Engine trouble :(

chasemixon

chasemixon

New Member
Dec 12, 2014
80
Lake Eufaula, AL
Boat Info
1990 260 CC "Twisted Pair"
look at my occupation and it will make sense.
Engines
7.4 Mercruiser w/Bravo I Drive
So, I have taken my boat out several times since I bought it in January, Deep south Alabama, had no issues what so ever.. and now on the weekend we take her up to the lake to leave it in the slip, it decides to have a meltdown... go figure right? need some advise... we have a singe 454, while the boat was running Saturday I heard the alarm sound like no oil pressure. I immediately stopped the boat checked all gauges and everything looked normal... 40 PSI oil, 185-190 water temp, it was a little high for a raw water system, but no where near 220 (red line) after about 10 seconds of idling. the alarm stopped. again all gauges looked like they had every time we took the boat out. we even took it up to lake point which is about 30 miles up the lake and back just two weekends ago... no issues. then on the way back to the slip, I hear a belt whining, then it snaps... I knew it was the alternator belt because that gauge went from 13 - 14 volts down to 11-12, we continued on to the marina at a little better than idle speed. Sunday after getting back to the marina with a new belt for the alternator, I tried to crank the boat, it had battery charger on all night, the engine just made a domp noise, never turned over... I tried several times to get the engine to turn over but nothing I did helped... my main question is, is that a starter issue or engine ceased up? :smt021 I could not turn the main flywheel on the engine by hand, but I'm not sure without any leverage that it is even possible to turn by hand.

what have I done... why me?

6-3-2015
update, I'm thinking some people didn't read the update I put later in the comments

Well, I have confirmed we have water in the oil, although when I checked the oil on the dip stick it still looked fairly clear Saturday, I was able to look at it with a friend today and take off the spark plugs... still could not turn the engine over even with the starter... friend said the starter sounded fine... and when he took off the oil cap where you add oil it was nothing but chocolate milk in there... ok, what would you guys do at this point... keep in mind, I have very limited funds, I'm almost ready to just throw in the towel on this one and part it out. maybe can get some of the money I put in it. it does have quiet a few nice things? refrig, the cushions are all covered in vinyl so they look new... but enough of my rambling. I know a reman engine would be the ideal thing, and that would be somewhere in the neighborhood of 3-4k then the cost of taking the old one out and paying someone to help me install it... what would you do? thanks in advance!
 
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Remove the spark plugs then try turning by hand. It is possible the battery got hurt. Do you have 2 batteries on your boat with a selector? If so try swapping.
 
Have you checked the oil for quantity and quality? Quality meaning that there is no sign of water or antifreeze. If the oil is discolored, the 'domp' noise you describe may be a hydrolock in one of the pistons but hopefully that is not the case. If the oil is discolored I wouldn't try turning it over again as you run the risk of doing more damage.

If the oil appears normal then try as suggested, take out the plugs to see if that allows you to turn by hand.
 
Every time I have had a broken belt some accessory has seized up. Unless the belt was really old anyway. Take the belt off and turn everything, should be obvious.
 
That "domp" noise very well could be water ingestion.
 
Bucit said:
That "domp" noise very well could be water ingestion.
Click to expand...
True, he could have water in the cylinders. But maybe whatever pulley froze to break the built is still frozen keeping the engine from cranking with the new belt installed? I am with 'blaster'. (1)Take the belt back off first and check all the pulleys. (2)Check the battery and connections. (3)Check the fluid levels and colors carefully. (4) Take out the plugs and see if she cranks.
 
Ok, so I did check the oil, I did NOT look discolored, "milky" and it was just a little above the full mark, alternator pulley turned freely, the belt was really old. I was unable to get the new one on... the water impeller pump belt was in the way, I could not find the tensioner for it to loosen. although it wasn't cooling properly it was cooling, it's a raw water system, no heat exchanger. The Water temp gauge read 190, the oil presser was between 30-40 PSI, volts were 13-14 before belt broke then 11-12 after, those are the only ones I have. I will hopefully be able to take the spark plugs out today and see if I can turn it by hand, I will update tomorrow. Thank you all for all the suggestions... It is so nice to have expert advise from you guys! THANK YOU!

If it is water lock with a piston, would you replace engine or have it machined? (fixed) new crate engine on ebay roughly $3000-4000?
 
