Skip the auto shop - Our mechanics make house calls

Q: Diagnose torque converter selenoid or transmission

asked by on

have an 06 avalanche 1500 ls 2wd 5.3 automatic that will drive fine for 30 mins then suddenly lose acceleration rpms still move but wont increase speed on road but once it cools down half n hr or so it will drive fine again no clicks or noise no shifting problems and it is not producing any codes at autozone the transmission is only 3yrs old fluid is full but has a hint of dirt to it but not burnt black or metal still red and full no leaks im not sure where to start diy cant afford to have shop repair can u give me ways to test if its the tranny torque converter or selenoid or any other ideas on diagnosis would be helpful please

My car has 200000 miles.
My car has an automatic transmission.

Hi there. The computer could be putting the vehicle into limp mode due to an issue that may be happening and reduces the engine performance. Check the battery, alternator, and all of the sensors on the engine and make sure that they are all working properly. If the engine is running normally, then there could be an issue with the transmission.

To check the transmission torque converter complete the following steps:

(1): Set the parking brake and start the engine. (2): Press down on the service brake and hold it on the floor (3): Put the transmission selector in the ’D’ (drive) position (4): Press down on the accelerator pedal to the floor for 3 to 5 seconds (5): While the engine rpm is high, monitor how high the rpm goes with the accelerator pedal on the floor (6): Let off the accelerator pedal and put the transmission in park (7): Shut off the engine and then release the service brake and parking brake

Make sure that when you perform this test, have your vehicle in a location where there is nothing in front of the vehicle to prevent any damage to your vehicle if for some reason the brakes fail during the test. It is best to add a pair of chocks to the wheels for added safety. If you need further assistance with your vehicle stalling for no reason after 30 minutes of driving, then seek out a professional, such as one from Your Mechanic, to help you.

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: Is the solenoid and starter one unit or separate.

Most if not all starters on the market will include the starter solenoid with the replacement starter for this car. You may be able to purchase the parts separate but it is not common practice since it adds labor to...

Q: When I drive it shakes ween I get on the gas it drive good

Shaking or vibration may be caused by many different things such as faulty spark plugs, poor fuel pressure or misfires. Other things such as a faulty idle air control valve may cause the engine idle to drop below the normal...

Q: Tcc solenoid broke .

Your best option is to buy a service manual; it will detail the steps required to replace the TCC solenoids. Unfortunately, YourMechanic does not work on transmissions so it may be necessary to take the car to a transmission shop,...

Related articles

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...
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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...