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Chris (aka- Moose)
Chris (aka- Moose), Technician
Category: Ford
Satisfied Customers: 45554
Experience:  16 years experience
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2004 5.4, no codes, pings under load, fuel rail pressure is

Customer Question

2004 5.4, no codes, pings under load, fuel rail pressure is nearly constant at 40psi, desired fuel pressure varies and increases with load demand. Fuel Pump Control Module issue?
JA: Thanks. Can you give me any more details about your issue?
Customer: Running premium fuel, fuel mileage is down some, low end power seems to be ok, but fades with higher rpm. starts good, idles good, seems to drive ok if I don't have to jump on it. No apparent vacuum leaks, no change in performance between 2W and 4W drive.
JA: OK got it. Last thing — Ford Mechanics generally expect a deposit of about $28 to help with your type of question (you only pay if satisfied). Now I'm going to take you to a page to place a secure deposit with JustAnswer. Don't worry, this chat is saved. After that, we will finish helping you.
Submitted: 1 year ago.
Category: Ford
Expert:  Chris (aka- Moose) replied 1 year ago.

Welcome, I'm Chris (aka Moose). Experts aren't employees / agents of Just Answer. We are independent service providers using the Site to sell their Expert knowledge to Customers. I strive to provide EXCELLENT 5 STAR service, let me know what's needed from me so your pleased.

Are you sure its a ping spark knock and not a rattle noise from a valve train concern?

Did 93 octane make any difference at all?

Customer: replied 1 year ago.
Hi, fuel grade made no difference. I checked the MAF sensor and it's pretty good compared to other's I have worked on. Capped the PVC and test drove it, no change. It's deffinately pinging. Slight change in throttle position can make it ping or not. I put a vacuum gauge on it, a solid 19". I have an Edge tuning kit on it, but I have taken it back to stock except for the transmission shift mod. I start it in the morning and let it idle for about 10 min before I get on the road. Then it's mostly highway driving for 20 min. It has to be ready for highway speed as soon as I leave. I just put 2 cans of Seafoam in the tank. That has helped a lot with other Fords that I have had performance issues with. I can't afford to spend a lot of money on try this or try that and maybe...
Expert:  Chris (aka- Moose) replied 1 year ago.

Thanks, ***** ***** spark knock, the fuel is igniting from heat and compression prior to the spark plug igniting the fuel. Running lean, carbon buildup, and high head temps can cause this. Remove a vacuum line from the intake as close to the throttle body as possible. Run the engine at 2000 rpms while someone slowly pours a can of sea foam into this vacuum line to fog the intake and cylinders to remove carbon buildup. Remove the thermostat and drain the coolant. Reinstall the thermostat housing without the thermostat and perform a flush on the cooling system. Install a new thermostat and new coolant. Try these things to see if they help.

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Customer: replied 1 year ago.
It pings cold or hot. Head temp runs between 185 and 190
Expert:  Chris (aka- Moose) replied 1 year ago.

Since it occurs cold, that indicates incorrect spark plugs in use, though it extremely rare to get spark knock (ping) on a cold engine. It is looking more like a valve train noise.

Expert:  Chris (aka- Moose) replied 1 year ago.

I like to stay in contact with my customers that appear not pleased, still working on the concern, or have not rated yet. I assume you were not pleased with my help. I hate that you have spent money to get an answer but left not happy. Can you tell me why, or can I help more. If its more help you need just reply and we can pick up where we left off. I am also sending an offer allowing me to upload diagrams or repair guides if that helps.

Thanks Chris