Mercruiser Woes-What Next?
 

Since we like to share our triumphs as well as tragedies here on CSC-here's a crappy story:

Well, my years of trouble free performance and never getting towed in have come to an end this fall.
My 5.7 stalled at idle the other day while I was crushing the bass on jigs. Hmmm-that's funny this motor never stalls. Start it up again-same thing a few minutes later. Try again to start-no sir, just a spinning starter.
You guessed it(maybe)-I ingested saltwater through a failed exhaust manifold. Turned it over by hand to get the water out of the cylinders on that side. Fogged those cylinders. The next day I discover that the water leaked down into the oil, so I pulled that all out and pickled the motor with diesel because I'm going to mom's house for the holiday.

So here's where I'm at:
The motor is a 99 and doesn't owe me anything, but saltwater ingestion just can't be good.
Do I
a.) Try to save it and hope the internals are good and ride around nervous for the next few years.
b) Go for a rebuild
c.)Drop in a new motor and be done with it.

Don't tell me to bracket it and put on an outboard 'cause I aint go the coin for that ; )

Anyway, any of you motorheads out there feel free to give me advice or moral support.
And, to all, Happy Thanksgiving!
Doug

Re: Mercruiser Woes-What Next?
 

Just went through the same thing...we chose to rebuild it ourselves (I have a few experts in the family :-)) on a 4cyl inline it cost us $600 in parts, $200 in machine work...labor...free...sort of :-). I'm glad we did it this way, it always costs more than you expect...because we lapped the head, replaced the valves and seats, bought new manifold and exhaust riser...bla, bla, bla...

Re: Mercruiser Woes-What Next?
 

From everyone I talked to, manifolds primarily used in salt water last 6 years tops, anything beyond that you are on borrowed time. My dad has the same package, 2000 mercruiser with a bravo one. He had the usual fuel pump issues early on, but has over 3000 hours with no major issues and it runs great. His manifolds went at 6 years and he flushes with fresh water after every trip. I would put new manifolds and run it until it starts giving you major problems. When the time comes, and you decide you don't trust it, then go new...outdrive and engine. I like mercruiser and Volvo. I would not go near the composite drive butt the new sea core othat looks like my dph drive is really cool.

Re: Mercruiser Woes-What Next?
 

If it's a raw water cooled engine, I'd check the cross-over passage in the front of the intake manifold (where the thermostat is) too. Your engine is old enough that the exhaust manifolds may have already been replaced, but salt water in that intake manifold passage could still get you. I've seen it happen on older engines!

Re: Mercruiser Woes-What Next?
 

I tend to agree with the other posts. From experience and from all the old salts here in FL. Manifolds will last six years. Cheap insurance to change after 6 years. 90% of engine failure comes from the manifolds.

If it were mine and $ were a concern here is what I would do. Replace the manifolds and run it to see what gives. If if checks out your good to go. If not then go buy a short or long block take all the stuff off your old block and put it back in the water. In 5 years change the manifolds and keep on going.

Keep us posted on what happens.

Re: Mercruiser Woes-What Next?
 

The block is fwc-what they call a 1/2 closed system. I guess what I'm wondering now is which route to go and whether I need to tear down the motor-or at least the side that failed. I was definitely on borrowed time with the exhaust. It's just funny that it failed right after some other repairs that I had done.
I really am handy, but I think tearing open the block is way beyond my skill set.
So I 'm sitting here flushing this motor out, wondering about my next move. If I want to run this motor again, it is going to require new manifold and riser for at least one side just to discover whether my 11 year old motor is worth salvaging.
Ahhh????

Re: Mercruiser Woes-What Next?
 

It sounds like you need new exhaust manifolds anyway, even if you buy a new long block, so I wouldn't sweat that! A compression test will tell you if you have any sticking valves or rings without even running it, so I'd do that first, before even buying new manifolds. If a cylinder is down in compression, squirt some oil in that cylinder and test again. If compression comes up it's a stuck ring or scored cylinder, indicating major overhaul required (or new short block!). If compression doesn't improve with oil in cylinder, it's a sticking or leaky valve or possibly a blown head gasket, especially if 2 adjacent cylinders are low. Requires pulling heads and having a valve job done.

