Go Back   Ford Truck Enthusiasts Forums > Newer Light Duty Trucks > 2004 - 2008 F150
Sign in using an external account
Register Forgot Password?


2004 - 2008 F150 2004, 2005, 2006, 2007 and 2008 Ford F150's with 5.4 V8, 4.6 V8 or 4.2 V6 engine
SPONSORED BY:
Click HereAdvertisement

Welcome to Ford-Trucks Forums!
Welcome to Ford-Trucks.com.

You are currently viewing our forums as a guest, which gives you limited access to view most discussions and access our other features. By joining our community 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 fast, simple and absolutely free so please, join the Ford-Trucks Forums community today!





 
Reply
 
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 05-04-2014, 10:58 PM
bigcountry25 bigcountry25 is offline
New User
 
Join Date: Oct 2013
Posts: 13
bigcountry25 is starting off with a positive reputation.
07 4.2l spark knocking is driving me insane!!!

I have an 07 4.2L 5 speed and the spark/labor knock is really driving me insane! I had a Ranger years ago that done the same thing from the time I got it with 40,000 miles and was never able to fix it and when I got rid of it with 220,000 miles it was still spark knocking but running strong. But I think neither should do it.

Here is what it does Under heavy acceleration I have spark knocking and also when I am holding 55-65mph on the HWY the spark knock is really excessive. If have have the cruise set at HWY speeds it is the same thing and if I am climbing an incline it is really bad.

I have no codes pending or otherwise and no check engine light on.

I have tried 93 octane 100% gas with no ethanol and it makes no difference.

I replaced the plugs with Motorcraft OEM replacement and it didn't change. Changed the plug wires put a K&N air filter on and replaced the plugs again but this time used Bosch Platinum +4 and still no change. I also cleaned the MAF sensor.

Other than the spark knock it runs pretty good other than a little bit of a rough idle.

So I am looking for some input on what to check or try changing next.

Also was there a TSB for the 2007 4.2L about spark knocking. I ran across some posts about a 4.2 TSB about spark knocking but I don't think it included my model year.

Thanks
Reply With Quote
  #2  
Old 05-05-2014, 07:20 PM
1saxman's Avatar
1saxman 1saxman is offline
Elder User
 
Join Date: Jan 2007
Posts: 519
1saxman is starting off with a positive reputation.
Its only caused by a couple things. Too much spark advance or excessive carbon in the combustion chambers that glows and causes pre-ignition. I think maybe its carbonned-up which also has the effect of raising the compression ratio. I would start right away using premium gas along with fuel system/injector cleaner in every tank of gas from now on. If this starts to work and the pinging stops, you can drop down to mid-grade and continue the program, finally getting back to regular. At that time I would suggest using a fuel stabilizer/cleaner every time you get gas. The 4.2L in the truck runs rich and you can expect carbon trouble if you don't regularly use an additive.
__________________
2007 F-150 V6 5-Speed Manual
Reply With Quote
  #3  
Old 05-05-2014, 09:21 PM
bigcountry25 bigcountry25 is offline
New User
 
Join Date: Oct 2013
Posts: 13
bigcountry25 is starting off with a positive reputation.
I have stated running 93 octane that is 100% gas with no ethanol.

What additive do you suggest I use for the carbon build up.

I have been told to take the K&N filter off and go back to the stock filter and there reasoning was it would cause more gas in the fuel to airflow mixture??? What do you think about this?

Thanks
Reply With Quote
  #4  
Old 05-06-2014, 12:14 PM
1saxman's Avatar
1saxman 1saxman is offline
Elder User
 
Join Date: Jan 2007
Posts: 519
1saxman is starting off with a positive reputation.
The low-restriction air filter simply allows more air to pass thru it. The electronic fuel injection system therefore is forced to add more fuel to the air because the MAF sensor is calling for it. The overall ratio of fuel to air is therefore the same - there is simply more fuel/air mixture to burn. The oil treatment on K&N-type low-restriction filters has been known to collect on the wires of the MAF sensor, causing a malfunction. For that reason only, I would suggest using a stock filter at least until you solve the pre-ignition problem.
You'll probably have to use a strong cleaner to reduce the carbon, then a maintenance additive to prevent it from re-forming. For the maintenance additive, I use Sta-Bil for Ethanol fuels, my favorite being the super-concentrated blue which is used at 1 oz to ten gallons. I haven't had to use anything stronger because I haven't had the problem you are experiencing. You might try Seafoam How to use SeaFoam to clean your Engine - The RIGHT way! which is safe and won't harm anything. You really should do the 'injection' method which is explained in the linked article, but I probably would just use it in the fuel where it works all the time. All this is assuming the carbon is actually the problem. It could also be a fault in the engine controls by allowing too much spark advance. In the old days we would get out the timing light and check the timing and adjust it at the distributor. I guess now they have to hook it up and do a diagnostic. Dealers and other shops now also do injection cleaning which is probably a good idea since you're having a severe problem.
Premium fuel is good for this on a temporary basis because it reduces 'ping' and also has more cleaners. I would keep using it and put in a can of Sea-Foam with each fill of 15 gallons or more.
If it doesn't get any better in the first few weeks, you probably should have the diagnostic done to see if there are any control or sensor problems. Most engines have a 'knock sensor' that could go bad and fail to send the signal to retard timing to prevent knock.
__________________
2007 F-150 V6 5-Speed Manual
Reply With Quote
Old 05-06-2014, 12:14 PM
 
 
 
Reply

Go Back   Ford Truck Enthusiasts Forums > Newer Light Duty Trucks > 2004 - 2008 F150

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
07 I have a miss at idle I can't get rid of..need some help!! bigcountry25 2004 - 2008 F150 2 08-21-2014 09:46 AM
Crappy gas mileage 4.2L 2007 Help!!!! bigcountry25 3.8 & 4.2L V6 4 07-11-2014 08:20 PM
94 f150 spark knock, rough idle timbramo Ford Inline Six, 200, 250, 4.9L / 300 17 11-12-2013 07:39 PM
MPG Low 4.2L 5 Speed also dies easy on take off bigcountry25 2004 - 2008 F150 3 10-26-2013 07:33 PM
spark knock, rough idle timbramo 1987 - 1996 F150 & Larger F-Series Trucks 0 10-15-2013 03:32 PM



All times are GMT -5. The time now is 05:43 AM.


Powered by vBulletin® Version 3.8.7 AC1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Advertising - Terms of Use - Privacy Statement - Jobs
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. FordŽ is a registered trademark of the Ford Motor Company.

vbulletin Admin Backup