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Ask Chris (aka- Moose) Your Own Question
Chris (aka- Moose)
Chris (aka- Moose), Technician
Category: Ford
Satisfied Customers: 47678
Experience:  16 years experience
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F350 super duty: Solve my knock and power loss v10

Customer Question

Solve my knock and power loss for 1999 v10 F350 4x4 manual trans. Idle air control test phases, no codes present. Knock is at or above 2500rpm. Worst knock or rather pinging is with just a touch of throttle. Giving it more gas Eliminates ping. Vacuum tube under throttle body was replace 2yrs ago and is not leaking now.
Submitted: 2 years ago.
Category: Ford
Expert:  fordtechsuzukitech25 replied 2 years ago.
first thing i would do is check fuel pressure, normally a ping is from lack of fuel
Customer: replied 2 years ago.
That's funny. Pressure is fine. pings when hot more power when it is cold ( first 30 min on freeway). I suspect vacuum leak with heat or some gunk in throttle valve or exhaust issue : oxygen sensors or Pcm. 102,000 miles total, air cleaner is fine, fuel filer is new. Have throttle valve gaskets arriving mañana so I can remove and clean completely. What is the test for mass air flow?
Expert:  Chris (aka- Moose) replied 2 years ago.
Hello, I'm Chris. Thanks for seeking us for help.
Pinging is a result of the fuel igniting prior to the spark plugs lighting up. This that can cause this are:
High cylinder head temps and cooling system issues
Carbon buildup in the combustion chamber
Running lean
Incorrect spark plugs
Have you tried to check or address any of these?
You want a excellent 5 star answer & I would like to be rated the same for providing it. Consider I don't know your skill level & I can't see, smell, hear, or touch the vehicle. It may take a few back and forth replies. Try your best to respond with good detail so I can do the same. I normally log in at 3pm and work late. A rating is required. Your rating me, what I type. I am not an employee of this website, nor have control over the fees or the time it took to get a response. If you rate negative or not at all you still paid, but I get nothing. I want you pleased with me and my efforts, so let me know if your experience here has come up short.
Thanks Chris
Expert:  Chris (aka- Moose) replied 2 years ago.
Any more help needed?
Customer: replied 2 years ago.
Ok. Thanks. But what can I do to fix the issue. How can I tell if it is running too lean? Do spark plugs last more than 100kmi? How do I clean the carbon deposits? How do I confirm any of your potential root causes?Many thanks
Expert:  Chris (aka- Moose) replied 2 years ago.
If its running lean there will be lean codes store P0171 and P0174 and the fuel trims will be out of the +/- 10 limits. Spark plugs last about 70,000 miles if there motorcraft.Follow the directions on the sea foam website to fog the intake and clean the carbon out.With no warning lights or scan tool readings or temp monitoring and me not knowing the prior maintenance history I can not confirm which repair is needed or which is going to be the resolve. I can just tell you what can be to blame and what steps to address them.