2006 5.0L MPI Over heating - changed everything!

[JJB4]

Fun Times,

Issue was present when I bought the boat back in April. Came with the SE 116 installed, not sure how old it is. Boat originally came with Merc. Alpha 1 Gen 2, ratio = 1.62.

Started it up today in the water, temp started climbing, risers too hot. Shut it off after 10 mins.

 

[maicoman]

JJB4 stop playing around and do what I said.Mercury does not make this system anymore.All the hoses that are connected to the bottom distributor ,or whatever they call it are just drain hoses.Technically if one or a few of those hoses are "leaking" a bit your system is not flowing.It is very simple without any of those drain hoses connected,you toss the little distributor tube and the garden hose spigot in the trash.Water comes directly to thermostat housing from fuel cooler or power steering,then water goes directly to water pump and right into block.I have Thermostat housing part number 864592T1 and hose from thermostat to water pump is 864703A!. Look at Service manual 24 page 6a-25.My boat was older than yours so I will check the numbers for you.

 

[maicoman]

Before I check the numbers I just have to say your dealing with a system which was not engineered correctly.The single drain system was dumped because it does cause problems.Why try to train a pig to run in the Kentucky Derby,it may run but your not going to win.A boat with over heating problems will get an anchor thrown thru the deck eventually.Stop trying to play expert mechanic and fix the stupid thing right.lose the single point.

 

[nateo]

Here is your solution to this problem.Get rid of the single point drain system.The extra hoses and bi-directional water paths make this system useless.I had the system on my Sea Ray and changed to 3 point and its 160 all day,On your PDF it says single point and 3 point ,go to 3 point and compare and study the water flow.It is very easy to discard the unnecessary parts.Look at the bottom of the water pump,how can water have 2 paths there nonscence.Its not expensive and you will love your motor again ,trust me or you will be flushing forever.You must buy a new Thermostat housing and a few hoses but nothing too expensive.The moderators of this site should warn all single point owners to scrap the system it is too troublesome.

I've been troubleshooting very similar problem on my boat (see thread attachment).

 

[maicoman]

Maicoman, thanks for your input. Yes, I'm a bit confused with the water flow path of the single point drain system. Looks like the water 'should' flow in through the water pump, then out through the thermostat, to the manifolds and to the water pump again. I'm a bit disturbed that the stock system can't work though. It should work - not sure if merc is still producing the single point drain systems.

If all else fails, I think I will take your advice and convert to the thermostat housing that has a single water in, and single flow out to the water pump. Looks like merc part# 864592T1. Thanks!

​Water always flows to the thermostat housing first even in the crappy single point thru the T fitting.The T at the input to the water pump has to be the problem because its only function on the bottom of the T is to drain water.It takes an hour or two to go and re do it,trust me it works I did it !!!

 

[maicoman]

Nateo Stop looking all over and take my advise ,lose the single point drain.Just looking and the diagram gives you a headache does it not.Look up the diagram for the 7 point drain and replace the parts.Its easy and it works !!!

 

[nateo]

JJB4 stop playing around and do what I said.Mercury does not make this system anymore.All the hoses that are connected to the bottom distributor ,or whatever they call it are just drain hoses.Technically if one or a few of those hoses are "leaking" a bit your system is not flowing.It is very simple without any of those drain hoses connected,you toss the little distributor tube and the garden hose spigot in the trash.Water comes directly to thermostat housing from fuel cooler or power steering,then water goes directly to water pump and right into block.I have Thermostat housing part number 864592T1 and hose from thermostat to water pump is 864703A!. Look at Service manual 24 page 6a-25.My boat was older than yours so I will check the numbers for you.

maicoman, do you happen to know what part number would be needed to replace the fitting on the bottom of the exhaust manifolds (so I can get rid of the extra hose)?

 

[maicoman]

Nateo I have not had my Sea Ray for many years now,If I remember correctly all you need is a manual drain fitting so you can winterize at end of year.The dealer will have the part it is common Sorry I believe there will be more of these manual fitting anywhere that the hoses are deleted .Engine block both sides etc etc.It is very easy to change simple fitting to a manual shut off one.Try 22-862210A01 this is a 90 degree valve with the famous blue knob.The engine block cutoffs will be different now that I remember.The single point system has a different fitting with 2 hoses the number I gave you is just for the exiting water so only one hose connects.Toss the drain hose you don't use it

 

[nateo]

Nateo Stop looking all over and take my advise ,lose the single point drain.Just looking and the diagram gives you a headache does it not.Look up the diagram for the 7 point drain and replace the parts.Its easy and it works !!!

