View Full Version : Cracked block or something else?

11-20-2009, 09:01 PM
I have an Indmar 351 in my 91 ski boat and this summer, when the motor is running, noted small drops of water running down the face of the lower cover of the bellhousing on the port side of the engine and creating a small puddle of water under the motor in the bilge. The water originates from somewhere on the rear port side of the engine hidden inside of the bellhousing. It leaks very slowly...perhaps a droplet the size of a pencil eraser every 30 to 60 seconds. I havent been able to find a diagram of the rear of the motor but I dont believe there are any frost plugs there. I believe there is an oil gallery plug on each side and the camshaft bearing seal in the middle...these plugs look like frost plugs but aren't. I monitored the engine this past summer and checked the oil before and after each trip....I found no water in the oil at all and ended up running up about 35 hours on the boat. There does not seem to be any overheating issue either? Before I purchased the boat the tournament boat shop I had look at it noted that the heater and exhaust manifolds had frozen but that the trans cooler was ok. I repaired the heater and replaced the manifolds and all was well. This past winter....my fault...an unexpected cold and a poor winterizing job on my part saw the two rearmost frost plugs pop. I cleaned these up and re-installed them prior to noting the drip I discuss above. I cant say for sure if the drip was present since I purchased the boat or if it started this year? It is such a small amount of water that one could easily miss it if it wasnt being watched carefully. Any suggestions would be appreciated.

11-20-2009, 10:41 PM
I can't be specific on this at all, but I do remember the guys on here saying that the MCs do drip water and that it is normal. Even my boat when I bought it, Danny told me that if I'm ever peaking around and seeing water dripping every so often, that it's normal and not to freak out. Don't remember it being on the backside of the engine, thought it was the port side and not the starboard side though, which would be the around the same locaton your describing, this model year starts at '94, but here's an operators manual read in .pdf format, maybe it might be of some help


11-20-2009, 10:46 PM
Teal never heard this....sure the guy was not referring to the shaft packing?

11-20-2009, 11:21 PM
W T H.......................................:rolleyes:

11-21-2009, 06:22 AM
Hmm..my boat does'nt drip water. Seems like the only reason it would drip was if something was loose or broken..

11-21-2009, 11:08 AM
I'm fearing broken however it doesnt drip much so the break must be tiny. 35 hours with no issues has me thinking I'll give it a go again next year as is.

11-23-2009, 12:14 PM
I wouldn't run it a year knowing it leaked, but I guess if it doesn't get worse...oh well.
Thought there was freeze plugs on the back og the block too, but it's been a while.

11-23-2009, 02:28 PM
If you remove the transmission and bellhousing, you should be able to see where the leak is from. it should leave a nice little tell-tale trail.
If I remember correctly, there may be some core plugs back there. But, it really does not matter - the trans, flywheel and housing need to come off to find the leak.

11-28-2009, 12:24 AM
only place water should be dripping, and even then, only a little, would be the shaft packing to the rear of the transmission. wouldn't think there should be any water around the bell housing unless you had a lot of water in the bilge and it was splashing up in there. saw our 87 when it was apart and the flywheel/dampner plate didnt have any water of sings of water ever being dripped or leaking there. i'll be curious to see what you find out when you take it apart.:confused:

11-28-2009, 12:59 PM
Teal never heard this....sure the guy was not referring to the shaft packing?

Coulda been... duno, never seen water leakage. I'm too busy big pimpin' in my big bad mastercraft to give a damn:D LMAO, geeze I crack myself up

12-17-2009, 08:19 AM
Your motor shouldn't leak any water. If it is coming from inside your bellhousing, you probably have a freeze plug issue. You will need to remove your tranny and bellhousing to see your problem, but there is a freeze plug in the area that you are describing.

01-11-2010, 10:45 PM
Does anyone know FOR SURE whether or not there are any freeze plugs located on the back, flywheel end, of an Indmar 351 Ford Windsor? I know that there is a camshaft plug and two oil gallery plugs that look just like freeze plugs but I dont believe there are any freeze plugs on a Ford 351W.

01-12-2010, 12:05 PM
I did a quick search, for you, and found these pictures. I hope that it helps. My boat is Chevy powered so, I haven't any first hand advice. Rick


01-16-2010, 12:45 PM
I cant access that page for some reason?

01-16-2010, 01:48 PM
Possibly a freeze plug leak on the back side of the head. Guess what they did there job. Or possibly a cracked head or blown head gasket. Not the end of the world at all

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