Q: 1- Jerk at highway speeds and coolant guage goes crazy when this happens. 2-Truck starts accelerating randomly when idleing.

asked by on

When I drive on the highway I experience a jerk that is not a transmission jerk but more like a miss or loss of fuel. When this happens my coolant gauge goes all over the place. Turning off and on as the problem happens. Another problem that started happening at the same time is my truck accelerating when I am idling.

My car has 270000 miles.
My car has an automatic transmission.

Hi There, It sounds like you may have a couple of different issues. The jerking reaction and random acceleration problem is likely related to a dirty or faulty mass air flow sensor. The mass air flow sensor monitors air intake as it is mixed with fuel prior to being injected into the motor. This sensor relays vital information to the ECM which uses this to make adjustments to fuel supply to the motor. A dirty or faulty sensor can cause an imbalanced air/fuel load to be supplied to the motor which results in an over fueling or under fueling situation depending on the conditions. This type of inconsistent fuel supply to the motor may cause a hesitation, loss of power, a jerking reaction, potentially a bit of black exhaust smoke and typically a strong smell of fuel when this sensor is malfunctioning.

The erratic fluctuation of the temperature gauge may suggest you have a bad coolant temperature sensor, which may also be contributing to the random acceleration and missing reaction. When the coolant temperature sensor is not working properly, this can cause the computer to make inaccurate fueling adjustments to enrich or lean out the fuel supply depending on temperature. I would suggest having a professional from Your Mechanic come to your home to diagnose and inspect your vehicle.

Was this answer helpful?
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. 1- Jerk at highway speeds and coolant guage goes crazy when this happens. 2-Truck starts accelerating randomly when idleing.

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: Q: My car won't start after cold weather

The most likely cause for this is that the battery went bad, especially if it is more than about three years old. Some cheap batteries are only good for a couple of years. Have the battery and charging system checked...

Q: One article I read said it could be a fuse which fuses would it be

Hi There, This should be a 10 amp fuse that operates the radio and clock. The other possibility that may cause this could be your ignition key tumbler that may be causing the key to get stuck as the tumblers...

Q: Q: Seat belt not working.

More than likely the buckle needs to be replaced. It's unsafe and illegal to drive without a seatbelt, so I suggest you get this fixed as soon as possible. Any qualified mechanical, like one from YourMechanic, can handle this task...

Related articles

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...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...