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I had my alternator seize the last trip out last season, and snap the belt. I have the new alternator and belt ( was able to match size at Pep Boys) and am going to install as soon as I have some time. What I plan to do concerning the water pump belt, since it is extremely hard to get to the bolt to loosen the adjusting arm, I'm going to take the 4 bolts that hold the pulley on the front of the water pump off and then slip the pulley off the pump, slide the alt. belt in there and replace the pulley and reinsert bolts and tighten back up. I would take the pump off and service, but it isn't due yet. Another interesting thing I noticed is, that the alternator belt is the only belt driving the circulating water pump and alternator, which I think puts a lot of additional stress on that belt. I'm going to look and see if there is a way to get another belt on the water pump and crank pulley's to help reduce the load on the alt belt. I think that is what caused the the alt failure because of the increased tension needed to keep the belt from slipping. JMHO. Good Luck with your repair.
 
on my engine, the power steering belt is also on the water pump? along with the alternator... but I could be mistaken?
 
Yes they are both there, and that is why I'm a bit concerned that only one belt has to handle all the stress of turning that pulley with everything attached to the water pump pulley, I think my belt was slipping for awhile, because the last couple runs out last season the water temp was up just a few degrees, and that would make sense if the belt were worn and slipping then the water pump wouldn't circulate the water with as much pressure. that's why I'm looking into maybe changing one of those belts if I can to make it go around the crankshaft pulley also. It may not be possible but I'm going to try.
 
Well, I have confirmed we have water in the oil, although when I checked the oil on the dip stick it still looked fairly clear Saturday, I was able to look at it with a friend today and take off the spark plugs... still could not turn the engine over even with the starter... friend said the starter sounded fine... and when he took off the oil cap where you add oil it was nothing but chocolate milk in there... ok, what would you guys do at this point... keep in mind, I have very limited funds, I'm almost ready to just throw in the towel on this one and part it out. maybe can get some of the money I put in it. it does have quiet a few nice things? refrig, the cushions are all covered in vinyl so they look new... but enough of my rambling. I know a reman engine would be the ideal thing, and that would be somewhere in the neighborhood of 3-4k then the cost of taking the old one out and paying someone to help me install it... what would you do? thanks in advance!
 
not being able to turn it with the starter and with the sparkplugs out could indicate a seized motor. I`d look for a long block if your manifolds and risers are new. Running it with no cooling killed it
 
You mentioned that the starter sounded fine but if the motor was not turning over how do you know? I would put a socket on the crank bolt (3/4" I believe) and see if you can spin the motor over with the plugs out using a breaker bar. If not you know for sure the motor is sized or the drive input shaft seized keeping the motor from turning over (which is highly unlikely). Good luck
 
How about taking the spark plugs out and if it'll turn over do a compression test. Could just be a blown head gasket.
 
boatrboy said:
You mentioned that the starter sounded fine but if the motor was not turning over how do you know? I would put a socket on the crank bolt (3/4" I believe) and see if you can spin the motor over with the plugs out using a breaker bar. If not you know for sure the motor is sized or the drive input shaft seized keeping the motor from turning over (which is highly unlikely). Good luck
Click to expand...

You never even want to do that, break the nose bolt and your really screwd
 
Bt Doctur said:
You never even want to do that, break the nose bolt and your really screwd
Click to expand...
Good point - I will add to my post "not exerting enough force to snap a 1/2" bolt". :) My point is if the motor spins freely it's not seized and he may have options before throwing in the towel.
 
Get a marine mechanic to look at it. Not much point trying to guess and its important not to leave the water in the block in case its not a failed block. The longer you leave water in the oil the more possibility of more internal damage from rusting inside the cylinders and on the crankshaft and valve system. Let a pro take a look and then you can decide.
 
First thing I'd do is change the oil, several times, get inexpensive oil and filters and change it, run for a few minutes at idle, change, until no more 'milkshake'. That will preserve the engine and internals while you figure what to do. As others have said, get a mechanic to look at it.
JMO, but I think that you may have overheated the engine after the belt broke, possibly warping/cracking a head or blowing a head gasket. That allowed coolant into the cylinder(s). If you are in fresh water, you are better off than if you were in ocean water, so you may be able to salvage that engine with a head or gaskets and a through flush out of the crankcase. Again, have a mechanic look at it.
Good luck and let us know what you find.
 
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