#1
IP: 50.168.135.40
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Milky water exhaust question??
Hi All,
I cleaned out my Groco ARG 500 raw water filter recently. The PO had it plumbed backwards, the "in" side was closer to the pump and "out" was closer to the incoming thruhull valve. According to MaineSail's directions, I reversed that, replaced washers and cleaned the viewing container and basket. The filter had some grass in it but was not clogged as I expected it to be. As MaineSail had told me how the filter functions, the bits of grass were in between the filter basket and the viewing container. I've had the boat 5 yrs and have not cleaned this filter til a week ago. NOW, immediately after this change and cleaning, the exhaust water is looking like very watery milk. It was almost clear before. Prior to this change , the exhaust water would have a couple of spurts of watery milk immediately upon startup but then would go clear. Now it's watery milk the entire time the engine is running. ALSO, prior to this change there would be a small amount of oil smoke upon startup but it would clear within a minute or so. Now there is some oil smoke the entire engine run time. The volume of water exhaust is the same about 2 1/2 gals. What is going on??
__________________
Barbara L. Hickson Flight Risk C&C 33-1 Chas., SC |
#2
IP: 96.253.21.28
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If the only change you made was reversing those connections, then the change must be related. Is your engine raw water cooled?
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#3
IP: 96.253.21.28
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If the engine is raw water cooled, you may have changed both available pressure and flow to the castings. This could cause a "cleaning" of salty deposits which could then be seen downstream in the exhaust. If this made the engine run colder, tolerances could change and let more oil past rings and guides.
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#4
IP: 216.115.121.240
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Hi Barbara,
Is there an oil sheen on the water? If not, this "milkiness" is maybe some thing else. What? Does it dissolve in the water after it drops in? One idea in my little head was; maybe it's air entrained in the water. Perhaps from a small leak in the hose or seals in the strainer. Grasping at straws here. Collect the discharge in a bucket and get empirical evidence— just what the heck is it anyway?
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Whiskeyjack a '68 Columbia 36 rebuilt A-4 with 2:1 "Since when is napping doing nothing?" |
#5
IP: 71.118.13.238
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Like Russ stated save a bucket of the discharged water and let it sit. What you were noticing was probably just tiny bubbles being forced into (airieated) the water from the exhaust gasses and water being mixed a bit better or different. If not the oil in the water will rise to the top of the bucket!!
Good luck! Dave Neptune |
#6
IP: 161.213.49.150
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If you are feeding the manifold from the high end with water comming out the low end reverse this so water goes in the low end of the manifold and comes out the high end. I think you will be happier.
Search the forum by the word "THATCH" to read all about it. TRUE GRIT Any chance there is a crack in the manifold and exhaust is mixing with water in the manifold? There may be a manifold pressure test in your near future. I don't like this idea too much because water usually ends up in the engine if there is a crack in the manifold. Last edited by JOHN COOKSON; 02-27-2015 at 01:31 AM. |
#7
IP: 50.168.135.40
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HanleyClifford: yes, it is raw water cooled. What are "castings?"
The ambient water temp is such that I am not sure if the operating temp gets to normal after 30 mins of run time at dock. Lat64: No oil sheen; water collected in bucket appears to be clear EXCEPT for what appears to be a slight gasoline sheen on top, very greasy but its not oil. JohnCookson: I have searched "Thatch" and many posts appears, primarily regarding converting to fresh water cooling. I do not know the "high end" of manifold from the "low end". I do know that my A4 is a v-drive and, from talking to Ken at MM, the usual bow end of engine is the aft end. I will attempt to post a picture. Thanks for the help you guys! I compression tested the engine about 4 years ago and got great marks on all 4, in the 100-114 range for each of the cylinders. Don't know if that is "wet" or "dry" readings. The picture uploaded and the Groco filter is to the left of the engine. Is this the high end or low end of the manifold? I'm afraid of what this foretells.
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Barbara L. Hickson Flight Risk C&C 33-1 Chas., SC |
#8
IP: 68.111.11.84
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Unless your engine is dead level in the boat one end of the manifold is higher than the other end.
Here's the concept: If you introduce water into the high end of the manifold it will run down through manifold and leave air pockets. This happens because the internal diameter of the manifold water passage is more than the diameter of the inlet. If you introduce water at the low end of the manifold it will push air up and out as it rises up through and out of the manifold high end. Result: Better cooling of the manifold. TRUE GRIT |
#9
IP: 216.115.121.240
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I'll focus on the water pollution and let others help with the plumbing.
