Bravoitis or deeper overheating issue

Discussion in 'Sport Boats' started by Rotorhead58, Aug 2, 2020.

  1. Rotorhead58

    Rotorhead58 Member

    34
    Jun 13, 2020
    Owner of a “new to me” 2007, 260 Sundeck, with a 5.7L, Bravo III.
    Merc 5.7
    Probably a stupid question so apologies up front.
    I have a thru Hull seawater intake on the bottom of my 07 260 (5.7, B3, 350 hrs). With that, can you still experience “Bravoitis”?

    Reason I ask, I overheated today on the water so I’m going to start troubleshooting.

    Original thoughts:
    1. Make sure the lines are clear from the raw water intake.
    2. Check impeller condition and hoses to and from impeller
    3. Last, check water pump.

    Any sign or symptoms I should check, specifically? The boat did go into “guardian mode” I think, and I did notice a small amount of smoke coming from aft of the engine, starboard side, when I stopped the engine and opened the hatch.
     
  2. Jimmy Buoy

    Jimmy Buoy Well-Known Member

    Dec 3, 2008
    Sarnia, Ontario, Canada
    340 Amberjack
    twin 8.1S 370 Hp + 4.5 Westerbeke Genset
    Short answer - no. Bravoitis is referring to the small water supply hose travelling from the outdrive, through the transom assembly to the fitting on that assembly where the cooling water hose is connected to the water pump. This hose becomes pressed closed from the outsides from corrosion of the aluminum around it, eventually choking off most of the water flow to the pump.

    I think your on the right track with your thoughts. Other things to check is that the exhaust manifolds (if the engine is not cooled with antifreeze) are not restricted with corrosion or debris. Is this a salt water or fresh water boat? What was the engine temp gauge reading when it went into limp mode?
     
  3. Ididntdoit

    Ididntdoit Well-Known Member

    Dec 5, 2007
    New England & South Florida
    1976 17 Sport
    90hp Etec
    no - bravoitis is the clogging/collapse of the fitting behind the water neck on the transom assembly - yes, check your thru hull for growth/blockage - yes, check impeller and condition of pump housing (though ive successfully used some pretty beat up housings) - i assume by water pump, you mean the circulating pump (the water pump in an automotive application) you can check this, but i would also check the thermostatat and back flush assuming your raw water cooled - if closed cooling check/rod out the exchanger - how old are your manifolds and risers?
     
  4. Rotorhead58

    Rotorhead58 Member

    34
    Jun 13, 2020
    Owner of a “new to me” 2007, 260 Sundeck, with a 5.7L, Bravo III.
    Merc 5.7
    That’s kind of what I thought as well, but wanted to make sure. I can’t recall the exact temp, due to the alarms and dealing with people on the boat, but when it hit 160, alarms started, then went into limp mode around 165-170 Which was within a few seconds. This is a salt water boat, bought it a month ago, so not sure what the previous owner has or hasn’t done in the past. That being said, thermostats are fairly inexpensive, so I’m going to throw a new one in there so I know it’s good and can easily rule that out.

    The boat maintained temp for about an hr, then really creeped up.
     
  5. Rotorhead58

    Rotorhead58 Member

    34
    Jun 13, 2020
    Owner of a “new to me” 2007, 260 Sundeck, with a 5.7L, Bravo III.
    Merc 5.7
    Circulating pump (thank you). It is raw water cooled; I’m new to boating so I’ll do some research on The back flush. Not sure about manifolds or risers as I had no interaction with the previous owner.

    I’m a prior Army Aviation Crewchief, so keeping up with maintenance, and maintaining records are a main MO of mine.
     
    JC3 likes this.
  6. Ididntdoit

    Ididntdoit Well-Known Member

    Dec 5, 2007
    New England & South Florida
    1976 17 Sport
    90hp Etec
    look into changing the manifolds and risers - 7 years is generaly the life of dry joint manifolds in salt water - a failure can cost you a motor - also, look into a flush kit if yow will be running it in salt....I like the eddie marine one
     
  7. Rotorhead58

    Rotorhead58 Member

    34
    Jun 13, 2020
    Owner of a “new to me” 2007, 260 Sundeck, with a 5.7L, Bravo III.
    Merc 5.7
    I’ll look into manifolds and risers, not sure when they were changed last but probably due if needed every 5-7.

    regarding a flush system, I believe I have one that I use. Black QD located atop the engine on its front starboard side. I use the salt away system. I also use the muffs on the outdrive just to make sure
     
  8. Espos4

    Espos4 Well-Known Member

    Jan 1, 2017
    Long Island NY
    2007 240 Sundeck
    350 MAG Bravo 3 W/DTS
    160° shouldn’t sound an alarm. There should be a 160° thermostat in there.

