Cracked Manifolds!

rockhouse

New Member
Feb 12, 2010
8
TX
Boat Info
1991
Engines
4.3 L
Hi all, first post.
I've got a 91 Sea Ray 200 with a 4.3 Mercruiser. I just slapped the water muffs on it to fire it up and noticed water dripping from the manifolds. I felt with my finger and there is indeed cracks at the bottom of both manifolds, on the bottom but above the bolts.
I'm sure it was caused by a hard freeze recently. So my question is...what do i do now?
There is no water in the oil, but other than that i don't know what to do. Is there something else i should check to make sure the block is fine? If it's just the manifolds, how much will two of them cost, and how labor intensive is it if i do it myself?
Any info is appreciated...and i hope this in the right sub-forum.
 
Hi all, first post.
I've got a 91 Sea Ray 200 with a 4.3 Mercruiser. I just slapped the water muffs on it to fire it up and noticed water dripping from the manifolds. I felt with my finger and there is indeed cracks at the bottom of both manifolds, on the bottom but above the bolts.
I'm sure it was caused by a hard freeze recently. So my question is...what do i do now?
There is no water in the oil, but other than that i don't know what to do. Is there something else i should check to make sure the block is fine? If it's just the manifolds, how much will two of them cost, and how labor intensive is it if i do it myself?
Any info is appreciated...and i hope this in the right sub-forum.

On a previous boat with twin 4.3 Mercruisers, I had the same problem because the person who winterized the engines did not run them long enough to bring the temperature up to open the thermostats before running the glycol through the muffs. I had the manifold cracks welded and that did the trick. Let's hope that your blocks are not cracked. :thumbsup::thumbsup:
 
On a previous boat with twin 4.3 Mercruisers, I had the same problem because the person who winterized the engines did not run them long enough to bring the temperature up to open the thermostats before running the glycol through the muffs. I had the manifold cracks welded and that did the trick. Let's hope that your blocks are not cracked. :thumbsup::thumbsup:

Thanks for the response.
How would i know if the block is cracked? The boat starts fine, runs fine, and there is no water in the oil. The only apparent problem is the water leaks in the manifolds.
Is there something else i could check?
Thanks.
 
Thanks for the response.
How would i know if the block is cracked? The boat starts fine, runs fine, and there is no water in the oil. The only apparent problem is the water leaks in the manifolds.
Is there something else i could check?
Thanks.

Well, water in the oil is a definite no-no. If you don't want to pull the heads to inspect, then it is a crap shoot. You can spend the money on welding your cracked manifolds or replace the damaged ones with new or used exhaust mainfolds and keep your fingers crossed that the block(s) are not cracked. I paid $125.00 per manifold for the welding and got lucky.
 
Also, does anyone have a link or part number to the manifolds i need? It's a 1991 Sea Ray 200 with a 4.3 L V6 Alpha one stern drive....thanks.
 
Well, water in the oil is a definite no-no. If you don't want to pull the heads to inspect, then it is a crap shoot. You can spend the money on welding your cracked manifolds or replace the damaged ones with new or used exhaust mainfolds and keep your fingers crossed that the block(s) are not cracked. I paid $125.00 per manifold for the welding and got lucky.

So the only other option is pulling the heads and looking at the cylinders?........crap.
Do you know how much new manifolds run?
 
When i was going to fire it up i checked the oil first. It hadn't been checked since mid-last summer. The oil was a little low and black (dirty). There was NO water anywhere on the stick after 3 pulls on it. I added a half a quart, checked it, it was full, then i turned on the waterhose for the muffs and fired it up. It took a few cranks to fire cause it was so cold. After that it ran fine but the manifolds leaked. I checked the oil after finding the leaks and it still had no water in it. After taking the water lines loose again to drain them, the water was clear with no oil.
Is there ANYTHING that will tell me whether or not it's JUST the manifolds, without pulling the heads?
Thanks for any info guys.
 