So,.. The way I understand it, the white-ish water goes into a sampling bucket and then clears up, but has a bit of exhaust "crappy slime" floating in it. Is that correct?
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Whiskeyjack a '68 Columbia 36 rebuilt A-4 with 2:1 "Since when is napping doing nothing?" |
#10
IP: 108.41.166.138
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The castings are just the internal passageways through which the cooling water flows. With the old flow, an equilibrium was established between the flow and the crud that built up in those passageways over the years. Change the flow, upset the equilibrium for a while, cause some crud to be displaced for a while until a new equilibrium is established.
I have a v-drive too and have not done the simple "thatch" modification to the manifold hoses...but for what it's worth I suspect the side of your engine with the v-drive on it is lower than the flywheel end - ie, the engine is pitched forward a few degrees. The flow through the rubber cooling water hose enters the manifold from the flywheel end of the engine and flows "downhill" through the manifold, then out the lower manifold cooling hose and to the standpipe or muffler. This has the potential to introduce bubbles in the flow and leave hotspots in the manifold but, I think, tends to leave less water hanging around in the manifold when the engine is shut off which is why I haven't done the thatch mod. Like lat64, I think the cloudiness is caused by an air leak in your strainer that is letting bubbles get into your raw water. I would take it apart and make sure all the gaskets are smooth, all the threaded fittings are taped or gooped and fastened tightly, and all the hose clamps are tight on the barbs. If you've ruled that out, you're positive you don't have water leaking OUT of any plumbing, and the engine is starting and running smoothly, frankly I would not be too worried about the cloudiness or the sheen. The sheen might be caused by a carb set a bit rich or an engine that isn't fully warmed up yet. What you're giving up in efficiency you might be getting back in ease of starting. |
#11
IP: 50.168.135.40
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Thanks for the help. I took the boat out yesterday since the plumbing "fix." There was good propulsion in lower rpms but decidedly not as rpms increased (barely making 3.25 knots with no current). The oprating temp was a good bit higher than usual as well.
The cooling water enters the pocket at the gear end of the engine, flows underneath thru a casting to another hose entering the water pump which pushes it into the manifolds. The gear end faces forward and sits lower in the boat than the flywheel end. I think at this point I should just put the raw water filter back the way it was. Gas may be leaking past the rings and I don't want to blow one. Gas never came out of the exhaust before and the temp never rose above 145 on the hottest days in Aug. I'm guessing the air pockets may be causing the lack of good cooling but why would fuel be getting past worn rings now when it never did before? Thanks.
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Barbara L. Hickson Flight Risk C&C 33-1 Chas., SC |
#12
IP: 50.168.135.40
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And she does start very easily!
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Barbara L. Hickson Flight Risk C&C 33-1 Chas., SC |
#13
IP: 50.168.135.40
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Yes Lat64 that is correct.
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Barbara L. Hickson Flight Risk C&C 33-1 Chas., SC |
#14
IP: 99.115.145.226
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Besides collecting some discharge and seeing what settles out, have you checked the dipstick for milkiness in the crankcase oil? If there is any trace of white in there, it's caused by water in the oil, possibly from either a crack in the head gasket (which can sometimes close up as engine temps increase) or a leak in the water jacket of the wet exhaust which allows water back into the crankcase oil. Have experience with both. Both are curable, but at some aggravation and expense. Send me a PM if you need more.
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#15
IP: 24.138.22.213
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Try taking one plug wire off at a time. If you pull one that doesn't change the engine rpm change out the plug. Restart and see what you have. Test same thing again and see if it make a change now....if so, dead plug was the culprit.
Sometimes a dead plug will leave a whitish residue and sheen on the water. If the boat is moving you may not notice the sheen so much. See if that does anything for ya.
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Mo "Odyssey" 1976 C&C 30 MKI The pessimist complains about the wind. The optimist expects it to change. The realist adjusts the sails. ...Sir William Arthur Ward. |
#16
IP: 68.111.11.84
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You can also feel the plugs. If one isn't hot it's not firing.
As you know if you suspect compression problems it's time for a compression test. How clean is the prop? I'm still of the opinion, until proven otherwise, that the increased water flow mentioned in post #1 is breaking KRAP loose in the cooling system and pushing it out the stern of the boat. Maybe an acid flush would be in order? TRUE GRIT |
#17
IP: 216.115.121.240
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I will pose this question to all knowledgeable parties:
Do you think Barbara could have a blown or leaking head gasket that causes the air(we think it's air) in the exhaust water? Would her higher temps be consistent with this theory?. That would account for a bit more oily gunk in the exhaust water too, maybe. Again, just grasping here, Russ
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Whiskeyjack a '68 Columbia 36 rebuilt A-4 with 2:1 "Since when is napping doing nothing?" Last edited by lat 64; 03-01-2015 at 09:26 PM. |
#18
IP: 107.0.6.242
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Quote:
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#19
IP: 24.138.22.213
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Might be unrelated...I'd be checking that all cylinders are firing first. The only time I've seen a whitish exhaust is a dead cylinder..raw fuel being pushed into exhaust stream. Easy to rule out. One of our members at our club had it once and checked fire to the plugs. Once he had done that he took it for granted that he had fire because the plugs were new and in the engine a month or so. Dud plug was the issue.
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Mo "Odyssey" 1976 C&C 30 MKI The pessimist complains about the wind. The optimist expects it to change. The realist adjusts the sails. ...Sir William Arthur Ward. |
#20
IP: 50.168.135.40
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I have not yet put the raw water strainer back the way it was. Just for clarification, the hoses remained the same, the strainer itself I turned 180 degrees) Instead, I'm going to 1) double check for airleaks around strainer parts/seals, 2) remove the gearbox cover and see what the oil looks like, and 3) check for spark on all 4 plugs.
I had planned to acid flush this spring but now might be better. I'm also looking up the symptoms of blown head gasket. Thanks and I'll keep you posted. Hope to get back to boat today after work.
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Barbara L. Hickson Flight Risk C&C 33-1 Chas., SC |
#21
IP: 198.11.8.218
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One more variable
A note of caution in diagnosis: Barbara has a vee drive which means that the gearbox is also in the cooling circuit. I don't have any experience here...
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Jeff S/V Bunny Planet 1971 Bristol 29 #169 |
#22
IP: 206.125.176.3
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Barbara, Hold off on the acid flush..we don't need to introduce more "fixes" until we try to solve the problem at hand.
The issue with no power at higher RPM could be an indicator of a plug not firing..any chance you got the wires out of order or knocked one loose (check the distributor end of the wires too!) while messing with the strainer? The "pull-a-plug" test is the next one I would do. Like Mo's friend, I've had bad plugs before, that I struggled and struggled with, and the solution was another $2 spark plug. Now, I simply replace them every season before spring start up.
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-Shawn "Holiday" - '89 Alura 35 #109 "Twice Around" - '77 C-30, #511 with original A-4 & MMI manifold - SOLD! (no longer a two boat owner!!) |
#23
IP: 174.237.33.242
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Gorgeous day here in Charleston! Must be 65 degrees.
I checked for water leaks and could tighten the clamps around the raw water I let thru hull quite a bit. The bilge underneath that was wet but is dry now with paper towel under for leak test. I can see through the strainer container and I don't see any air bubbles whatsoever. Regardless, I took her apart and taped and used plumbers grease on fittings and refit the thing. Checked all plugs with insulated glove and got plenty of shock still. All plugs changed rpms of engine when removing one at a time. The exhaust volume has not changed. It still looks milky but in the bucket, the sample clears and has a floating sheen still of gasoline. I have not searched for head gasket problems on this forum yet. I believe I'll go up to the marina office and see if they have any beer left from the weekend. The crew did not leave me any from Saturdays race.
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Barbara L. Hickson Flight Risk C&C 33-1 Chas., SC |
#24
IP: 71.118.13.238
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Barbara, a little sheen is fine!!! The engine may be a bit rich and was probably cold too. Look to this later!!!!!!!!
Lets find the heat problems and not worry about the exhaust water being milky looking from air incursion. Like Shawn said don't acid wash yet. Lets get the water flowing and find out where the restrictions are. Does your engine have a bypass valve rigged on it? If so get it out and work on flow~the manifold fittings are the first suspect as stated before~once cleared, time to look to the block which will not be difficult to "read" once the t'stat is removed. Once flow is established it will be time to determine an acid wash. Personally I would do a vinegar soak on the manifold when checking it, then the same with the block. This may shake some debris loose causing another restriction and it will probably show at the exit fitting again! Dave Neptune |
#25
IP: 12.172.250.194
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Bunny, don't worry, you aren't missing any nuances with the V-drive cooling system. Here's how it works: before raw water enters the suction side of the raw water pump, it runs through a metal tube that goes straight through the V-drive oil sump. That's it. There are barbed fittings on either side of the V-drive to allow the rubber intake hose to connect, and if the V-drive oil is hot, the tube cools it down.
If the hoses are clamped to the the barbs, which is almost certainly the case, the V-drive isn't part of this problem. |
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