    I have the same year motor and it runs at 158-160 all day long.

    You may have gotten an alarm for low water pressure which drove up the temp to the 170 range and that’s where it shut down to protect itself.
     
    Rotorhead58 likes this.
  9. Espos4

    Espos4 Well-Known Member

    Jan 1, 2017
    Long Island NY
    2007 240 Sundeck
    350 MAG Bravo 3 W/DTS
    You could also remove one of the plugs on the underside of an exhaust manifold (there are 4 total) to see if they are all blocked up with rust and scale.
     
    Rotorhead58 likes this.
  10. Rotorhead58

    Rotorhead58 Member

    34
    Jun 13, 2020
    Owner of a “new to me” 2007, 260 Sundeck, with a 5.7L, Bravo III.
    Merc 5.7
    Thanks for the great info. I will check this once I get back to the boat and continue to update this thread.

    Item of note, when I first purchased the boat a month ago, the temp stayed constant between 145-150. I had a tech onboard and saw that; stated the previous owner must have put in a lower temp thermostat.

    I did notice that my oil PSI is super high all the time (~50ish) and again, has been that way since ownership with no issues
     
  11. Espos4

    Espos4 Well-Known Member

    Jan 1, 2017
    Long Island NY
    2007 240 Sundeck
    350 MAG Bravo 3 W/DTS
    Lacking records and maintenance history, it’s not a bad idea to set a baseline.
    Manifolds
    Risers
    Plugs
    Cap and rotor
    Fuel filters (yes there are 2)
    Raw water impeller

    If you do wind up replacing the manifolds, replace the plugs while the manifolds are removed. SO much easier.

    It doesn’t take any fancy tools, just some initiative on your part. You seem capable based on your service (Thank you very much for that!)

    One last thing.....you don’t need to be an expert marine mechanic that knows everything......just be an expert on YOUR boat. FYI 50 psi oil pressure is typical while cruising.
     
    Rotorhead58 likes this.
  12. Jimmy Buoy

    Jimmy Buoy Well-Known Member

    Dec 3, 2008
    Sarnia, Ontario, Canada
    340 Amberjack
    twin 8.1S 370 Hp + 4.5 Westerbeke Genset
    Limp mode can also engage if you have sensors in the exhaust manifolds/elbows that got too hot from lack of seawater flow. Not sure if you have those sensors on your boat but look for a pair of wires going to a plastic fitting somewhere on the exhaust system.
     
    Rotorhead58 likes this.
  13. Rotorhead58

    Rotorhead58 Member

    34
    Jun 13, 2020
    Owner of a “new to me” 2007, 260 Sundeck, with a 5.7L, Bravo III.
    Merc 5.7
    Thank you sir, and yes I’m one of those guys who think, “we’ll, if this is off, mine as well replace x,y, and z. Cheers! I’ll keep this post going as I’m sure many others have come across the same, or similar issues.

    I’ve had to be towed in 2/4 times I have taken the boat out. The wife is already regretting the purchase, and understandably so.
     
  14. Rotorhead58

    Rotorhead58 Member

    34
    Jun 13, 2020
    Owner of a “new to me” 2007, 260 Sundeck, with a 5.7L, Bravo III.
    Merc 5.7
    I have built a spreadsheet based off of the service manuals I could find, and have broken them down into systems, as well as simple general maintenance. If anyone would like a copy to build off of for your personal use, I’m more than happy to email you a copy. Let me know!
     
  15. Korkie

    Korkie Active Member GOLD Sponsor

    852
    Feb 2, 2016
    Leonardtown, MD Potomac River / Chesapeake Bay
    340 Sundancer 2006, Garmin 7612, xHD Radome
    Merc 496 Mags
    Bravo III Drives
    All of the above is very true. Also check to see if your thru hull is T'd into the stock raw water supply that comes thru your OD, (as mine is) be sure to check that it is intact and not sucking air from thru the drive due to Bravoitis or bad hose. Been there - experienced that.
     
