Go Back   Ford F150 Forum - Community of Ford Truck Fans > Late Model F150s > Engine / Drivetrain Talk > 8 Cylinder Engines
Sign in using an external account
Register Forgot Password?
Register Garage Photos FAQ Members List Social Groups Calendar Search Today's Posts Mark Forums Read StoreVendor Directory

Welcome to F150 Forum!
Welcome to F150 Forum,

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!


Reply
 
 
 
 
Thread Tools Search this Thread Display Modes
Old 03-12-2012, 10:10 AM   #1
Junior Member
 
cbholt's Avatar
 
Join Date: Mar 2012
Posts: 12
Mentioned: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Default 1997 4.6 Spark Knock Issue

The vehicle is a 1997 F150 4.6 Auto 4X4. At highway speeds, it wants to spark knock pretty consistently when the engine is under a load. Third gear climbing hills is the worst, and even overdrive cruising up moderate hills is bad too. It seems to only want to do it over 2300 RPMS. I am getting good fuel mileage, well, normal fuel mileage. I haven't seemed to have lost any power. When I use premium fuel it seems to help quite a bit. I have heard that 3 probable causes are knock sensor, mass air flow sensor, or carboned up engine. I have tested the Mass Airflow Sensor with a multimeter and it tested perfect. I have been running injector cleaner such as Seafoam and Techron quite a bit lately, so I don't think its a dirty engine. I have been told that the knock sensor is located in the middle of the valley, under the intake manifold. What else could it be? I want to rule out all I can before I take the top of the engine apart. I have no check engine light and no trouble codes.
cbholt is offline   Reply With Quote
Old 03-19-2012, 09:21 PM   #2
Junior Member
 
cbholt's Avatar
 
Join Date: Mar 2012
Posts: 12
Mentioned: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Default

Nothing at all?
cbholt is offline   Reply With Quote
Old 04-19-2012, 08:36 AM   #3
new guy
 
Join Date: Mar 2012
Location: South Jersey
Posts: 111
Mentioned: 0 Post(s)
Thanks: 0
Thanked 3 Times in 3 Posts
Feedback Score: 0 reviews
Default

I have the same problem with my 05 5.4
razzle is offline   Reply With Quote
Old 05-07-2012, 11:23 PM   #4
Member
 
glw165's Avatar
 
Join Date: May 2011
Posts: 69
Mentioned: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Default

mine was horrible spent alot cash plugs wires fuel filter, maf cleaner, i finally took maf off my other f150 and that completely fixed mine, i cant make it s/k anymore
glw165 is offline   Reply With Quote
Old 05-08-2012, 09:50 AM   #5
new guy
 
Join Date: Mar 2012
Location: South Jersey
Posts: 111
Mentioned: 0 Post(s)
Thanks: 0
Thanked 3 Times in 3 Posts
Feedback Score: 0 reviews
Default

i cleaned my maf senser. truck runs better but mine only knocks going up hills so im waiting to see how it is in the hills.
razzle is offline   Reply With Quote
Old 05-09-2012, 02:07 PM   #6
Junior Member
 
cbholt's Avatar
 
Join Date: Mar 2012
Posts: 12
Mentioned: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Default

I finally took the truck to Ford to have them try to fix it. They cleaned the maf sensor(which I already have done), and they reflashed the computer($238 total). It helped quite a bit, but didn't totally stop the pinging. The only time it pings now is when your in 3 gear (auto) and climbing a big hill going 65+ mph. I can pretty much tolerate that amount of pinging. The truck climbs hills in overdrive fairly well, so it shouldn't be too much of an issue. Hopefully it doesn't go back to its old ways eventually.
cbholt is offline   Reply With Quote
Old 05-10-2012, 08:45 AM   #7
new guy
 
Join Date: Mar 2012
Location: South Jersey
Posts: 111
Mentioned: 0 Post(s)
Thanks: 0
Thanked 3 Times in 3 Posts
Feedback Score: 0 reviews
Default

Im thinking about getting a programmer. Maybe that would help with the lean ping.
razzle is offline   Reply With Quote
Old 10-06-2012, 07:34 AM   #8
Senior Member
 
plumberboy's Avatar
 
Join Date: Nov 2009
Location: PA
Posts: 134
Mentioned: 0 Post(s)
Thanks: 2
Thanked 1 Time in 1 Post
Feedback Score: 0 reviews
Default

I have the same issue now. I posted a bunch of times on my header change...everything else is resolved. Now I am down to the knocking while speeding up while going up hills.
Do you have anymore to add to the thread? All suggestions are appreciated.
plumberboy is offline   Reply With Quote
Old 10-08-2012, 12:11 PM   #9
Junior Member
 
cbholt's Avatar
 
Join Date: Mar 2012
Posts: 12
Mentioned: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Default

Well the truck slowly went back to its old ways. I have been pulling the appropriate fuse to reset the KAM about once a month. I have been putting premium in it when I pull a trailer and that stops all pinging. Still pings when in 3rd gear above 2500 rpm on 87octane. May return to ford eventually.
cbholt is offline   Reply With Quote
Old 10-09-2012, 06:20 PM   #10
Senior Member
 
plumberboy's Avatar
 
Join Date: Nov 2009
Location: PA
Posts: 134
Mentioned: 0 Post(s)
Thanks: 2
Thanked 1 Time in 1 Post
Feedback Score: 0 reviews
Default

I found a vacuum leak. I hate to say that I am not sure what it is called. Its the black tube that is in the shape of a 45 deg bend. It is the same size as a 3/4" heater hose. On the 4.6 it goes from a black box to an inlet right by the idle air control. Replacing that got rid of the pinging that was really bad going up hills. But I still have that knock like yours. I have heard sea foam is something to try if you think its from a carbonbuild up. I have plans to try that before the knock sensor replacement.
Thanks for keeping this up to date.
plumberboy is offline   Reply With Quote
Old 10-09-2012, 06:20 PM
 
 
 
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


 

The Mustang Source

All times are GMT -4. The time now is 10:03 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.5.2
Copyright 2006 - 20011 F150forum.com
This site is in no way affiliated with the Ford Motor Company.


Garage Plus vBulletin Plugins by Drive Thru Online, Inc.