• Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-

65 mustang 289 heater core by-pass question

  • Thread starter Thread starter Woody3882
  • Start date Start date Sep 17, 2021

Woody3882

5 Year Member
Jun 19, 2018
84
9
18
Bradenton Fl 34212
Sep 17, 2021
#1
  • Sep 17, 2021
  • #1
I have a 65 Mustang with the original 289. I live in Florida so the heater is not needed. Long ago I removed the heater hoses and just capped the hose outlet and inlet at the manifold. (not the core)
I was recently told that instead of just capping off the inlet and outlet fittings on the manifold, I should have put on a by-pass hose from the inlet port to the outlet port. The explanation given to me was that the water would be circulating and give better cooling through the manifold with the bypass hose instead of just capping the 2 ports.
Does it make a difference if the ports are capped or if there is a hose from one port to the other ?
If a by-pass hose is better, does anyone know the part number for the bypass hose.
Thanks for your advise and time, I appreciate it.
 
J

jws66m

Member
Oct 5, 2018
47
7
18
Utah
Sep 27, 2021
#2
  • Sep 27, 2021
  • #2
any hose and loop it. doubt there is a part #
 

Woody3882

5 Year Member
Jun 19, 2018
84
9
18
Bradenton Fl 34212
Sep 27, 2021
#3
  • Sep 27, 2021
  • #3
The fittings are two different sizes, "any hose" will not properly fit.
 
J

jws66m

Member
Oct 5, 2018
47
7
18
Utah
Sep 27, 2021
#4
  • Sep 27, 2021
  • #4
I'm sorry I remember my heater hoses to be the same size. I will look again. Put a different connector on one of the ends and make them the same size. You just want circulation.
 
Reactions: manicmechanic007

manicmechanic007

5 Year Member
Sep 26, 2017
2,534
714
143
Roy, Utah
Oct 5, 2021
#5
  • Oct 5, 2021
  • #5
You can man handle the 5/8 hose to fit over the 3/4 hose bib
Otherwise you can but a Taurus bypass hose from say a 95 3.8
It has 5/8 on one end and 1 inch on the other
You can cut it in the middle where its 3/4
 

manicmechanic007

5 Year Member
Sep 26, 2017
2,534
714
143
Roy, Utah
Oct 5, 2021
#6
  • Oct 5, 2021
  • #6
I would like you to just replace the core
The car needs the additional heat exchanger
That core removes heat from the heads and intake before the coolant thermostat opens
The engine will run a bit hotter with no heater core
The heater case needs to be removed for this repair
Not all that tough though
 

Woody3882

5 Year Member
Jun 19, 2018
84
9
18
Bradenton Fl 34212
Oct 5, 2021
#7
  • Oct 5, 2021
  • #7
Thank you, that is the answer I was looking for
Thnaks
 
Reactions: manicmechanic007
You must log in or register to reply here.

Similar threads

M
2001 evap/heater core questions
  • mnky99
  • Sep 3, 2025
  • SN95 V6 Mustang Tech
Replies
3
Views
318
SN95 V6 Mustang Tech Sep 3, 2025
mnky99
M
M
2001 v6 heater hose quick connect question
  • mnky99
  • Sep 24, 2025
  • SN95 V6 Mustang Tech
Replies
8
Views
585
SN95 V6 Mustang Tech Sep 26, 2025
mnky99
M
C
Paxton novi 1200SL
  • Cambo617
  • Oct 9, 2025
  • 2005 - 2009 Specific Tech
Replies
0
Views
160
2005 - 2009 Specific Tech Oct 9, 2025
Cambo617
C
M
Progress Thread mnky99 2001 V6 evap core, ac compressor, heater core replacement
  • mnky99
  • Sep 5, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
1
Views
509
1996 - 2004 SN95 Mustang -General/Talk- Sep 5, 2025
mnky99
M
N
Edelbrock 1405 Setup
  • nathantaylor200
  • Nov 4, 2025
  • Classic Mustang Specific Tech
Replies
3
Views
243
Classic Mustang Specific Tech Nov 5, 2025
nathantaylor200
N
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?