    Rotorhead58 likes this.
  16. Rotorhead58

    Rotorhead58 Member

    34
    Jun 13, 2020
    Owner of a “new to me” 2007, 260 Sundeck, with a 5.7L, Bravo III.
    Merc 5.7
    Ok so I managed to get in about 2 hrs of overlooking the engine and snapping pics before the weather hit. Below is how I’m going about finding the overheating issue:

    1. Checked thru Hull raw water intake to Seacock- CLEAR
    2. Check hose from seacock to seawater strainer- could not check because I could only get the hose off the seacock. Could not locate seawater strainer.
    3. Once I locate the strainer, will check for any debris and remove. (Believe strainer is located under the engine, Favoring the port side, attached to transom or hull?).
    4. Located hose running from strainer to seawater pump- again, couldn’t verify hose was clear due to not locating strainer.
    5. I did notice a small amount of oil residue on the bottom of the seawater pump housing- could be residual.
    6. Impeller and 160 degree thermostat on order. (How do you replace those parts within the seawater pump? There’s hardly any room whatsoever!)

    Items noticed:
    -Circulating pump: rod connecting pulley to the pump has a noticeable space. Is this normal? (Photo 1)
    -I did notice 4 bolts under each manifold. Port side manifold, second bolt in, is extremely rusted and shows indication of long existing, but slow leak. @Espos4 are these the “plugs” you were referring to?
    -Believe I have a leak in my lower unit system somewhere, as the water in the bilge is oily and the fluid within reservoir is lower than it was a week ago when I topped it off.
    -Tension pulley next to the seawater pump looks like it is at a more acute angle than the seawater pulley like they are unaligned (normal?) (Photo 4). This is causing the belt to favor riding on the forward portion of the tension pulley versus riding in the middle.
    -After running the engine, I notice tiny little pieces of, what I am assuming are from, the belt around the bilge (Photo 7 & 8)
    -Noticed some orange sludge in the bilge, almost like a wet booger consistency...no idea where that could have possibly come from (Photo 10).

    Tomorrow, I plan to finding a hex head large enough to open one of the bolts on the top side of the manifolds to peak in and see the inside condition. Between the severe rust on one of the bolts on port side manifold and the gaskets between the risers on stbd side (Photos 5&6), I feel like I will be replacing them sooner rather than later.
     
    Last edited: Aug 8, 2020
  17. Rotorhead58

    Rotorhead58 Member

    34
    Jun 13, 2020
    Owner of a “new to me” 2007, 260 Sundeck, with a 5.7L, Bravo III.
    Merc 5.7
    395813D5-F93E-4C21-A0CC-A5CAB4129EC6.jpeg 54BC74EE-9FCD-4E3E-B4FB-32EF2E166E1F.jpeg A5510126-24FA-4D31-B31F-5B96A3078C70.jpeg 76E94568-DE7A-4F9F-845D-DCB9DC28B2AD.jpeg 7A01EA54-B119-4E44-A51E-1F1006F34F73.jpeg 315D041F-105D-4D2D-A85C-FBB64B0445F6.jpeg BFCE3CBA-852C-4D4C-828F-49A445A35521.jpeg 119CA7BA-4057-426C-9C09-2CD3F078D3A0.jpeg C8C762D5-F44B-4CE8-BF5E-92B2B8BBA19D.jpeg 3BBBDAE9-8EE8-4D20-A52A-C0A070F35C73.jpeg 395813D5-F93E-4C21-A0CC-A5CAB4129EC6.jpeg 54BC74EE-9FCD-4E3E-B4FB-32EF2E166E1F.jpeg A5510126-24FA-4D31-B31F-5B96A3078C70.jpeg
     
  18. Jimmy Buoy

    Jimmy Buoy Well-Known Member

    Dec 3, 2008
    Sarnia, Ontario, Canada
    340 Amberjack
    twin 8.1S 370 Hp + 4.5 Westerbeke Genset
    Ok, you've done a fair bit of investigation. That's helpful. Not sure what your experience is with boats, so please don't think I'm talking down to you with my comments. I'm also no expert, but have had some experience maintaining my own boats for 30+ years. Hope something helps you.

    First, it is entirely likely that the previous owner had an overheat issue and installed the thru-hull water supply for the engine without integrating a strainer at all to correct the issue. There is no strainer on the stock application from the outdrive and even my last boat with inboard 5.7 Crusaders had no strainers (although it was in fresh water) so its not unheard of not to have strainers. If you have to look that hard, its probably non-existent since they are quite large and must be accessible for maintenance.

