How To Repair A Marine Engine With A Cracked Block

we have here a 5.7 liter Mercruiser engine with a crack block it's an internal crack we don't know where it is but we know it's internal because we have water in the oil and we made several tests but in the end we put five quarts of oil in the engine ran in an hour and came out looking like this this is set separating for a week now and you can see there's just a tiny bit of oil on the top the rest of it is just a little bit darker than milk we came out with we start with five quarts we came out with six and a half quarts so we know that there the water is getting into the oil we'd like to use this knw block seal but the problem is this is a boat engine on a car engine we spoke to these people and turns out that what this stuff needs to work in a car engine it needs to circulate through the engine it needs to get up to about a hundred and sixty degrees Fahrenheit and it needs a little bit of pressure to push it through the crack so that it it the pressure pushes it through the crack oxygen on the other side begins to seal it you drain the coolant system after twenty to thirty minutes and then oxygen on the other side the for about 24 hours finishes the cure the problem is in a boat engine we don't have a closed system what happens in the boat engine is that there's a pump in the out drive a small rubber pump it pumps water up to the engine comes in here it goes into this tube into the water pump and the water pump it goes through the engine the thermostat is under this housing right here and the thermostat lets it out through these two tubes a little bit of fresh raw water comes mixes with this and on this side it goes through the exhaust manifold to cool it and then out and then on the other side through another tube and the same thing so we have a couple of problems the first problem is that there is a small water pump in the out drive it's a piece of rubber and it has to have water to lubricate it if you run this pump run the engine with this running without water it'll run it up very quickly so the typical way to do that is to put what we call earmuffs on the out drive and run water through the normal out drive pickup and that's how you normally get water in the engine when it's not in the water so we still need to do that because the engine will be running and we need to keep that little impeller cool also that impeller is what drives the water up into the engine and out the exhaust manifolds when you keep those to cool so we need that circuit intact but we need to close circuit running through the engine if we just connect the in and the out and let it run in a circle the problem is it has to run 20 or 30 minutes and the engine will most assuredly overheat so how do we fix that first thing we made a trip to the local junkyard and got a radiator we just picked one out of a large truck so it was a large engine to make sure it was big enough and picked the easiest one to get out basically a truck that it'd already been scavenged quite a bit so we're going to put the water in the top hole on the upper left and come out the bottom right so in order to do that we need to take the input water that's coming from the out drive and let it go into both this hose and this hose so that it goes to the exhaust manifolds on both sides to keep them cool and then we need to this is the one that goes to the water pump so the when it comes out of the radiator it needs to go into this tube and into the water pipe and then it comes out of the engine through these two so we'll plug one of them and take the other one and put that into the radiator so it'll come one of these will be plugged will come out hot into the radiator out of the radiator and into this hose cooled down to the water pump so that means we're going to have to plug this one too so we're going to have to plug two of these holes actually three the input because the raw water is going to be going to these two hoses this one because we're going to be coming out of the radiator into this hose and this one because this will be connected to that one and will be opened the other one of course will be going into the radiator so we'll have a hose on that so there's a lot of plumbing involved here and we'll show you what we came up with there so we said we had three holes to plug the big one I'm going to plug with this inch and a half diameter pipe cap that I think I got this one at Home Depot the little ones I had trouble with the little ones we're going to plug with crutch tips that's what these are two sizes because there were two different sizes just chair sometimes they're called chair tips or anti-skid tips I've always called them crutch tips and then these parts we got these at Tractor Supply in their plumbing section this tea is going to be used to put the input the raw water input to the two exhaust manifolds and these two are going to adapt we have inch an inch and inch and a half diameter tubing we have to add to this puzzle and these are different diameters on either side so that's going to help us adapt the sizes of tubes we're going to do is connect the water input coming up from the out drive and the impeller down there to the two output hoses which cool the exhaust manifolds and take all the water right out the back so then take those off we had a little trouble with that one it actually came apart the screw came out that's okay we can fix it later [Music] usually I find you have to break the seal a little bit there before they're easy to slide off well they're never easy to slide off okay those are the two outputs this is the input well its raw water coming up from the outer I'd so that's what's that's that is what that's going to look like we'll put clamps on that and finish it up in a little bit okay I got this client fixed and put back on this clamp on and I remembered that the kmw block seal if I can find it there the kW Block C of the instructions on the back tell you to do all of this without the thermostat in place the thermostat is under here so before we can go any further and I get a bunch of hoses routed around here I'm gonna take the thermostat out we'll just set that aside