If you got water in the oil, best thing to do is change the oil & filter and get it running asap and get it up to temperature for awhile to evaporate any remaining moisture. I would be a little concerned about rust on the cam if the engine got a lot of water in it, as the Chevy's use pretty small diameter lifters so there is a lot of stress on the cam lobe/lifter surfaces. If there is much distress there, the cam lobe will wear off pretty quick. If you can run the engine for a bit with fresh oil in it, get an oil analysis kit, which includes a syringe and tubing to pull an ounce or two of oil from dipstick tube, and have it checked for high levels of wear metals. This is a routine check on all aircraft engines. If wear levels are low, you're good to go. If levels are high, then you'll have to make a decision on how much work/time you want to invest on a rebuild or spend more $/less time on a new or rebuilt short or long block.

If you have a factory service manual, and decent mechanical skills, teardown and rebuild of a 1950's technology OHV auto engine really isn't that difficult, especially if it only involves pulling the heads or changing a cam & lifters. Could do either of those jobs with engine in boat. Toughest part of the job is probably pulling the rusted exhaust manifold bolts/studs! A read thru the service manual will give you a good feel for what's involved. Hope this input helps. Denny

Re: Mercruiser Woes-What Next?
 

Don't sweat it, change the oil, replace the manifolds and get it running ASAP. The important thing is you need to run the engine very soon and get rid of the moisture. At the bare minimum (as of right now) I would change the oil, remove the water supply hoses going to the manifolds, hook up the muffs, and start the engine letting the coolant water run into the bilge until the manifolds start to get hot, then shut it down before you melt the big exhaust hoses. Do this for now until you get your new manifolds installed. Then once your new manifolds are on, take the boat out and run it easy for the first hour or so. Take your oil cap off and look for moisture, milky oil, etc. If none is present, then your good to go. :cool:

Re: Mercruiser Woes-What Next?
 

SH*T !

I have the same motor, 2001, 350 300hp Mag MPI ( fresh water cooled. With original elbows, manifolds and risers... 450 hours. Salt water use... I never flush after each use.

I have a few questions - obviously my manifolds are older than (6) years.

(3) years ago I had my mechanic replace the gaskets at the risers joint - he said the manifolds from that point looked great...

My motor runs cool as she ever has - Should I replace the manifolds, elbows and risers if all seems OK ?


BTW - If I were in your predicament, not being as mech inclined as many of the above - I would do a few oil changes w/ marvel mystery oil in there. Run and dump oil. Get moisture out. Compression test to make sure is OK, 'pickle it' fuel side and oil. Then get new manifolds and install - start her up ASAP, run for a awhile, then winterize again...

Good luck...

Another LI'er...

Re: Mercruiser Woes-What Next?
 

I'm all over it and praying while I'm at it.
Dude-my boat never ever came close to overheating. they were clogged-they failed-manifolds.
All of the guys on boatered preach changing them as routine maintenance-do yourself a favor and do it now-this is a freakin' nightmare-especially while the bass are chewing hard on herring out east and in mtk-my favorite time of year. I had no warnings.
You can get a pretty good deal on the whole kit locally. Shoot me a pm if you need it.
Don't wait-it totally sucks. i'm just glad it happened in a pretty benign place and not out in some big rip.
BTW-I can help you do the swap-it's not hard at all and worth saving the coin and doing yourself.

Re: Mercruiser Woes-What Next?
 

I pulled my boat a week or so ago as I always do before opening day of deer season. Weirdest bass season I can remember. The bass here on the southshore never entered the Great South Bay - they all have been in the ocean, caught on jigs. A lot of schoolies. I'm a live bait guy and target bigger fish, so I thought, "well, this season sucked"... But, I do hear it's still on !

Anyway, sorry to hear about your engine, and you're right, it could have been out in a bad place, snotty seas, COLD! etc.

Damn! I'm all about preventive maintenance and I know the job should be done, but it's a tough one to do when all seems perfect ! Your story, however has me freaked out !

Where did you buy your manifolds and set-up and what did it set you back ?

How was the labor, any tricks / shortcuts I should watch for ? How long of labor for each side ? I have done a lot of peripheral mechanical stuff on this engine; fuel injection cooler ( BITCH of a job ), new water ciculator/pump, exhaust bellows, heat exchanger, etc. plus all the seasonal maintenance.

My motor is very clean and well cared for - better than a mechanic would do - I guess anyone on this site has to be fairly meticulous or they would let other people work on or repair their boats... But, a 'clean' looking engine does not tell the inside story...

What'cha think ?

Re: Mercruiser Woes-What Next?
 

