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Ask A. Penland Your Own Question
A. Penland
A. Penland, Ford Senior Master Technician, ASE
Category: Ford
Satisfied Customers: 6593
Experience:  ASE Master Certified, ASE Advanced Gasoline Engine Performance
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I have loss of power and sluggish run at all speeds/rpms.

Customer Question

I have loss of power and sluggish run at all speeds/rpms.
JA: What is the make/model/year of your car?
Customer: 2004 f150 fx4 5.4 motor just had new exhaust from manifolds, new cats, muffler, and tail pipes there was a small exhaust leak on passenger side manifold that is why I replaced everything there is 217000 miles and plugs and coils were replaced a second time at 197000
JA: How many miles are on the car? How has your MPG been lately?
Customer: mpg has always been bad 12-15 since new. that is horrible but is what it is
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: entire new exhaust system with new o2 sensors no codes. my mechanic could not find codes either there has been a knocking tapping sound since it had 2000 mi dealer said it was normal. It has gotten louder over the years but never has affected the performance
JA: Anything else you want the mechanic to know before I connect you?
Customer: no
Submitted: 9 months ago.
Category: Ford
Expert:  A. Penland replied 9 months ago.

Can you give me the VIN# ***** the F150?
Have you had the engine computer scanned for any trouble codes?

Customer: replied 9 months ago.
No codes found
Customer: replied 9 months ago.
Expert:  A. Penland replied 9 months ago.

Where is the knocking noise coming from?
The front of the engine at the top?

Customer: replied 9 months ago.
I think it is one of the lifters. Noise has been there since 2000 mi
Expert:  A. Penland replied 9 months ago.

You will need to remove the valve covers and inspect each follower (rocker arm) to see if they are loose. You do not have to remove them, just look at the closely and inspect the camshaft lobes for wear.