turn this over and to make a little easier we'll just go ahead this has to come off anyway this is the hose that goes down to the water pump engine-driven water pump a little easier if we take these sensor wires off the shop and put it in the vise this and I've got the only way to get that little plastic thing out it's a plastic piece that holds the thermostat in is to put something here so that you can get above the plastic and then try it out and so I did that and I did break the little piece that was here there's a little piece that come came down here so I have to replace that that allows us to get to the thermostat and I pulled it out and I did that before there's also of course a little gasket underneath that I pulled out treat this out a little bit I'll leave it like that because you're supposed to run it without the thermostat in it and if this works and fixes the leak then I'll have to find a new one of these and I'll put a new thermostat as well might as well with this far into it use the old gasket no sense in wasting a new gasket well with the new one in after we finish this process so we're just gonna put that back in okay put these sensors back up so that we can use the gauges on the dash later on and the next thing we're going to do is plug them the best that we know since we're going to put the water directly into the water pump we need to plug where that normally comes from and we're going to use one of these but not the other so we're going to plug this one up with a crutch tip okay those are nice and tight okay and now I think we can again this is the water the raw water inlet that comes from the from the out drive outside the boat and we're going to be putting that directly into the exhaust manifolds to keep them cold or cooled anyway or at least prevent them for me from overheating I'm gonna need a clamp on that bit on I know there's already one there it's way down here this normally is here there yeah and tighten the clamp I'm plugging this one just like the plug that one this is the radiator I showed earlier that I pulled out of the truck at the junkyard but I did leave the hose on the output and it's down here so all I need to do is connect those two together yeah the radiator we will be going into the water problem so here is one of the Parts I showed earlier I got from tractor supply it works pretty well it's very well into this hose which is and the one that goes down into the water pump and also it's okay into the hose that comes on the radiator it's not a real good fit but it's good enough so I'll press those on and get the clamps put together so I have those two clamps tightened it's not a great fit but I think it's good enough that leaks a little bit that's okay and the last thing we need to do is get the hot water coming out of the engine into the top of the radiator it took a little coaxing but I finally got these hoses on this vinyl hose here is one inch it's a little bit smaller than the pipe here and then over on our radiator the same thing this is reinforced vinyl but it was a little small as well so I put those in a bowl of boiling water and got them soft and coax them to go over and now I just put some clamps on them I've added now a little pump this pump is dumping into oil jug and connect it to the screwed on top of the dipstick hole the oil so I'm pumping out all of the old oil and also water that has leaked from the crack into the oil sump I need to get all that out before we put oil in it and then we're gonna make this last connection from the hot water coming out of the engine to the in into the radiator we're going to make that connection next so again the nicely than here very nicely well maybe not so nicely but we'll make it work I'm sure the more astute mechanics among you have noticed that I have this radiator in here actually upside down and that's true that's because in my haste to get a radiator out of the boneyard before they close at five they ended up picking up one that did not have a plug in the drain hole so I have an opening here so I put it on the top so that it has a less likelihood to leak so I put a bolt in the hole I drove it in far enough that hopefully it'll block off the area where it normally comes out that hose but I also put a clamp on the hose and a bolt on the other end and a clamp so hopefully that'll be good enough to seal it up at least good enough to run 30 minutes or so well it's coming time to fill the engine of water well the particular radiator I picked did not have the pressure relief cap on the radiator like most cars and trucks today it's on the recovery tank and I wish I'd picked one with a with it on the radiator it would have been a little easier but I didn't want to have all of the recovery tank and it's tubing in the system so I just put it off and I forgot to plug that hole so water was coming out so now I have a bolt and a clamp on the hose that used to go to the recovery tank I think now we have a sealed system and we'll put some more water in it so now we have the hose back on the earmuffs we're ready to turn on the water which will give us water across the exhaust manifolds turn this on go start the engine and see if you have any leaks so we have the engine running and it looks like we have water circulating through the engine you can see it in the clear hose that we have here that's what we wanted to see run it a little bit longer and see if we'd have any leaks anywhere then we'll cut it off it's not really necessary as a part of what we're doing here but I decided that since I have the system closed it'd be a good time to go ahead and clean the system much as you would clean the coolant system of a car it's easy to drain it you put the cleaner in there and you cycle it through the engine but that's difficult in an open system almost impossible in an open system ring because it just would go right out the back and you can't recirculate it so since I can recirculate it now I'm going to do that now I bought something that's a little more aggressive it works in only about 10 minutes because the normal flush that most of the flushes that you buy need to run an hour so and if I ran in an hour so I'd get another