If you asked me a week ago, I'd say wait em out, but my manifold failed internally with no signs of decreased performance/overheating. If I could do it again, I would be pro-active. i think you're on borrowed time. If you post the question over on boater ed forums you will basically get shouted at that you are about 3 years overdue.
You certainly can roll the dice, but it's been a crappy end to my season. Good thing I like fishing the surf.
By the way, my buddy had nice fish the last few days in FI inlet on spot and herring-up to 30 lbs.
I got the exhaust from lighthouse in r-head-they go by partman online. Very cool guys and a big operation. All of my research on aftermarket led me to the oscos, which come with all the mounting hardware and the gaskets. Merc is making a low end product now, as well.
You could def. handle the job, but an extra set of hands would surely help. Manifolds are heavy beasts.
If you have any other questions, let me know. I'm hoping I dodged a bullet here.
Maybe we can hook up and do a N.Shore/S.Shore thing in the spring. The fluke bite gets pretty fiery just outside of my homeport in june.
Doug

Re: Mercruiser Woes-What Next?
 

if you're smart,you're gonna replace the engine with a complete new engine-too many horror stories !
it's gonna cost more,but,in my opinion(i own a marine repair shop) it's the best option-it's also the only way i repair problems like this.
using a "long block" that's reman'd is a crap shoot at best.

manifolds and risers-5yrs max-flushing has no bearing here.overheating isn't a factor either-the water passages will erode away,allowing the water to enter the cylinders via the exhaust valves-eroding the valves and causing a low,or,no cmpression situaton.remember,we're talking about sea water-this is where the cooling water is expelled.sea water in an engine isn't a good thing-think about the dissimilar metals here...
if you're engine "locked up" due to hydro locking-you would've had a few tell tale signs to alert you to a potential poblem-"steam" from the crankcase vents- breather tube,where it goes to the flame arrester,salt residue may be present as well.you may have noticed a drop in max rpm too...
getting into the habit of a yearly compression test is usefull-it gives you the opportunty to inspect the plugs-look for plugs with either a rust stain,or,plugs that are snow white-steam cleaned-this is another tell tale-this shows there's water entering the cylinders...

trust me,the advice i gave is the best...

Re: Mercruiser Woes-What Next?
 

Fishing - heard about the spot but $5 a pc a is stiff. Not much bunker this year - a weird run... Maybe next year will hook-up with fishing... I never fish the north shore...

As for manifolds - did a little reading tonight. Mercruiser makes the ceramic coated manifolds - pricey ! I wonder if it matters which you use - OEM or aftermarket.

Pelican - you have an opinion here ?

Old - did you R/R elbows too ?

Also, did you torque them down or just tighten by estimate ?

Re: Mercruiser Woes-What Next?
 

I agree with everything here but the issue of flushing. Flushing your engine can save your from early failure, but failure will still come. Regular motor flushing can extend manifold life to 7 years IF it is done without the motor ever cooling with salt water still in the manifolds.
the problem is many/most people shut the motor down while drifting or anchored, or fail to flush after use until they trailer the boat home, allowing the motor to cool and then reheat with high quantities of sodium still in the manifold.

Replace the motor if you plan on keeping the boat for more than two more years. Replace the motor with a closed cooling system and heat exchanger, and STILL change the manifolds and risers every 5-7 years.

Re: Mercruiser Woes-What Next?
 

Frank, read his first post carefully. :D He has the partial closed cooling system which means that his engine/block is fresh water cooled only however the manifolds/risers are not. That being said I would see what I had before I just spent a lot of $$$ on a new engine. What normally kills a inboard or I/O is most of them are completely raw water cooled and the salt eats up the block/heads etc. Another option would be to get a new long block from GM and install his marine cam and acc. from his other engine, being a 1999 it should be a roller cam, which is nothing wrong with re-using provided it looks good.

Re: Mercruiser Woes-What Next?
 

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in 20yrs,i've never seen an engine fail directly due to being raw water cooled

i've never seen an engine fail due to lack of flushing either...most engines fail due to exhaust manifolds an risers leaking.i've seen the engine block break-where the starter mounts-the hi torque starters will actually shear this area off,when the motor hydro locks...
i've seen many boat owners with the exact same prolem,some opted for the "reman long block"-when all was said and done,the money spent was almost the same as a new complete engine...just some good advice...

Re: Mercruiser Woes-What Next?
 

Mercruiser makes the ceramic coated manifolds - pricey ! I wonder if it matters which you use - OEM or aftermarket.

Pelican - you have an opinion here ?

What should a set of manifolds and elbows cost for a 2001 350 MAG MPI - fresh water cooled ?