When i was going to fire it up i checked the oil first. It hadn't been checked since mid-last summer. The oil was a little low and black (dirty). There was NO water anywhere on the stick after 3 pulls on it. I added a half a quart, checked it, it was full, then i turned on the waterhose for the muffs and fired it up. It took a few cranks to fire cause it was so cold. After that it ran fine but the manifolds leaked. I checked the oil after finding the leaks and it still had no water in it. After taking the water lines loose again to drain them, the water was clear with no oil.
Is there ANYTHING that will tell me whether or not it's JUST the manifolds, without pulling the heads?
Thanks for any info guys.

This situation is much like electricity in that the path of least reisitance will be taken by the water. Once the manifolds are either welded or replaced, the water will either go where it is supposed to go or it will be forced through cracks in the block if they are indeed present. I'm sorry Dude ... I really don't think that there is any "easy button" for this one. It's your call to roll the dice or not. It is a $xxx.00 welding decision + gasgets. That is all that I have to say on this subject. Good luck and keep us informed. :thumbsup::thumbsup:
 
If the leaks from the manifolds aren't that bad I would run it on a hose for 20 min. to let it get up to temp then shut it down and check oil. Also which manifolds do you have the 1 piece or two piece. I don't think they make the one piece anymore.
 
Unfortunately, I've been where you are now last year. I bought a 1994 185 BR from a good friend of mine and it was our first boat. He told me at the end of the season to make sure I get it "winterized". I did stop at a local shop a couple of times to make an appointment with no luck. As it was our first boat, I really didn't understand at the time what winterizing involved and how important it was to have done. Unfortunately I didn't follow through with it and didn't get it winterized. Come about March, my friend that I bought the boat from asked again if I had gotten the boat winterized and when I told him no, he said that I'd probably had done some real damage to the engine in not getting it done.

At the first opportunity I put the water muffs on, fired her up (started with no issues) and at first I thought all was well, but after a couple of minutes, I noticed water pouring out of the engine where it shouldn't have been. I shut her down, took a look at the manifolds and I could see on the left side a major crack. I took it down to the nearest Marine Max for a estimate on how much damage had been done. You could've knocked me over with a feather when they said that the total cost would be around $7,000, which would be replacing both manifolds and the block as it had cracked as well. I only paid $6,700 for the boat and trailer to begin with...

So here I was with a boat that would cost me more to repair than I had paid for. The admiral (not initially a big supporter of buying the boat in the first place) was open to the idea of looking at a larger boat, so I gave the boat and trailer to one of my wife's nephews as a project boat, and we went down to the nearest Sea Ray dealer, where we found a very very nice 2006 240SD, which we are now the proud owners of. I can tell you that at the end of this last season that I had her completely serviced, winterized and shrink wrapped.

I was completely naive about boat ownership with the first boat and learned probably one of the most expensive lessons ever, but the lesson was well learned.

I don't have any advice as to whether or not your block is cracked, as the service dept. at Marine Max had to tear it apart to determine the full extent of the damage. Just be prepared for what it might actually cost to get it all repaired.
 
This may be a good time to start a search on craiglist for a good used engine or a parts boat with a good engine.Put an ad in the boat for sale section ,i got some great deals there such as used top bows for my camper for 80.00.and 2 electric downriggers with swivel basses clips and balls for 125.00.
 
rockhouse: As far as your suspect cracked block goes, don't start ripping the heads off just yet. The coolant regulated side of the system should be able to be isolated and pressure tested. When a block cracks from freezing it's typically a big enough hole to where the system wont hold up to a pressure test at all.

If you think you can handle testing yourself, then school/tool up with a service manual and pressure testing tooling.
...Ron
 
First off, I'd send out an oil sample for analysis. While they're out, pull the manifolds and examine them. Do a compression check and/or leakdown test to see if there are any leaks in the cylinder walls. All pretty easy stuff. Welding cast iron is tricky business and for maybe an extra $50 per, you can buy new OEM ones. Best prices are B0ATFIX.com Not sure if they make the ceramic coated for the 4.3 but if they do, you want thosey if you're in salt water and are not fresh water cooled.