quart and a half of oil in the oil I'm sorry water in my oil another quart and a half of water in my oil and I don't want to do that so I bought one that's more aggressive and only runs about ten minutes so when I take this apart and let some of the water out so that we can have reason a gallon of radiator plan cooling system okay we've finished cleaning the the coolant system we flushed it and ran it flushed all of that out so now it's it's empty put the plugs back in it we did find however that and we kind of expected that air wouldn't be enough to cool the radiator so the easiest way we found is to cool the radiator with water will show that a little bit later so we'll control the temperature with water also over here I'm not sure that I'm showing it we've put a thermometer so I can see that thermometers right on top of the hose and I can see what temperature approximately what temperature we're getting so what we're gonna do is per the instructions of this this block seal we're going to mix it in a gallon jug with I think it said three quarts of water mix that up we're going to pour it into the engine here it actually says radiator but that's for a car so it'll go right into the engine here we'll fill the engine up with water then we'll top off the radiator seal it back up and run it 20 minutes and to make sure it gets up to 160 ok the instructions say to shake it up and put it in three quarts of hot water we have a bucket of hot water here so actually I'm going to use a funnel for that because I don't quite trust myself okay so we're gonna shake that up a little bit and put that down in the engine which going in this pipe it goes through the water pump and on into the engine now we'll fill this up with water until the engine is full and we'll know that when it starts coming out the other side [Laughter] that's full so we'll hook this back together what and we'll fill up the other tube fill up the tube on the other side to complete the filter here right now that pretty hot spray that with water okay we're at 114 I'm not sure up the video capture it okay we're reading 143 on our little thermometer that's on the vinyl tubing but almost 200 on the dash gauge so I think the - gauge is more accurate than our little external thermometer so we're going to start cooling now [Music] we've been spraying for a couple minutes now check to that yeah we were nearly 200 we've come down quite a bit now sourcing we've kind of found a steady-state gear we have the the water spraying and kind of a constant grade and that seems to be senator we 17 minutes in now we're going to go for maybe maybe 23 years old we want to keep it the range is 20 to 30 minutes but we want to keep it to the low end of that because in our case some of this wok Co going to get into the soil and that's going to go through the oil system and you want to make sure we want to minimize the possibility of that's why I want to keep it to the minimum of the rain we've got the temperature down now we're coming up on or 22 and a half minutes so another that fun is that so shut the engine off begin pumping out the oil real quickly well we ran our 23 minutes drain the coolant out now we're returning the oil pump back on it connects to the dipstick here and the pumps over there on top of the battery and the company in the jug there just to get as much of the oil out once we get all of that out then we let it set for a day and put water back in it new oil and see if they crack the seal we're gonna leave this attached leave the radiator attached until we know that the graph is sealed wants to know that and they put it all back like it was and run some clear water through it to make sure everything's out and hopefully they will be done of course when we pulled the drain plugs and let the block sealer out of the engine and into the bilge it drained out the hole in the boat in the back we put a couple of 5-gallon buckets there so we capture that didn't want to get down on the ground and you can dispose of that properly now now all we have to do is wait to 24 hours well we let the patch set a little over 24 hours and then change the oil three times and it came out the last time came out looking fairly good so I think we have it sealed then after that took all the oil out filled it back up with water and if none of that water leaked out then we probably have a good patch let's go check that water was all the way up to about here and it's not in there anymore but it's still in this hose let's see it in there so I'm hoping that with just maybe some air that's settled out of it but the tests gonna be turned the pump on pump is connected to the dipstick hole here so if we pump out just kind of a little bit of Slurpee air will find the pump out water or not fine so so I'm going to stick the hose here turn on the pump and we'll watch and see what comes out if anything so I'm gonna say that was just I'm gonna say that was just settling the air out of the water that came out of the hose that kind of aerated and if it went through the crack I would have quarts of water here now so I think it's sealed so what we're going to do now is the pump ball is connected back up like it used to be so we need to put this hose back here this hose back to here and this hose back to here I think oh yes oh yes and this hose back to the right thing so we're going to work on now at least Lucent in the house oh I'll take this one off that's the last plug so now we have our key removed don't have anything on these so now we're at the point where we need to put the thermostat back in and the new thermostat so take out these two bolts right here and putting in a new thermostat and gaskets bolts are loose they're almost loose there again take the sensor sensor wires off so that we can get to it okay turn this upside down now and there are four parts the OL gasket out four parts to replace we have orgastic if that goes in first then the thermostat on top of that and this little diverter on top of that and then they ask first the little round gasket goes in then the thermostat and then when when this little piece of plastic goes in thermostat seated there it goes in there's a little tip