Re: Mercruiser Woes-What Next?
 

not sure if the administrator here would appriciate me giving prices-it could be tuned into me soliciting biz...

i use "OEM" parts only-if it's a merc,it gets merc parts-same for volvo's-ect...

truth is,the exhaust system is the weak link-this is usually where problems begin.alot of owners cause their own problems.improper storage is one cause of problems-storing an engine"dry" is one thing that's common.when stored-an engine should be "fogged" and ran on non-toxic antifreeze.reason being,if the cooling passages are "wet",there's an absense of air-meaning,no oxidation-get what i'm saying ?
flushing-you can flush all you want,but,truth is,the exhaust system still has a usefull life of approx 5 years-raw water side.read that as,if the exhaust system is raw water.in a fresh water cooled exhaust system,the risers are the point of raw water expolsion-these are good for 5 yrs max-the manifolds will last longer-only problem comes in,at the riser gasket/block off plate-this point will fail.merc has a "dry joint" here...

if i were you,i would compression test the engine,then winterize it,then replace the exhaust system.during winterization,i preform,and recomend others to perform a compression test,at this time-it will alert you to potential problems in the engine.do not go by the old "water in the oil",when water shows in the oil,the damage has allready been done.an example of this is,rust on valve springs-if rust is present,the spring is gonna fail.this is why,when an engine has water in the oil-and it locked up,attempting to free it with pour in products is like peeing on a forest fire-the damage is done...

i have the same power in my sea craft-2002 5.7 mpi merc,with the horizon package-the boat was in storage for 3 seasons-this year,it's getting a new exhaust system...it's all about preventitive maintance-i practice what i preach,avoid a problem before it happens...

Re: Mercruiser Woes-What Next?
 

[QUOTE]
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Well if he had shut the engine down and stored it for the winter not knowing that he had a problem, then it would cause major problems with the cylinder sitting with water in it all winter long which in turn would probably warrant engine replacement. However this doesn't sound like the case, he has found the problem right when it happened which should pretty much be treated as if the boat had sunk (pickling, oil change water removal etc.) If the boat had sunk you wouldn't just automatically assume that the engine was bad and just replace it, you would get the water out and get it running. I'm not a parts changer, I like to be sure that the part that I'm changing is actually bad, just throwing parts at something is the easy thing to do and requires no skill. If you wrecked your truck and it was fixable you wouldn't just throw it away and buy a new one you would fix it. As far as corrosion goes, on a completely raw water-cooled engine, the engine is made from the same materials as the manifolds, which is cast iron. The manifolds go first due to heat and they are thinner than the block, then the heads will go next. Usually the water passages get ate up and are so large that the head gasket will no longer seal it. Ask me how I know this? :D My father use to own a Marina and use to work on boats. I have been turning wrenches with him since I was 10YRS old; I'm now 40. The last thing that he want's to do is winterize it with moisture still present, if that happens, then he most likely will need an engine replacement.

Re: Mercruiser Woes-What Next?
 

this gentleman "alb" asked for an opinion on his engine- i gave it to him...he made no claim of moisture in the engine-read what i typed-good advice...
the advice i gave to the gentleman with the locked up engine stands...
i'm no parts changer,as you implied.
i gave very usefull good advice.
20yrs in the biz,i've yet to see an engine fail due to it being raw water cooled,sorry...
as for engines being submerged,the engine needs to be ran as soon as possible-and ran under load,to remove the moisture.problem comes in,when dealing wth fuel injected engines-usually,these will require replacement of components-ECM's,low pressure,or "lift" pumps will require replacement,along with the standard electrical parts-which usually ends up,the cost of a true repair,costing more than a replacement-that's not changing parts,that's repairing-big difference..."turning a wrench" in your back yard is a little different than being a certified,trained technician,with the proper diagnostic equipment,tools and insurance,and owning your biz.you,as a private boat owner,can repair your own boat,anyway you see fit,you answer to no one,except yourself,me,if i make a repair against "accepted" methods,i'm responsible.granted,there's more than one way to skin a cat,i stick with what's accepted,and what gives a customer the best option,for reliability,and value.dumping a load of money into an engine that's hydrolocked,is pushing the point of diminishing returns-a carb'd new complete merc 5.7,ready to drop in costs approx $6,900-complete with a 12m warranty-tough to beat-out with the old,in with the new...sure seems like a good deal to me...last repower i did,a volvo 5.7,i found a left over 5.7gsi volvo engine,complete,mpi injected,for under $5,000,with a full warranty from volvo...
again,just good usefull advice...

Re: Mercruiser Woes-What Next?
 