    Secondly, lets clarify that the engine has two pumps - a "circulating pump" which is driven by a pulley on the front and centre of the engine. It circulates water in and out of the engine block and has a metal impeller. If anything, the seals can start to leak on the shaft and you will see weeping of coming out of the "weeping hole" at the bottom of the unit near the shaft/pulley.
    The other pump is called the "fresh water (or seawater)" pump. It is what draws water from underneath the boat and sends it first to an oil cooler, then to the engine which accepts it or rejects it based on the thermostat's position. Excess water is sent to the exhaust manifolds to finally exits along with exhaust gasses.

    The freshwater pump should be removed, cracked open, and its rubber impeller inspected. It can be a bit of a job to remove the two in/out hoses, pulley belt, and brackets but its usually impossible to replace the rubber impeller and check the bearings and seals without the pump removed. This pump starting to fail is a typical cause of overheating.

    The space you mentioned on your circulating pump looks ok. It does have to clear the pulley studs.

    The four bolts mentioned on the exhaust is what is holding the assembly together. There's the exhaust manifold attached to the exhaust ports and has an inner and outer chamber. Inner is open to the exhaust ports and should have no water. The outer has seawater flowing through it to cool the manifold while operating. It appears that you then have a "riser" on top of the exhaust manifold. The riser like the manifold has two chambers and you can see the round water supply coming from the manifold to the riser. The riser is there to increase the height of the exhaust water flow to prevent it backing into the engine's exhaust ports. Next is the "exhaust elbow which is again a dual chamber system with its water flow coming from two areas which you can see from the hoses connected from both the riser and water pump system. Water exits from the tip of this elbow where the rubber hoses attach which keeps the hose cool enough so exhaust gasses don't burn the rubber. The problem with the system is all those specific gaskets between each part not always doing their job. Evidence of problems is rust on the outside (which you have) and even worse, rust/water on the inside which can collect at the exhaust ports causing rust damage and even hydro-lock if it is enough at one time which can wreck your engine upon start up. At the least, the gaskets that are leaking need to be replaced. When apart, check for the condition of the cast iron parts.

    Regarding your drive fluid reservoir, it could be a crack in the plastic itself or a leaking o-ring causing your fluid to drop. Fairly easy to remove and check. If it's not leaking from there or the hose going to the outdrive, it may be your prop shaft seal leaking which is harder to detect without an outdrive pressure test.

    The tension pulley mentioned appears to be off kilter. When the belt is off check the pulleys for play. The bearings could be shot. A new idler pulley isn't a big deal to replace.

    With the rust that I see on pulleys, wear on the belt is a real possibility so it's not hard to connect that with the rubber "dust" around the belt. Rust acts like sandpaper as everything rotates.

    Your orange slush looks more like old engine oil mixed with water over time. I'd clean up the bilge then look for new leaks and address as needed.

    Good luck with her!
     
  19. Rotorhead58

    Rotorhead58 Member

    34
    Jun 13, 2020
    Owner of a “new to me” 2007, 260 Sundeck, with a 5.7L, Bravo III.
    Merc 5.7
    This helps, thank you! I am new to boating (this is my first, with 8 hrs of my own use on it), so your response was great. I did know all that you stated regarding the 2 specific pumps and how they operate, through research, but how the manifolds are built and operate, is new to me.

    With having friends and family (3 boys 6 and under) always onboard, I’m tempted to just pull the engine and get it on a stand so I can easily access the raw water pump, tear it apart, and rebuild it if needed. Replace all of the gaskets, and probably replaces the risers and manifolds, dependent upon the inside inspection (which I’m assuming is worse than what the outside looks like). But I’m putting the horse before the cart here. Great call on the weeping hole on the circulation pump, I’ll keep an eye out for that.

    I see a lot of expenditures in the near future but I need a peace of mind or I won’t enjoy it. Still cheaper than buying a new boat I guess.
     
  20. Jimmy Buoy

    Jimmy Buoy Well-Known Member

    Dec 3, 2008
    Sarnia, Ontario, Canada
    340 Amberjack
    twin 8.1S 370 Hp + 4.5 Westerbeke Genset
    Looks like you're on your way to better boating days. I've taken the water pump off a single I/O in the past and it really wasn't that bad. Depends on the room in front of the engine but I wouldn't go pulling the engine before giving it a try. Manifolds are also not a really hard job for a single I/O while in the boat. It will definitely be cheaper than buying a new boat and doing the work yourself along with shopping for parts online will keep it down to a minimal amount gives you a great sense of satisfaction!
     
    Rotorhead58 likes this.

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