1996 5.7l EFI with Bravo 1 overheating immediately.

thumpar

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Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

Will the single piece unit mount up if the unit is originally the multi piece?
 

thumpar

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Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

It is the multi piece unit but now that I got in there It doesn't look as bad as I thought as far as changing it. There is an access panel between the engine and storage bay under the sundeck that gives me good access and big enough for me to climb in. I will open up the pump tomorrow afternoon and take a peek.
 

achris

More fish than mountain goat
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May 19, 2004
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Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

It is the multi piece unit but now that I got in there It doesn't look as bad as I thought as far as changing it. There is an access panel between the engine and storage bay under the sundeck that gives me good access and big enough for me to climb in. I will open up the pump tomorrow afternoon and take a peek.

Oh, the pictures in the mind. :facepalm:
 

BIGALF

Petty Officer 1st Class
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Dec 31, 1969
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Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

I just fixed my 5.7EFI and found the thermostat was stuck in a partial open position and was so rusty it would not move at all. Changed the thermostat and boat runs great now. Look at the thermostat first. It's the easiest and cheapest thing to do first. My Bravo lll pump also had to be replaced due to the pump housing breaking a part inside and wiping out the impeller. Two different issues but when you check out the pump make sure you also check the thermostat. Your alarm might be connected with the thermostat.
 

thumpar

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Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

I just fixed my 5.7EFI and found the thermostat was stuck in a partial open position and was so rusty it would not move at all. Changed the thermostat and boat runs great now. Look at the thermostat first. It's the easiest and cheapest thing to do first. My Bravo lll pump also had to be replaced due to the pump housing breaking a part inside and wiping out the impeller. Two different issues but when you check out the pump make sure you also check the thermostat. Your alarm might be connected with the thermostat.
Thermostat was checked. It closes and starts to open at 160. It is fully open at 170.
 

thumpar

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Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

This would explain the problem.

photo.JPG

Now when I go to put the new one it which way do I twist to make the fins go in the right direction. There is not enough left to know how it was before.
 

achris

More fish than mountain goat
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Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

Looking at the pump from the front, the shaft turns clockwise, so the blades/fins will lag to the left (at the top).... :D

Chris.......
 

QC

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Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

Remember to back flush the lines from the pump to the engine to get the little pieces out ;)
 

thumpar

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Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

Yep, got it all backflushed. All the pieces came out and the water flow is more than our water supply can handle so I know it is clear. I am just waiting on the parts to arrive tomorrow morning.

This is a new engine/drive combo for me. Do the engine driven pumps just explode like that? We were out 2 days before this and had no issues. We launch and then overheat within 10 minutes. What is the recommended change interval? We boat about 15 hours a year with the engine running.

Thanks for everyone's help. I am still learning this setup. The 120 with alpha was smaller and I had it down.
 

MarkSee

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Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

Do the engine driven pumps just explode like that? We were out 2 days before this and had no issues. What is the recommended change interval? We boat about 15 hours a year with the engine running.

Should not disintegrate like that and seems maybe something else was going on that caused that.
I've replaced mine the first couple of seasons albeit maybe with only 30 hours or so each season and the impeller still looked really good; changed it anyway.

Many change impellers annual annually but depending on hours, you can go a couple of seasons.

Could your drive and picked up sand or mud? Ran dry for any length of time?

Mark
 

thumpar

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Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

There was no dry running or sand on my part. My only guess is that it was worn and lost a fin that took out the others. This is a new to us boat just over a month ago. We have receipts for all the maintenance done but who knows. It turned out to be a single piece housing and it had pits in the back side. I ordered the kit with everything.
 

achris

More fish than mountain goat
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Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

There was no dry running or sand on my part. My only guess is that it was worn and lost a fin that took out the others. This is a new to us boat just over a month ago. We have receipts for all the maintenance done but who knows. It turned out to be a single piece housing and it had pits in the back side. I ordered the kit with everything.

:thumb:
 

MarkSee

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Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

I ordered the kit with everything.

Yep; exactly what I did also for those 2 changes to give myself a secure feeling the entire water pump assembly at its best each time.

Mark

edit: Chris, you type 90 words a minute don't you?????...or at least find those little things really quick...
 
Last edited:

achris

More fish than mountain goat
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Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

..edit: Chris, you type 90 words a minute don't you?????...or at least find those little things really quick...

:D No, I just remember the text for them... Like that 'thumbs up' one is a colon, then the word 'thumb', then another colon...
This :welcome:, is again the colon, then the word 'welcome', then a colon...

When posting a reply, you can go to the 'advanced' and you get a few of them on the right hand side, then under those is the click-able link 'more'. Click that and you get 2 pages of the little buggers :eek:. Under each of the little smileys is the text. I only ever use a few, so remembering them isn't to hard. ;)

Chris......
 

thumpar

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Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

Why are we chatting about colons now?:)


Sorry had to.
 

84EdH

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Apr 30, 2011
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Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

Now that colon discussion is over, I would like to jump in to the fray. I have a theory on the super quick over heating issue. This is how I read your initial problem: once the alarm sounds, the water temp is very hot. You kill the engine, wait until dash temp drops to normal. Re-start, dash guage jumps after a few seconds.

So, here is my scenario: impeller goes out, water temp goes up, engine shut down. after 10 minutes or so dash guage reads normal, because it is reading the water temp in the senders near vicinity. the rest of water in the block, between cylinders etc. is still over 160. you start the engine, the engine water pump pushes the still hot water up to the temp sender and dash guage says your overheating again. almost immediately. If you keep engine running, in fact, you are overheating again due to impeller not supplying raw water.

Yes? :rolleyes:
 

QC

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Mar 22, 2005
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Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

Yes. It is called heat soak, and is very probably what went on.
 

thumpar

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Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

Everything is back together and the issue is fixed just in time to start preparing for winterizing :grumpy:. Thanks for the advice.
 
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