Skip the auto shop - Our mechanics make house calls

Q: Transmission is not shifting

asked by on

Car will not shift it gets to about 25 mph and won't shift I floor it and get it up to 4000 rpm and it makes a backfire noise after I do this a few times it start to run better I checked the fluid and it's ok

My car has 98000 miles.
My car has an automatic transmission.

This may be a sign of low transmission fluid or a faulty transmission control solenoid. As you know, automatic transmissions use pressurized hydraulic fluid to change gears. Every time a gear change is required, the car’s computer activates a transmission solenoid, which directs transmission fluid into the valve body to engage the correct gear. When this is faulty or not working properly, this can cause a delay in gear shifting or in some cases cause the car to not shift at all. This type of problem is amplified any time the transmission is low on fluid creating a drop in hydraulic pressure.

This may also suggest a failing speed sensor. The transmission speed sensor is a magnetic sensor that provides this information, allowing the transmission to shift smoothly. The sensor counts the internal number of revolutions of the transmission and transmits that information to the transmission control unit, where the data is used to determine the rotational speed. As the rotation increases, the control unit directs the changing of gears. When this is not working properly, this may cause the transmission to shift erratically or in some cases not at all. I would recommend having an expert from YourMechanic come to your location to take the car for a test drive to more specifically determine the cause for this.

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!

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: My car will turn on and idle for maybe 2 minutes if I'm lucky and then shut back off

Hello. There are a lot of things that can cause this on your vehicle. If it will run for a few minutes or so, then that usually means that something is shutting down such as the ignition module or the...

Q: Service AWD System light is coming on

Hello. The "Service AWD System" light comes on when the computer detects that there is an issue with the AWD system. In most cases an issue with the AWD system will disable the system completely in order to protect the...

Q: Need to replace the leak detection pump on my jeep.

Billing question sent to CS for the cost of replacing the leak detection pump on a 2005 jeep liberty.

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...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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...