This is probably your part but check it to be sure...
2209_reg.jpg


Merc part #99746A17
 
Last edited:
First off, I'd send out an oil sample for analysis. While they're out, pull the manifolds and examine them. Do a compression check and/or leak down test to see if there are any leaks in the cylinder walls. All pretty easy stuff. Welding cast iron is tricky business and for maybe an extra $50 per, you can buy new OEM ones. Best prices are B0ATFIX.com Not sure if they make the ceramic coated for the 4.3 but if they do, you want those if you're in salt water and are not fresh water cooled.

This is probably your part but check it to be sure...
2209_reg.jpg


Merc part #99746A17

You're right Ron. One way or another, they have to come off. New OEM ones + new gasgets are the safest way to go. You need to have an experienced cast iron welder or you may be pulling them off again because of a minute leak that does not show up to the naked eye. It's a shame that this happened, but sometimes you just have to bite the proverbial bullet and not take any short cuts. Good luck with this and keep us posted. :thumbsup::thumbsup:
 
Pulling the manns is a good idea. You already know there bad. I would hold off on spending any $ yet till you get a look at the whole picture.

If you haven’t run your eng long enough to contaminate the oil then an oil sample wont tell you much.

Taking a compression test is will tell you if a cyl is not holding yes, but it wont be conclusive if the block is opened up at some other point.

A block will crack at the water jacket area: externally by freeze plugs, internally by lifter gallery or internally at a cylinder.

IMHO: pressure test, if it holds pressure great. If not; pull the firing pins out, hit the starter, if water comes out any of the holes there's a problem area. If no water out any of cyls, pull intake and visually look far water trails.

FWIW: there is a procedure called "iron stitch" Detroit Diesel recommended this back in the day for cyl head repair in a combustion area of cyl heads. From what I've seen it didn't work too well in a combustion area. It does work well on cracked castings in low pressure areas. ... Another procedure recommended by Cat is "Belzona". Its a ceramic epoxy. I have successful repaired a half a dozen or so 28 liter V-12 blocks subject to corrosion in the lifter gallery area over the past 20 yrs.

No body's saying here you have big problems yet. Just you need to test instead of guess.

...Ron
 
Thanks alot guys, i appreciate it.
I'm gonna hook the waterhose back up and let her run to normal temp. then check the oil, and the water, for contamination. Then i'll yank the manifolds and take it from there.

Just outta curiosity, what do yall think a '91 sea ray in good condition would go for as is, with cracked manifolds?
Or how much could i get for the boat if the block's also cracked?
At this point i'm weighing the cost of parts, and my time (which is scarce), versus just letting the boat go for as much as i can get...(which i'm sure isn't much).
 
Is there water coming out the bottom of each in equal amounts?
Have you actually seen the cracks?
If not, could it be that the blue plugs have been removed for winterization?
 
If you decide to sell "as is," check out yachtworld and find some sisterships and look at the asking price. Then figure on approximately a $2-3K (?) discount if the engine has to be blocked out (Parts and labor). You could also go the "donate" route for the tax deduction, whichever net's more in your pocket.

Is yours a 200 weekender? Couple on yachtworld in the States in the $8K-9K price range.
 
rockhouse: Doesn’t sound like you have the time for the DIY stuff.

Not knowing what tools you have laying about: Since your gona run it again. Perhaps if you put the muffs on and get water flowing with eng off. Pinch off the hoses going to the manns (close to stat housing), this should stop the water flow out the stern. The spring pressure of the muffs should keeps the system pressure low. Let it set this way for a while. ... Check the oil to see if it's coming up or has signs of contamination. Un pinch the lines to return water flow out the stern, try to start it. If it doesn’t hydro lock and the oil looks good, then re eval your options.

And yes, make sure those drain plugs aren't what your seeing.

my .02: you just have a manifold issue and nothing more

...Ron
 

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