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 1,000 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
  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: Car feels like it may stall, in Drive

Hi Jill. Thanks for contacting us today. I'm assuming that you meant to type 600 RPM instead of 6000, but if this is the case, then there are a few possible non-recall specific reasons this can happen. In most cases,...

Q: How do I check my transmission fuild and where is it located ?cant seem to find it

Great question. Some newer cars don't allow you to check your transmission fluid. If your car has one, the transmission dipstick should be somewhere close to the transmission or coming from the transmission. The dipstick will more than likely have...

Q: My car won't start and the check engine light and check oil lights are on

The clicking sound can occur when there is not enough battery power getting to the starter to crank the engine. If the cables were corroded, then the battery may be sulfated and need to be replaced. A simple battery check...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.