Skip the auto shop - Our mechanics make house calls

Q: Truck suddenly has no power, won't rev above 4K, and idles fine.

asked by on

My truck suddenly has no power - top speed maybe 65 mph, slows to 45 or 50 up moderate hills even if I downshift. It idles ok and at low throttle positions and RPM seems normal but still underpowered. Above 3500 rpm it has a rattle, and seems to miss and buck a bit - had the check engine light flashing uphill. Won't rev over 4K with any load at all. Took it in and the shop had it 2 weeks, couldnt find anything for sure but said they thought the exhaust was plugged. Exhaust seems to blow out fine, but could the cats be plugged? Something in the valvetrain bent or broken? Don't think it's fuel delivery as it would still be smooth. Thoughts?

My car has 160000 miles.
My car has a manual transmission.

Hello there, many faults will cause a lack of power on your 2003 Ford F-150. The most common would be a failed catalytic converter, throttle body plate malfunction, vacuum leak, throttle linkage, fuel pump, or a shift solenoid. When the Check Engine Light flashes this is an indication that something may be damaging the catalytic converter. To avoid any unnecessary repairs, a qualified technician, such as one from YourMechanic, will be able to diagnose your loss of power on site at your own location.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. Truck suddenly has no power, won't rev above 4K, and idles fine.

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: I have a 2003 Ford F350 Super Cab dually, rear wheel drive. I am trying to replace the front rotors, but cannot get the old rotor

Your issue is a tough one to give guidance on. If you have researched you have probably heard anything and everything I have to tell you. The only option I see that you may have not tried is chemical solvents....

Q: I got my car inspected it failed they gave me a price i want to make sure its not over priced

You would need to give more detail of what work would be performed and parts provided for the $1500. You also did not state what was the cause of the vehicle failing the car inspection. If you supply this information...

Q: Rough Idle

Since the check engine light came on you will want to have a computer scan for stored codes. This may indicate the cylinder that is misfiring or having issues and then further diagnosis on that cylinder can be done to...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.