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Mercruser 4.5 Bravo 3 Low Block pressure Alarm

Posted: Sat Feb 27, 2021 12:22 pm
by dogwspts
Remember this post finally found a dealer he has it now. I will post if it can be fixed. Been haunting me for two years.

Re: Mercruser 4.5 Bravo 3 Low Block pressure Alarm

Posted: Sat Feb 27, 2021 1:33 pm
by Big Block Power
Seriously this is still acting up? Man I thought you got it last year. That sucks

Re: Mercruser 4.5 Bravo 3 Low Block pressure Alarm

Posted: Sat Feb 27, 2021 5:16 pm
by ajcampen
So what does dealer think it is?

Re: Mercruser 4.5 Bravo 3 Low Block pressure Alarm

Posted: Sat Feb 27, 2021 8:03 pm
by bruceb58
dogwspts wrote: Sat Feb 27, 2021 12:22 pm Remember this post finally found a dealer he has it now. I will post if it can be fixed. Been haunting me for two years.
Out of curiosity, what is your pressure?

Re: Mercruser 4.5 Bravo 3 Low Block pressure Alarm

Posted: Sat Feb 27, 2021 8:20 pm
by dogwspts
Idle at 3. 3000 for the first hour 18. then after about 30 min through a no wake zone and back to 3000 it drops to 8 and has been as low as 5.changed sensors and inpeller only 130 hours on motor.

Re: Mercruser 4.5 Bravo 3 Low Block pressure Alarm

Posted: Sun Feb 28, 2021 12:12 am
by bruceb58
dogwspts wrote: Sat Feb 27, 2021 8:20 pm Idle at 3. 3000 for the first hour 18. then after about 30 min through a no wake zone and back to 3000 it drops to 8 and has been as low as 5.changed sensors and inpeller only 130 hours on motor.
Are you sure the correct impeller is installed? There are two versions. Your engine likely needs the earlier version....like mine


Look at the picture below. You likely have the first design. Depends on serial number

Image

Re: Mercruser 4.5 Bravo 3 Low Block pressure Alarm

Posted: Sun Feb 28, 2021 10:57 am
by dogwspts
Yep did it with the factory impeller also

Re: Mercruser 4.5 Bravo 3 Low Block pressure Alarm

Posted: Sun Feb 28, 2021 4:10 pm
by bruceb58
dogwspts wrote: Sun Feb 28, 2021 10:57 am Yep did it with the factory impeller also
Ok...as long as you used the correct factory impeller.

Did you do the flow test as outlined in the factory service manual? 1000rpm...15 second... I can't remember the volume. You have to do it in the water

Re: Mercruser 4.5 Bravo 3 Low Block pressure Alarm

Posted: Sun Feb 28, 2021 4:20 pm
by Big Block Power
bruceb58 wrote: Sun Feb 28, 2021 4:10 pm
dogwspts wrote: Sun Feb 28, 2021 10:57 am Yep did it with the factory impeller also
Ok...as long as you used the correct factory impeller.

Did you do the flow test as outlined in the factory service manual? 1000rpm...15 second... I can't remember the volume. You have to do it in the water
Bruce if you search his issues you will find about 10 threads in here. He has some specs in each of them. Sorry. This has been going on for 2 years like he said. Im still surprised he still owns this boat it would have been traded in a long time ago if it was me and no one had been able to fix it. Just me.

Re: Mercruser 4.5 Bravo 3 Low Block pressure Alarm

Posted: Sun Feb 28, 2021 6:30 pm
by dogwspts
Hope this time is the Charm.

Re: Mercruser 4.5 Bravo 3 Low Block pressure Alarm

Posted: Sun Feb 28, 2021 6:33 pm
by dogwspts
Sorry if this got on someones nerves but . The boat does good except for this and I am going to find the problem.

Re: Mercruser 4.5 Bravo 3 Low Block pressure Alarm

Posted: Sun Feb 28, 2021 6:33 pm
by dustinm
dogwspts wrote: Sun Feb 28, 2021 6:30 pm Hope this time is the Charm.
Did they find a cause?

Re: Mercruser 4.5 Bravo 3 Low Block pressure Alarm

Posted: Sun Feb 28, 2021 6:36 pm
by dustinm
dogwspts wrote: Sun Feb 28, 2021 6:33 pm Sorry if this got on someones nerves but . The boat does good except for this and I am going to find the problem.
You were never on anyone's nerves. They are just disappointed that the dealers have not found a fix for you.

Re: Mercruser 4.5 Bravo 3 Low Block pressure Alarm

Posted: Sun Feb 28, 2021 6:41 pm
by ajcampen
dustinm wrote: Sun Feb 28, 2021 6:36 pm
dogwspts wrote: Sun Feb 28, 2021 6:33 pm Sorry if this got on someones nerves but . The boat does good except for this and I am going to find the problem.
You were never on anyone's nerves. They are just disappointed that the dealers have not found a fix for you.
+1

Re: Mercruser 4.5 Bravo 3 Low Block pressure Alarm

Posted: Sun Feb 28, 2021 6:44 pm
by Big Block Power
ajcampen wrote: Sun Feb 28, 2021 6:41 pm
dustinm wrote: Sun Feb 28, 2021 6:36 pm
dogwspts wrote: Sun Feb 28, 2021 6:33 pm Sorry if this got on someones nerves but . The boat does good except for this and I am going to find the problem.
You were never on anyone's nerves. They are just disappointed that the dealers have not found a fix for you.
+1
Correct is not on my nerves. You've gone after this for so long and it's not fixed! I give you credit to keep going after it. I just don't deal with headaches. I want to enjoy boating or what ever. So I would have moved on 2 years ago. Let's get it fixed and let's post the fix!
AJ dealt with his and fixed it I think the first year. I know he was getting frustrated as well.
Plus I was only pointing out to Bruce which is newer here that there are a bunch of your threads on here if he wanted to search them for specs and stuff like that.