I priced it out and I came up with about $650 in needed parts, hoses, etc. can't help but think there may be a blockage somewhere (haven't pulled every single hoses, there's a lot of them)

 

[nateo]

Nateo Stop looking all over and take my advise ,lose the single point drain.Just looking and the diagram gives you a headache does it not.Look up the diagram for the 7 point drain and replace the parts.Its easy and it works !!!

I agree about the diagram. The single point system makes it more difficult to test as well. Only downside is the $650 test. This guy had the exact same symptomsas me (went up to 195) and he indicated replacing his manifold resolved his issue:

 

[maicoman]

How much is your time worth.If you perform the 650 dollar operation I believe your boat will be better than ever ! Priceless I think but some like the struggle.

 

[maicoman]

Manifolds and elbows are dispensible items when used in salt water so I would change those in addition to the 650 operation,then you can be assured no problems.BOAT Bust out another thousand !! No getting around these ineviabilities.

 

[nateo]

Manifolds and elbows are dispensible items when used in salt water so I would change those in addition to the 650 operation,then you can be assured no problems.BOAT Bust out another thousand !! No getting around these ineviabilities.

lol..true...true...

I have a bunch of the parts on the way and already ripped out most of the stuff that needs to go, going to give it a shot. Did you get the stuff needed to cool the elbows or did you plug those and run full flow gaskets?

 

[JJB4]

Update on my original issue. After my last test the engine started to make a couple of periodic beeps. So, not wanting to spend $700 on the merc. diag. unit, I called someone to check it out (hate to admit defeat). Showed 'Low Block Flow'. So definitely starving for water. Anyway, after about 2 hours of going through everything with him, running it, testing etc., he decided to pull off the drive to take a look at it even though I had done it previously. He discovered something interesting - if you look in the water port hole in the upper unit, there was a partial metal blockage. Tried to knock it free, but it wouldn't budge. So, I called SEI and explained the issue and he said he has seen a few times when the casting has some slag left over. He said to try and knock it out, and if not send it in since it is still under warranty. Will mail it this afternoon. I can't see how this drive unit ever worked, and I'm a little surprised it wasn't caught by QA. Maybe that's why the guy before me sold this boat. Will report back in a couple of weeks with the outcome. Fingers crossed - this should be it.

 

[Rick Stephens]

Wow... well, that is the difference between a $1200 after market drive and a $3k OEM Merc. They will make it good, though. Their warranty is honored. Which sometimes is harder to say about Mercruiser. Mercruiser can get fussy about warranty terms while SEI covers almost anything within the warranty period.

 

[maicoman]

JJB4 Good catch ;but,even if you remove slag the single point will bring you down.Wait and see how nateo operation goes and then you may see the light.

 

[maicoman]

Nateo Look at the hoses coming out of the thermostat housing.There are still going to be a hose going to the exhaust manifold in addition to a hose going to the riser and or elbow.A total of 6 hoses are connected to the thermostat.Water stays in the engine block engine manifold loop until the thermostat opens and then the loop water is also released.If I remember the gasket between the exhaust manifold and the riser or elbow has that little hole block off gasket.The little hole lines up with the input (under) the upper hose but between the exhaust and the riser or elbow.Riser to elbow ofc will be full flow.Please take diagram to parts man and he will be able to give you correct gaskets.Nateo I know the different types of gaskets can be confusing,when you do this job and/if you do not change the manifolds and risers and elbows the gaskets that are in your boat will be right.You are not changing any flow pattern.If you decide to replace manifolds etc take picture or remember which gasket is where.

 

[nateo]

redacting

 

[maicoman]

Your welcome Nateo and happy boating !!! JJB4 are you listening ?

 

[QBhoy]

Really interesting reading here....
Are we certain it's to do either the 7/3 point drain system ?
Did you try it with the thermostat removed completely ?