Determine Why a Car Stalls at Intersections

There may be lots of reasons a car stalls at intersections, including low automatic transmission fluid levels, moisture in your gas, broken sensors, or issues with the EGR valve.

Steps

Low Transmission Fluid Level

  1. Check the dipstick on the automatic transmission. Check the owner's manual for the correct procedure for your vehicle — generally, manufacturers prefer testing with a warm engine.
    • Be sure to check the fluid when parked on a level surface. Do your best to not allow any lint or dirt to contaminate the dip stick before reinserting.

Clogged Catalytic Converter

  1. Look for stalling, no power when accelerating. The check engine light will likely be on.
  2. Look under the car at night after the vehicle has been running for a while. If the catalytic converter is glowing, it's probably clogged. You will have to replace the converter if you find this to be the problem.

Broken O2 Sensors

  1. Look for initial idle OK after a cold engine start-up, but a warm engine idle will surge and stall.
  2. Take your car in to get a reading. After a few thousand miles of this, most cars will turn on the "check engine" light. You can take it to any AutoZone, Advance auto parts, Napa, or O'Reilly's (but some places may only check cars made after 1996, so call and check first) and they will read the codes for free. There can be any number of reasons for the "check engine" light to come on, so it is good to check. Codes complaining of unexpected lean mixture is a good indication of O2 sensor failure. O2 sensors will typically last 60–75K miles. The good news is that you can buy an O2 sensor on-line for around $50 and they are generally pretty easy to replace. Another possible reason is that the engine is idling too low (the idle is adjustable) or the control module is going out, which is relatively inexpensive and easy to access and fix.

Clogged/Stuck EGR Valve

  1. Look for the Engine Code Error (EGE) P1406. If the EGR valve is stuck open, the car will run sluggish at lower RPMs. If the valve is stuck closed, the car won't run well at higher RPMs (on the highway).
  2. Try cleaning the excess carbon out of the EGR valve first. It may just need to be cleaned and not need replacing. If cleaning the EGR valve does not work and you are still getting code P1406, the EGR valve needs to be replaced.

Tips

  • In vehicles with automatic transmissions that sometimes have a problem with stalling at lights or stop signs, most of the time it is a difference in pressure on each side of the pressure plate. A loss of pressure on one side or another will cause a stall. When you have low transmission fluid and come to a stop, most of the fluid travels to the front of the transmission and you get a difference in pressure that causes your car to stall. Check your transmission fluid.
  • If you have to check the fluid with the car running, make sure to set the parking brake. Most cars will ask you to put the car in Park or Neutral. Make sure you do not have the car in gear.
  • The car may be just idling too low which can be adjusted very easily with a screwdriver if you drive an older car. There is a small screw on the throttle body where the throttle cable connects to it you can adjust the screw to make the car idle smoother.

Warnings

  • Often, you will have to reach into cramped, hot spaces to check your fluid. Check your manual for the proper location. Take care not to be burned by engine parts. Wear long sleeve shirts or gloves as appropriate. Also, when adding fluid, it is a good idea to use a funnel with an appropriate length of neck.
  • Use the proper type for your vehicle. Do not overfill.
  • Inspect the EGR valve while outdoors, or in a well-ventilated area, to reduce exposure to fumes from the carburetor cleaner or exhaust.

Related Articles

Retrieved from "https://kipkis.com/index.php?title=Determine_Why_a_Car_Stalls_at_Intersections&oldid=330793"