Coolant where it shouldn't be

Jun 7, 2016
315
Catalina C30 Warwick, RI
I posted this on CF last night but wanted to post it here also, as the knowledge base here may be a little more specific to the problem, so I apologize if you're on both forums and are seeing this twice.

I am in the middle of doing a meidum sized "refit / reno" on my new to me boat this winter. During one of my projects after I removed the engine, I then removed the exhaust manifold/coolant manifold reservoir.

There are only 6 studs that hold it on and when removing one of the studs there was a signifcant amount of coolant that came out one of the stud holes in the manifold (see manifold picture, it was one of the circled holes though I can't remember exactly which one)

Looking at it more today, I realized there is no way that I can see that coolant should ever have made it in to the stud hole. (if you see the picture of the inside of the manifold there is a passage way for each stud that should be sealed off from the coolant.

Normally I am of the mindset that, when in doubt replace it, but......... however a new manifold from westerbeke/universal is $1500.
Although if need be I will go down this route I am praying there may be another solution as there are a lot of other things on this boat that $1500 will be very useful towards.

Does anyone know if there is a work around for this i.e. since there is not a lot of pressure in the system, can I just seal off each side of the stud holes when installing it and be good or do I just need to bite the bullet and watch my refit budget keep creeping up?
Inkedmanifold_LI.jpg
Inkedmanifold 2_LI.jpg
 
Feb 8, 2014
1,300
Columbia 36 Muskegon
The problem is not in the manifold, it's in the cylinder head. Actually it's not a problem, it's a minor design flaw. The bottom stud holes on #2 and 3 cylinders actually penetrate the water jacket in the head. All Kubota 3 cylinder 70 series engines will do this. When you put the studs back in, coat the head ends of those two studs with Loctite and they shouldn't leak.
 
Feb 8, 2014
1,300
Columbia 36 Muskegon
Looking at the picture again, you've got the top holes circled. The coolant should have come out two of the bottom holes, so there could be a problem with the manifold if you're sure where the fluid came out. But I doubt it. If you pour coolant into the engine through the thermostat, you should see it come out the aft two bottom stud holes. If you do end up needing a manifold, check out ASAP Supplies in the UK. They sell the Thermex "manicoolers" (water cooled manifold with built in heat exchanger) that Beta puts on their marine engines. Assuming yours is an M25 series you want the one for the Kubota D850. Cost is around $500 shipped to the US. They also have the PRM 60D transmission which is a drop in replacement way better than the Hurth. Also around $500 US. The Hurth is a piece of crap, you will eventually have problems with it.
 
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Jun 7, 2016
315
Catalina C30 Warwick, RI
Looking at the picture again, you've got the top holes circled. The coolant should have come out two of the bottom holes, so there could be a problem with the manifold if you're sure where the fluid came out. But I doubt it. If you pour coolant into the engine through the thermostat, you should see it come out the aft two bottom stud holes. If you do end up needing a manifold, check out ASAP Supplies in the UK. They sell the Thermex "manicoolers" (water cooled manifold with built in heat exchanger) that Beta puts on their marine engines. Assuming yours is an M25 series you want the one for the Kubota D850. Cost is around $500 shipped to the US. They also have the PRM 60D transmission which is a drop in replacement way better than the Hurth. Also around $500 US. The Hurth is a piece of crap, you will eventually have problems with it.
Thank you, that is great info. To be honest I could be wrong about which hole it came out of and it very well may have been the bottom hole. There were 3 of us removing the engine that day and I was more worried about how to get the engine out of the boat than disconnecting everything. (I'm the crazy one that strapped a cherry picker to a pick up truck as a engine hoist Removing Engine while on the Hard)
 
Jun 11, 2004
1,621
Oday 31 Redondo Beach
I freaked out a bit when coolant came out when removing a stud on my M-18 for the alternator bracket upgrade. Turned out it was normal and I should have drained the coolant first. Ended up not to be a problem.
 
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Feb 26, 2004
22,760
Catalina 34 224 Maple Bay, BC, Canada
I freaked out a bit when coolant came out when removing a stud on my M-18 for the alternator bracket upgrade. Turned out it was normal and I should have drained the coolant first. Ended up not to be a problem.
That's exactly what I suggested you look up on marinehowto over on CF: the alternator bracket upgrade, sorry I forgot the specific subject over there.
 
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Feb 8, 2014
1,300
Columbia 36 Muskegon
That's where I saw it too. When I saw coolant dribbling out of the holes I thought I had a cracked block. I had just bought the engine used and thought I'd gotten screwed. Then I read MS's article and saw what it really was. Later saw the same thing on a tractor forum. Whew!
 
Jun 7, 2016
315
Catalina C30 Warwick, RI
That's exactly what I suggested you look up on marinehowto over on CF: the alternator bracket upgrade, sorry I forgot the specific subject over there.
That's where I saw it too. When I saw coolant dribbling out of the holes I thought I had a cracked block. I had just bought the engine used and thought I'd gotten screwed. Then I read MS's article and saw what it really was. Later saw the same thing on a tractor forum. Whew!
Thanks to both of you:thumbup: That's definitely a relief!