Notices
1997 - 2006 Expedition & Navigator 1997 - 2002 and 2003 - 2006 Ford Expedition and Lincoln Navigator Discussion

03 navigator engine coolant temperature problem

Thread Tools
 
Search this Thread
 
Old Dec 18, 2012 | 12:54 AM
  #1  
charlie90262's Avatar
charlie90262
Thread Starter
|
New User
Joined: Jan 2011
Posts: 4
Likes: 0
From: south gate
03 navigator engine coolant temperature problem

hello fellow members this is my 1st post and in need of help i have a 03 navigator 5.4 3v im getting a check engine light code p0117 i changed thermostat and 2 sensors one in back of pass hed and the other one next to the themostat . cooling gauge goes half way and then it just dies auto zone gave me this sensor part number # SU8781 its lite brown with 2 wire clip i been looking and just cant find nothing thx for ur help in advance
 
Reply
Old Dec 18, 2012 | 01:25 PM
  #2  
pdqford's Avatar
pdqford
Logistics Pro
20 Year Member
Liked
Loved
Joined: Jan 2001
Posts: 3,740
Likes: 37
From: Central NYS
Originally Posted by charlie90262
im getting a check engine light code p0117 i changed thermostat
I'm not sure changing the thermostat will fix your check engine light. The P0117 is the computers way of telling you that the voltage on the ECT (Engine Coolant Temperature) sensor circuit was too low (i.e, less than 0.2V) for normal operation. That would indicate a temp of over 250 degrees F. Did your Navigator overheat at some time?

Originally Posted by charlie90262
i changed thermostat and 2 sensors one in back of pass hed and the other one next to the themostat .
Sounds like you changed both the CHT (Cylinder Head Temperature) sensor as well as the ECT (Engine Coolant Temperture) sensor.

Originally Posted by charlie90262
cooling gauge goes half way and then it just dies
Could you elaborate on what you mean that it 'just dies'?

Originally Posted by charlie90262
auto zone gave me this sensor part number # SU8781 its lite brown with 2 wire clip
Did auto zone say what kind of a sensor it was?
 
Reply
Old Dec 18, 2012 | 01:37 PM
  #3  
khadma's Avatar
khadma
Carpenter Local 745
15 Year Member
Photogenic
Photoriffic
Joined: Apr 2006
Posts: 5,794
Likes: 11
From: on da beach
Club FTE Silver Member

AZ
Duralast/Oil Temperature Switch (SU8781) | AutoZone.com

What was the other switch's part number?

Also, did you disconnect the negative battery cable before

Replacing switches/sensors?
 
Reply
Old Dec 18, 2012 | 11:56 PM
  #4  
charlie90262's Avatar
charlie90262
Thread Starter
|
New User
Joined: Jan 2011
Posts: 4
Likes: 0
From: south gate
the needle for the temp goes half ways and just dies goes down and i get check engine light on with the coolant light on and code p0117
 
Reply
Old Dec 18, 2012 | 11:59 PM
  #5  
charlie90262's Avatar
charlie90262
Thread Starter
|
New User
Joined: Jan 2011
Posts: 4
Likes: 0
From: south gate
http://www.autozone.com/autozone/par...631220_0_18589_
 
Reply
Old Dec 19, 2012 | 12:01 AM
  #6  
charlie90262's Avatar
charlie90262
Thread Starter
|
New User
Joined: Jan 2011
Posts: 4
Likes: 0
From: south gate
thats the sensor they gave me and from what i heard from my friend that coolant sensor goes inside the oil pan and from what i been googling the cooling sensor 2 wire harnest gets messt up thx guy for all ur help
 
Reply
Old Dec 19, 2012 | 09:53 AM
  #7  
pdqford's Avatar
pdqford
Logistics Pro
20 Year Member
Liked
Loved
Joined: Jan 2001
Posts: 3,740
Likes: 37
From: Central NYS
Originally Posted by charlie90262
i have a 03 navigator 5.4 3v
Are you sure its a 3-valve engine? What is the eighth digit of the VIN?
 
Reply
Old Dec 19, 2012 | 10:49 AM
  #8  
pdqford's Avatar
pdqford
Logistics Pro
20 Year Member
Liked
Loved
Joined: Jan 2001
Posts: 3,740
Likes: 37
From: Central NYS
Originally Posted by charlie90262
i heard from my friend that coolant sensor goes inside the oil pan
How is the coolant sensor going to sense the coolant temp if the sensor is located in the oil pan
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

 Verdad Gallardo
story-1

Top 10 Fords at 2026 Carlisle Ford Nationals

 Joe Kucinski
story-2

3 Best / 3 Worst Parts of Modern Ford Ownership

 Brett Foote
story-3

10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

 Pouria Savadkouei
story-4

Every 2026 Ford Engine Explained

 Brett Foote
story-5

10 Ugly Ford Trucks That We Still Kinda Love

 Joe Kucinski
story-6

10 Things Every Truck Owner NEEDS (2026 Edition)

 Michael S. Palmer
story-7

Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

 Verdad Gallardo
story-8

Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

 Joe Kucinski
story-9

2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

 Brett Foote
Old Dec 19, 2012 | 11:18 AM
  #9  
pdqford's Avatar
pdqford
Logistics Pro
20 Year Member
Liked
Loved
Joined: Jan 2001
Posts: 3,740
Likes: 37
From: Central NYS
Originally Posted by charlie90262
the needle for the temp goes half ways and just dies goes down and i get check engine light on with the coolant light on and code p0117
Sounds to me then that the PCM is indicating that it is not receiving a valid voltage from the ECT sensor. Normally the PCM sends coolant information over the SCP (Standard Corporate Protocol) network and would be picked up by the HEC (Hybrid Electronic Cluster, aka Instrument Cluster), processor. If the HEC doesn't receive coolant info every so many seconds from the PCM, it doesn't know where to command the temp gauge needle to point.

The Navigator runs three different networks to support communication between the various electronic modules. All three networks are accessable through the DLC. I think your gonna need a scan tool that can read U codes to see if you are having an issue with network communications and/or run a self test on the HEC to see if it is having issues controling the virtual temp gauge.

I'm afraid that this is beyond my pay grade
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
homertwo
1999 - 2003 7.3L Power Stroke Diesel
5
Jan 23, 2019 08:45 AM
hood
Modular V8 (4.6L, 5.4L)
4
Jan 27, 2015 05:49 AM
john19999
1997 - 2006 Expedition & Navigator
10
Nov 21, 2010 08:26 AM
Heavenword1
Explorer, Sport Trac, Mountaineer & Aviator
10
Dec 5, 2007 05:23 PM
78_351M
1999 - 2016 Super Duty
3
Sep 22, 2004 08:41 PM




All times are GMT -5. The time now is 12:19 AM.

story-0
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-1
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-2
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-3
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-4
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-5
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-6
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-7
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
story-8
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-9
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE