Notices
1997 - 2003 F150 1997-2003 F150, 1997-1999 F250LD, 7700 & 2004 F150 Heritage
Sponsored by:
Sponsored by: Auxito

No flow through heater core

Thread Tools
 
Search this Thread
 
Old Jan 26, 2015 | 04:58 PM
  #1  
brobrad's Avatar
brobrad
Thread Starter
|
Senior User
Joined: Oct 2011
Posts: 485
Likes: 1
No flow through heater core

My f150 has a 3.9 cummins diesel in it. I run wvo. There was a delay in heat getting to the heater core as coolant went thru heated filter, heat exchanger, and heated tank I simply took tee's out and ran it all in series and switched flow direction (I think)! Now the coolant does not flow through core. Is there a check valve in the heater core or perhaps too much pressure with direct flow?
 
Reply
Old Jan 26, 2015 | 08:25 PM
  #2  
steve(ill)'s Avatar
steve(ill)
Hotshot
20 Year Member
Joined: Jul 2005
Posts: 11,932
Likes: 181
flow thru the core is dependent on one side being higher pressure than the other. Original install was one hose toward the suction side of the water pump and one hose toward the pressure side of the water pump........ 30 years ago I worked in a test facility that tested "new design equipment"... we had a few "heaters don't work"... we ended up putting hoses closer to the pump discharge, and closer to the suction side to get a bigger differential between the two hoses........... I might add, these were Cummins construction engines........... you might see if there is a pipe plug closer to the pump to get better DIFF PRESSURE between the hoses.
 
Reply
Old Jan 27, 2015 | 12:08 AM
  #3  
brobrad's Avatar
brobrad
Thread Starter
|
Senior User
Joined: Oct 2011
Posts: 485
Likes: 1
I understand the pressure differential. I rerouted all of my lines with the Tee's in place yesterday. I had heat to my heater core, but none to the Flat plate heat exchanger or heated tank. SOOOOO, tonight I removed the line from the rear of the block and went back to the original in and out locations with all components in series rather than with tees running coolant to my components. NO FLOW AGAIN. I will most likely have to reinstall the setup with the tees in place. I suppose pushing the coolant through the smaller 1/2" hose with fittings doesn't create enough differential pressure. Going back to square one after all these hours of work is not cool. I suppose another option would be an electric circulation pump to boost the flow.
 
Reply
Old Jan 27, 2015 | 07:58 PM
  #4  
steve(ill)'s Avatar
steve(ill)
Hotshot
20 Year Member
Joined: Jul 2005
Posts: 11,932
Likes: 181
Your on the right track... I know with the BIG motor I was working on, they just pulled a couple 3/4 inch pipe plugs on the manifold / block and routed to the heater. No heat but I didn't know why. I put a tygon clear hose on one side so I could see the flow--- NONE. Then noted that both hoses were basically tied to the same part of the system... moved one closer to the pump discharge hose and put the other closer to the radiator bottom hose (suction to the pump).......... electric pump is also an idea.
 
Reply
Old Jan 27, 2015 | 08:17 PM
  #5  
brobrad's Avatar
brobrad
Thread Starter
|
Senior User
Joined: Oct 2011
Posts: 485
Likes: 1
Originally Posted by steve(ill)
Your on the right track... I know with the BIG motor I was working on, they just pulled a couple 3/4 inch pipe plugs on the manifold / block and routed to the heater. No heat but I didn't know why. I put a tygon clear hose on one side so I could see the flow--- NONE. Then noted that both hoses were basically tied to the same part of the system... moved one closer to the pump discharge hose and put the other closer to the radiator bottom hose (suction to the pump).......... electric pump is also an idea.


I just re-plumbed it all in the original configuration. I'm getting flow, but not quite enough to get heat to my wvo early enough. I ordered an electric coolant pump I can use in the colder months at start up to get the WVO warm sooner. If heats up quick when running it down the road, so the pump will just facilitate that quicker.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Greywolf
1997 - 2003 F150
17
Dec 4, 2014 07:36 PM
silan
Aerostar
13
Dec 4, 2006 04:40 AM
Baggins
Aerostar
10
Dec 22, 2005 02:12 PM
droff150
1987 - 1996 F150 & Larger F-Series Trucks
7
Dec 22, 2004 03:21 AM
77lowrider
1973 - 1979 F-100 & Larger F-Series Trucks
5
Mar 11, 2004 04:09 PM




All times are GMT -5. The time now is 06:35 PM.

story-0
10 Ways Ford is LOSING to the Competition

Slideshow: 10 ways Ford is losing to the competition

By Joe Kucinski | 2026-06-15 09:52:01


VIEW MORE
story-1
Top 6 Best Deals Available on New Fords & Lincolns Right Now

Some great targets in today's expensive world.

By Brett Foote | 2026-06-15 09:35:19


VIEW MORE
story-2
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

Slideshow: The VelociRaptor Expedition gains a lift, upgraded suspension, Brembo brakes, and trail-ready equipment while retaining the stock 440-horsepower EcoBoost V6.

By Verdad Gallardo | 2026-06-12 11:01:55


VIEW MORE
story-3
Top 10 Fords at 2026 Carlisle Ford Nationals

Slideshow: Top 10 Fords at 2026 Ford Nationals

By Joe Kucinski | 2026-06-09 11:10:08


VIEW MORE
story-4
3 Best / 3 Worst Parts of Modern Ford Ownership

Based on years of owning multiple modern Ford products.

By Brett Foote | 2026-06-09 10:53:36


VIEW MORE
story-5
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

SPONSORED: From muddy boots to rain-soaked cargo, these upgrades address some of the most common frustrations Ford truck owners face every day.

By Pouria Savadkouei | 2026-06-08 18:50:34


VIEW MORE
story-6
Every 2026 Ford Engine Explained

Here's everything you need to know about every Ford engine available for the 2026 model year.

By Brett Foote | 2026-06-05 12:58:01


VIEW MORE
story-7
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-8
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 15:43:58


VIEW MORE
story-9
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-06-03 11:38:36


VIEW MORE