Go Back  Offshoreonly.com > Technical > General Q & A
496 HO - Overheat and High water PSI >

496 HO - Overheat and High water PSI

Notices

496 HO - Overheat and High water PSI

Old 08-02-2020, 02:54 PM
  #1  
Registered
Thread Starter
 
Join Date: Apr 2012
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Angry 496 HO - Overheat and High water PSI

Hey all, fighting a gremlin in my 496HO.

She is running super high water pressure, and when idling, going slow, she will overheat. It also will build temperature and the pressure is off the charts on the garden hose. I don't have to flush through the drive. At idle it is running around 15psi (way too high) the pressure has gotten worse since I've done everything below. I am also thinking the high pressure is related to the overheat?

I have the Hardin upgraded sea water pumps, I just replaced the wear plates and impeller. I changed all the temperature senders and sensors, I installed the high flow thermostat from CP, I thought I may have had the Bravoitis issue so I changed that hose as well. I pulled the heat exchanger and cleaned, I pulled the power steering cooler and cleaned. I can't get to the oil cooler easily but thought I did a decent job of backflushing. Maybe this is my issue? But i don't know. I have the EMI thunder exhaust setup for the 496.

I am completely baffled with this any input is greatly appreciated. Thank you!
TitanBry77 is offline  
Old 08-02-2020, 04:44 PM
  #2  
Registered
 
Join Date: Oct 2012
Posts: 1,521
Received 64 Likes on 44 Posts
Default

Check your oil cooler
underpsi68 is offline  
Old 08-02-2020, 06:13 PM
  #3  
Registered
iTrader: (1)
 
Join Date: Nov 2009
Location: KY
Posts: 3,044
Received 124 Likes on 103 Posts
Default

Water builds pressure only if there is a restriction. The more restriction the more pressure, less get less pressure.

Its not Bravoits because that would cause less pressure.

Is motor thru hull or thru the prop?
If thru the prop, which drive and have you checked if the water shutters have broken off?

Where is the sensor located and assuming electric gauge?
AllDodge is offline  
Old 08-02-2020, 11:44 PM
  #4  
Registered
 
Expensive Date's Avatar
 
Join Date: May 2006
Location: West Creek NJ
Posts: 4,227
Received 1 Like on 1 Post
Default

High water pressure you have a restriction somewhere, When I get high water pressure its the steering cooler on back of engine
Expensive Date is offline  
The following users liked this post:
mike tkach (08-03-2020)
Old 08-03-2020, 01:47 PM
  #5  
Forum Regulator
VIP Member
iTrader: (1)
 
Sydwayz's Avatar
 
Join Date: May 2001
Location: Worldwide
Posts: 22,950
Received 151 Likes on 79 Posts
Default

How do you hook it up to the hose? Do you have a fresh water fitting with a Tee into the system?
Sydwayz is offline  
Old 08-03-2020, 06:46 PM
  #6  
Registered
 
Join Date: Oct 2012
Posts: 1,521
Received 64 Likes on 44 Posts
Default

Originally Posted by Expensive Date View Post
High water pressure you have a restriction somewhere, When I get high water pressure its the steering cooler on back of engine
Steering coolers on 496 are straight thru, no tubes (at least all the ones I've seen).
underpsi68 is offline  
Old 08-03-2020, 07:34 PM
  #7  
Registered
iTrader: (1)
 
Join Date: Nov 2009
Location: KY
Posts: 3,044
Received 124 Likes on 103 Posts
Default

Not saying this is the case, but there was a PS cooler posted here where it was almost closed off from assuming over pressurizing, and it was not leaking
AllDodge is offline  
Old 08-04-2020, 10:13 AM
  #8  
Registered
Thread Starter
 
Join Date: Apr 2012
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Sydwayz View Post
How do you hook it up to the hose? Do you have a fresh water fitting with a Tee into the system?
Yes it has a fitting, tee some sort of Perko fitting/valve.
TitanBry77 is offline  
Old 08-04-2020, 10:14 AM
  #9  
Registered
Thread Starter
 
Join Date: Apr 2012
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by AllDodge View Post
Water builds pressure only if there is a restriction. The more restriction the more pressure, less get less pressure.

Its not Bravoits because that would cause less pressure.

Is motor thru hull or thru the prop?
If thru the prop, which drive and have you checked if the water shutters have broken off?

Where is the sensor located and assuming electric gauge?
It is a pressure fed gauge that is fed from a tap right off the sea water pump. It is through hull exhaust.
TitanBry77 is offline  
Old 08-04-2020, 10:23 AM
  #10  
Registered
iTrader: (1)
 
Join Date: Nov 2009
Location: KY
Posts: 3,044
Received 124 Likes on 103 Posts
Default

I need a serial number please?
AllDodge is offline  

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.