Q: Sometimes my car will not shift into overdrive and then sometimes it does, any idea what could be causing this?

asked by on March 04, 2017

I have noticed while driving my tercel that sometimes it will shift into overdrive and othertimes it will not. There is no check engine light on in the car and the transmission shifts great in 1, 2, 3. I have no idea what could be causing this problem or where to start.

My car has 238000 miles.
My car has an automatic transmission.

This symptom is the TCC (Torque Converter Clutch) is slipping in and out while driving. To check this condition, scan the computer to see whether the TCC action is being commanded by the computer. There could be a problem with the throttle position sensor (TPS) on the throttle body causing the engine to rev up and down to make the TCC disengage and engage. If there is no issue with the TPS, then the TCC valve in the valve body (brain of the transmission) inside the transmission has made its bore larger than the valve and causing an internal leak making the valve buzz back and forth. This action will cause the TCC to engage and disengage multiple times as long as the TCC is to be engaged. I recommend seeking out a professional, such as one from Your Mechanic, to help you diagnose your transmission.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Car stuck in third gear
It does sound like a transmission problem. I would have to recommend taking your car to a European transmission specialist, such as one from YourMechanic. They may be able to clean out the valve body, replace the filter and fluid,...
when I turn the ignition switch to on, the ac compressor clutch will engaged. Disconnected the ac control switch and still
On some earlier years of Chevy they used to have the A/C compressor to come on when you are turning off the engine to help the prevent the engine from suffering from excessive after-run conditions that the engine will continue...
I have a crunching/grinding like sound coming from my front left wheel when i only do tight turns,,just of recent i had a new tyr
I assume you have a vehicle that is front wheel drive and the noise is from the axle constant velocity joint binding. The outer boot gets torn from normal use and will get dirt into the joint and lube gets...
Vapor canister purge valve has a loud tick? Very rough idle upon starting after a refueling.
Hey there. The purge valve ticking noise is most likely normal and should not be noticed inside the cab when the windows are up. If it is too loud inside the cab, then have the valve replaced. The purge valve...
Car jumps in 5th when pushing gas pedal
This suggests you may have a worn or failing 5th gear synchronizer in your transmission. As you may know, when a clutch drags, it is not letting go of the disk fully which overloads the synchros and burns up the...
Possible problem with alternator
Hello. You are correct, the next step is to remove and test, or just go ahead and replace the alternator. Replacement aftermarket alternators for the 2001 Pontiac Grand Am cover years 2000-2003. So reasonably you can conclude that the alternator...
Power steering upon start up shows gurgling in reservoir after hot starts foaming and making noise 2007 Mercedes S600
Hi - your symptoms suggest the power steering system (https://www.yourmechanic.com/question/power-steering-leak_2) has either run low on fluid, sucking air into the system, or the system filter is clogged, creating air in the system through cavitation of the pump (vacuum bubbles). I...
My Ford Ranger 1998 got too hot and I heard a pop.
Hi there. The noise you heard could have been fuel left in the cylinder when the engine was hot and igniting the fuel as an explosion. That is why you saw smoke coming out of the pipe on the engine....
overfilled transmission fluid
You will need to have the excess fluid sucked out of the transmission so it is not overfull through the fill tube. Most mechanics have a suction tool that can pull out the excess fluid for you. The transmission may...

Related articles

The Best Used Cars to Buy for Long Commutes
Most Most of us are faced with the prospect of commuting back and forth to work on a daily basis, but some have a much longer drive than others. When it comes time to buy a car, you need to...
How to Buy a Toyota Prius
The Toyota Prius (https://www.yourmechanic.com/article/how-to-drive-a-toyota-prius) is one of the most popular hybrid models on the automotive market, and it comes with an array of perks. A Prius is more environmentally friendly than your average fuel-guzzling car, leaving less of an ecological...
What Does the Automatic Transmission/Automatic Gearbox Warning Light Mean?
The automatic transmission warning light means there's an issue with the transmission, possibly the fluid temperature, fluid level, or pressure.