that I broke off here it goes in with that tip there but there is a little notch right here that little notch goes in here and that's how you get it lined up correctly when the plastic piece is completely seated line up the bump with this notch here and when it's completely seated it'll be touching the thermostat down here but it will have a little bit of a raised right here and I've already cleaned this this already clean this surface off with a scrape whatever plastic part as I just showed is raised a little bit and it sits down in a groove right here and so I sprayed this groove out to make sure that it's clean so that it can accept that the raised part of that plastic so now we're ready to put the housing back last time I did this I put the gasket down first and I kind of got it misaligned so this time I put both bolts in the housing and put the gasket on the housing piece I'm holding and then put it down and get the bolts lined up in that way the gas can I know the bolts will be going through the gasket so I've got the bolts started now the thing in place reattach the sensor wires and now we're ready to put these hoses back in place that one goes back to that exhaust manifold this one goes the exhaust hole on this side I need to take this spitting out so I can put this one back where it was piece it out now this is the one that goes down to the water pump you might have noticed some string that appeared in the middle of the video and down here some tape we let this hose rub against this belt we noticed it before rubbed all the way through taped it up so we'd get through our testing and then put a string to hold it back I have a new hose to put on there now so I have these three hoses back in place and the clamps tightened but this is the one I wanted to replace there is a small hopefully the light can show there's a small bolt there it's a bracket have to take off and then another clamp at the bottom where it hooks onto the oil cooler well like every other rubber hose I've taken off it coming off wasn't in its plans of things to do today so I just took a razor knife and slid it where it was stuck and kind of had to peel it off so that one's done you want to make sure that the one I bought is the right one kind of line it up and yeah it looks like it is the right one so we'll put that on okay got the new hose hooked on down at the bottom where it hooks on to the oil cooler that was a bit of a challenge because it's underneath the motor by the way you'll notice my build is not real clean should always clean your build the reason is that when you drop your tools in clean builds they come up clean and you don't get your hands dirty at least not as dirty so keep your bilge clean and you keep it goes clean tighten up this bracket right here well there it is then we'll put this hose on so there we have the last one when I put these clamps on I always think about how am I going to access them to have to take them off I'm putting them on with a wrench but I might have to take them off with a screwdriver in a pinch so I always try to arrange these so that it's I have have access to get so now everything's back together all I need to do is remove the oil pump from the dipstick hole and fill it with oil I mentioned before that I think I'll show it to you as I unscrew my pump for my oil dipstick hold it this particular dipstick hole does have our dipstick tube has threads here so it you can put a it's basically a garden hose fitting but it does have kind of a deep throat to it so that this can go up into it and it'll seal here and that's how I'm able to pump out because it's made with this thread on it that stick goes back in here and put oil in it for those interested this is what my pump looks like I had one for years I bought it Harbor Freight it was cheap but it lasted for a long time I bought another one on Amazon and it didn't last but a few days I bought this one on Amazon and it's uh it's held up pretty well the only thing I had to do was I had to replace the input hose with a braided final hose so that it wouldn't collapse under the pressure on the suction rather and then of course I had a garden hose fitting on the end that's what that looks like well the last thing to do before we fill it up with oil is we need to put a new oil that are in the oil filter that's in the boat now I did replace it before I started this process but it's going to be full of that that watery oil probably got stuck in there and I'm not going to show how to do that but the filter is over on this side down in the back it's pretty easy to get to well the old doesn't look too bad but that was a sort of a sacrificial oil filter anyway I knew I was going to replace it but it looks like we did get most of the water the oil that had water mixed with it how one thing I want to mention though when I do this I typically put a oil absorbent Matt there Matt's that will absorb oil even when it's mixed with water keep that in the bilge and that way when you spill a little oil doing this when it comes off quite a bit runs down the side that Matt and the bottom picks it up before it goes out the bilge hole and keep it out of the environment I use full synthetic and all my vehicles but in particularly my vote because it's much better than regular oil and a boat runs such high rpm when I ski pole skiers and tubers that I feel it's good to have the extra protection ok the radiators back where it belongs out of the boat all the hoses are hooked up like they're supposed to be we've got the water on the ears on the out drive ready to start it up and make sure everything runs right and if there are no leaks then take it to the water for a test drive it's been running about ten minutes now wanted to make one final check to make sure the new thermostat was working according to the - gage - temperature gage it looks good last thing we want to hear that the the oil is not milky and you can just about not see the oil it's so clear so definitely is not milky it looks okay

Channel: david lindsay

Views: 80,614

Keywords: cracked block, marine engine, mercruiser, boat

Id: YfHODLqBT_E

Length: 35min 20sec (2120 seconds)

Published: Mon Sep 17 2018