Skip the auto shop - Our mechanics make house calls

Q: My truck surges at low and idol speeds. Cold or hot. Sometimes quits when put in gear. Very low speed has a miss.

asked by on

I have replaced most sensors and ignition components . Check engine light is not on. If I unplug temp sending unit , service engine light comes on and vehicle stops surging . I've rebuilt throttle body and replaced both injectors . I've changed tps, iac, map, egr , plugs, wires distributer . Also checked for vacuum leaks everywhere that I know to check .

My car has 180000 miles.
My car has an automatic transmission.

Hello and thank you for contacting YouMechanic. When you unplug the temperature sending unit the problem goes away but the engine light comes on. Check the plug to the sending unit for any corrosion or debris. Look at the pins to the temperature sending unit and make sure that they are not bent or broken. If the sending unit and harness looks fine then you would need to replace the unit.

I recommend replacing the temperature sending unit and then running the engine. If you need help with diagnosing your Check Engine Light and rough running symptoms, then contact a professional, such as one from YourMechanic. One of our mobile technicians can come to your home to assist you with the necessary repairs.

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. My truck surges at low and idol speeds. Cold or hot. Sometimes quits when put in gear. Very low speed has a miss.

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: Power window not working.

If the motor is getting power from the switch and still not moving, the problem is the motor / regulator. If no power is received from the switch when pressing, the problem is the switch. Make sure the fuse is not blown,...

Q: Took my car through inspection and it passed. Did emissions and I was told that I need to replace the muffler catylic converter and o2 sensor. Is this true?

Hi there. From the description you have provided, your vehicle passed inspection but failed emissions, this would lead me to believe the Check Engine Light is on. Knowing the code(s) could help with diagnoses. A plugged catalytic converter(s) could prevent...

Q: Car is having temperature issues - 2003 Nissan Altima

Hi there. From the description you have given, your vehicle's heater not working is not the only problem that needs to be addressed. Chances are the sealer could have plugged the heater core. A cooling system flush could correct the...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
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...
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...