Alright everyone, thanks or the advice. I appreciate everyone's interest and I was fully prepared to get varying opinions on this one.
Having no experience whatsoever with an engine in this condition, it's good to see what others think. I'm pretty sure I caught it right away, as the motor was idling fine one minute on the drift and then started to stagger. As soon as I got the plugs out I was able to turn the engine by hand and expel the water from the failed side and I found the crack in the manifold almost immediately.
Pelican-if you were my mechanic I would appreciate your candor rahter than just throwing parts at my motor. I am done with the guy I've been using-I think he has cost me more money with some of his mistakes. He is a good guy and has some skills, but I want him working on my motor as if it were his own.
I figure since I pickled it right away, have had it running three times now, the oil looks good, my compression is in very good shape and my vacuum looks good (at least in the driveway), it's worth taking the risk and throwing new exhaust on the failed side and seeing what she does with a load on. The most that's going to cost me is $300 bucks in parts-all the labor is being done by yours truly and I'm learning more by the day, which is what this site is all about in the first place.
Last night I pressurized the coolant side with an auto tester both warm and cold and didn't see any fluctuations in the gauge other than it rising slowly as the engine warmed up, but then it held steady, so maybe my smelling coolant is in my imagination.
I won't be rebuilding this motor or buying a long block, either. If she goes she goes, and in comes the new motor from merc. That price is almost exactly what my guy quoted me for that motor-but he has some kind of deal right now from merc. that the motor is coming with 3 years rather than 1, and that's not for the seacore.
Anyway, onward we go. Maybe if we want to discuss AB's exhaust we should start a new thread so people will see it in the title and it will be more useful. I love the civil discourse on this site-
Oh yeah-special thanks to bushwacker for all of the time and patience via pm's. I'm definitely hooking up that permanent vac gauge this winter-just have to figire out where to tee it off and how to run it up to the dash, but I have some ideas.
On go the new manifold and riser tonight. Unfortunately I have to go up to the cape to bury my favorite uncle this week so the boat will wait until next weekend. Sure puts things like this in perspective.
Thanks again everyone.
Doug

Re: Mercruiser Woes-What Next?
 

Worst case scenario it blows up [img]/forum/images/graemlins/tongue.gif[/img].

You take off all the usable parts and sell them on craigslist. And recoup most if not more than the $300.

Mercury has a deal going that if you buy a reman. by the end of the year you can get an extra 2 years of warranty...extending out to 3 years.

What ever you do don't toss the block.

Mercury's new policy is that if you want a 350 w/o catalytic converter. You have to exchange your old block for the new one...(not sure about the parts).

There newest set up is a 377 with a catalytic converter. Its on there website. I went through this on my engine buy.

Re: Mercruiser Woes-What Next?
 

:D :D :o

Re: Mercruiser Woes-What Next?
 

Yep-the dealer told me there is a 300 core charge, so it's not going anywhere if I go that route. 6800 for the new complete motor.
I think merc.'s rebuilds raise the hp to about 300 from 250, as well.
Anyone know how easy it is to swap in my fwc kit to a new motor? I have a relatively new heat exchanger on my current motor-those damn things are expensive!

Re: Mercruiser Woes-What Next?
 

Core charge is different than exchange.

Some dealers use the core charge to boost the price. Do a little of shopping around. Try to find a dealer that sells a lot of Mercruiser engines, and one that knows what he is talking about.

If you want some good info. PM me your phone number and I will give you a call.

Believe me I have done a lot of research and shopping.

Most guys out there that can get M/C. Don't have a clue on whats going on.

Re: Mercruiser Woes-What Next?
 

Be sure to change both of your manifolds, not just the one that is leaking right now. It's pretty much straight forward on swapping your FWC componets over to the new engine. What would be ideal is to have a heat exchanger big enough to cool the manifolds as well, that way you would only be concerned with replaceing the risers when they start to eat away which in the long run would be cheaper. On my Seavette, every thing is FWC for the exception of the risers in which those are made of stainless steel. :cool:

Re: Mercruiser Woes-What Next?
 

Steve is right. Stainless is the way to go, if you can. But don't assume that stainless is a panacea.
I have even seen one of those fail from what was apparently electrolysis damage. It was on a Formula 302 with twin Merc 7.4L 440 hp with the "Silent Thunder" stainless exhaust manifold/riser/muffler systems. The stainless exhaust manifold had what looked like a wormhole going from the water jacket out to the outside of the manifold, spraying a fine mist of saltwater over everything. When we tore it down, the inside had several more of those wormhole-looking defects, but none that made it to the outside (or to the interior, either).