible), then splits and goes to port and stbd where it enters the exhaust manifold bottoms 3. Then if flows up through the manifold,and riser if there is one,to 4. From there it flows to a small input manifold 5 on the heat exchanger, water from both risers come back together at this manifold.

Then the water goes into the heat exchanger 6, and flows down and exits the heat exchanger on the bottom and goes to the coolant circulation pump on the front of the engine (7), not quite visible here. Then is it pumped back into the engine to reappear at 1.

In the middle photo you can see that the water drawn out of the heat exchanger comes right off the bottom of the unit. It should let the air remain on top.



So, any air that is in the hoses from the manifolds enters the heat exchanger at the top, and we would hope would stay at the top where it can bleed off. It would have to get pulled down through all the exchanger tubes to get back to the circ. pump. So I think the heat exchanger should trap the air well for extraction, if the air can get there.

But you can see that for air to get out of the block, it has to flow from the top of the thermostat housing down the hose and over to the bottom of the exhaust manifold before it can find its way back to the heat exchanger.

From the nearly missed it photo of the thermostat housing, you can see it is fairly tall, and the coolant fittings are right near the top. It might make sense any time the coolant is replaced to remove a hose here to help bleed air out of the system.

Also, in the first photo, you can see that the coolant hose fitting in the riser is not centered vertically, but near the top of the riser. Since there is a blocked off gasket at the top of the riser, air could get trapped here if there is much vertical space between the gasket and the coolant port. I am sure you could put the riser in either way up. For the FWC case, you definitely want the coolant port at the top end.

So, in my mind, it is still questionable how quickly this system can get any trapped air out of the block and into the heat exchanger where it will be removed. And if you don't get all the air out at first, it will come out slowly (don't ask me to define how slow!), and will appear like a coolant leak as you have to add more water. But there will be not trace of a water leak as there isn't one.

I don't want to talk anyone into ignoring a coolant leak here, but just to be aware of the system and how it might work when filling or refilling.

 

[never monday]

My 7.4 FWC Merc's have coolant in the manifolds, a block off gasket and raw water in the risers. Could one of these be leaking?

 

[mrsrobinson]

Oil analysis back from both engines...not good.

"High sodium in Port engine coming from antifreeze. Iron and chrome read high, possibly due to lingering wear in, possibly due to antifreeze damage"

Starboard engine, sodium level normal, high silicon and iron, lingering wear a likley source.

 

[Dave M.]

My 7.4 FWC Merc's have coolant in the manifolds, a block off gasket and raw water in the risers. Could one of these be leaking?

Sure they can leak. Either one could leak to the outside or leak to the inside, into the exhaust passage.

 

[mrsrobinson]

Just got off the phone with Jasper engines. Good news is we are under our 18 month warranty. Looks like we will be making a trip to the service shop this weekend. Man, this stinks.

 

[Dave M.]

Just got off the phone with Jasper engines. Good news is we are under our 18 month warranty. Looks like we will be making a trip to the service shop this weekend. Man, this stinks.

Hopefully it will be a quick fix for you, and they won't blame it on the mechanic that did the FWC install. If we had a lottery going, I would put my two bits on the head gasket square. Keep us informed.

 

[fwebster]

That or a cracked engine block is where I've been all along on this.............

The mechanic will end up doing the pressure test then checking the cylinders for water. Thats when the fun of negotiating the cost of the repairs starts, but Jasper has a good reputation. At least it happened in the winter.

Good luck with it

 

[mrsrobinson]

Port engine:

"GREG: Compare this report with the report on the starboard engine, and you can see that for the
most part they look the same. The one difference is sodium, which is a concern. We aren't sure what type of cooling system this is; if it's closed, sodium is coming from antifreeze. If open, it's from seawater. Either way, it shouldn't be there--unless you're using an additive that contains sodium in this engine but not in the starboard one. If that's the case let us know. Iron and chrome read high, possibly due to lingering wear in, possibly due to antifreeze damage. Caution!"

Starboard engine:

"GREG: If we'd found a high level of sodium in this engine too, we'd be inclined to think there's another, harmless explanation for it, like an additive. Since we didn't, we are concerned it shows a serious issue in the port engine. Silicon and iron were the only things reading out of line in the spectral exam from this engine, and both are likely from lingering wear in. We will look for improvements next sample. In the meantime, watch for loss of coolant in the starboard engine, and you may want to have that engine's cooling system checked"

 

[mrsrobinson]

Back from the boat.

I ran the engines at idle speed for 20 minutes. I checked all manifold\exhaust joints for leanks, none. Bilge dry and clean. Checked the oil with the engines running and stopped, clean, levels in-line, no smells, looked normal.

I then removed the radiator caps on both engines. I bumped both engines up to 1500 RPMs and let them run for another 5+ minutes. I shot a heat gun into both tanks. Starboards peaks at 168, good water flow, no bubbles. Port peaks at 165, good water flow, no bubbles. Port engine heats the hot water tank.

I shut the engines down and removed the overflow hoses putting a small amount of antifreeze from each overflow reservoir into a clear water bottle. Starboard antifreeze is bright green, clean and clear, like the original antifreeze. Port antifreese is brownish and cloudy looking. I have some photos and tried to upload them to yahoo:

http://new.photos.yahoo.com/volkl96/photo/294928803909414799/0

I alos added one as an attachment to this post.

I can email you the photos if you want to see them.

What does browish\cloudy anifreeze usually mean? Oil in the antifreeze?

 

[Alex D]

Link does not work ...

Sorry to hear all this trouble Greg!! :smt009

Brownish coolant could easily mean oil in the coolant, that would lead me to believe the head gaskets are leaking at least on that port engine.