2001 jerks between 45 and 55mphs

[DAVE7695]

I have a 2001 Impala with a 3.8L. I was wondering why between 45 and 55mph. Lets say going uphill or by giving it gas right when the speedometer hits the above mphs my car jerks. I just came from a 800 mile trip and besides the above symptoms the car ran great even got 32 miles per gallon. It has been doing this for about 4 months. Before my trip i had the trans fluid changed and also the fuel pump. any ideas what it could be?

[BNaylor]

Sounds like have the old "chuggle" or fishbite" which is the torque convertor locking/unlocking. Best place to start are the spark plugs and ignition wires.

GM has a TSB out on the problem which calls for checking out and/or replacing the throttle position sensor (TPS) but that very seldom if ever resolves the issue. Any engine conditon will affect the tranny so that has to be looked at first.

[billyo69]

I would be willing to bet it is either your fuel filter or cat converter

[DAVE7695]

Have replaced plugs, wires and fuel pump with gm parts.

[billyo69]

I assume you canged your fuel filter. If so check your cat converter. My 01 ls had a bad cat and i was sure my tranny was gone.

[BNaylor]

No guarantee this will work but disconnect the battery negative cable overnight, reconnect and then see what it does. If radio Theftlock is active be sure to have your codes before disconnecting the battery.

[richtazz]

Like Bob said, no guarantee, but reliable sources have stated that disconnecting the battery overnight works, strange as it sounds. A $0 proceedure is way better than spending money if it works.

[troy1]

check the VSS sensor connector to see if its rubbing on the power steering line if so adjust the power steering line accordingly. One other thing it could be a bad TCC or PWM TCC solenoid a good tranny shop will be able to tell you by watching the duty cycle of the TCC PWM solenoid on a scanner. And the last thing to check is the PCS a worn out PCS can cause the TCC to act funny do to low pressures. This also can be checked at a good tranny shop.

[tractorboy]

I have even heard of the MAF sensor being dirty ( ford) so the it registered lower air flow and tried to downshift or upshift the tranny at the wrong time. The story I heard the mechanic even rebuilt the transmission only to find that it still did the same. Turned out some Throttle bodk cleaner cured what was wrong. CAUTION : NEVER USE CARB CLEANER ON A THROTTLE BODY OR NEAR THE THROTTLE BODY.

[ysteve]

If you not gonna be able to find a problem, last thing i would check Tranny cooler FLOW. I think this can do only GM or if you have special tool. Good luck.

[tractorboy]

Probabaly a scan tool might not be a bad idea. I do not know if they can show flow of the t fluid, i know they can show the temp.

[ysteve]

A/T - Fluid Cooler Flushing
Bulletin No.: 02-07-30-052D
Date: February 06, 2006
INFORMATION
Subject:
Automatic Transmission Oil Cooler Flush and Flow Test Essential Tool J 45096 TransFlow(R)
Models:
2007 and Prior Passenger Cars and Light Duty Trucks
2003-2007 HUMMER H2
2006-2007 HUMMER H3
with Automatic Transmission/Transaxle including Allison(R) Transmissions
Supercede:
This bulletin is being revised to add models, model years and additional warranty information. This bulletin also cancels and replaces Corporate Bulletin Number 03-07-30-002B. Please discard Corporate Bulletin Numbers 03-07-30-002B and 02-07-30-052C (Section 07 - Transmission/Transaxle).
The J 45096 transmission oil cooling system flush and flow test tool replaces current tool J 35944-A. J 45096 is a self-contained unit utilizing a 12-volt flow meter, shop air supply and DEXRON(R) VI automatic transmission fluid (ATF). In the flush mode, transmission fluid is cycled through the transmission oil cooling system. High-pressure air is automatically injected into the fluid stream adding agitation to the ATF oil to enhance the removal of contaminated ATF oil and debris. In the flow mode, an electronic flow meter is used to measure the flow capability of the ATF oil cooling system. A digital display indicates the ATF oil flow rate in gallons per minute (GPM) along with the amount of ATF oil in the supply vessel, supply vessel ATF oil temperature, machine cycles and the operating mode. The supply oil vessel has 30 L (32 qt) capacity and the waste oil vessel has 32 L (34 qt) capacity. The waste oil vessel is constructed of a translucent composite material that allows the user to easily identify the oil level. The waste oil vessel can accommodate vacuum evacuation and gravity draining. In the code mode, a random, encrypted code is generated that can be used for verification of flow test results.
Current essential cooler line adapters are used to connect the J 45096 to the automatic transmission oil cooler lines that allows J 45096 to adapt to General Motors passenger cars and light duty trucks, current and past models (except the Pontiac Vibe, Wave and Chevrolet Aveo).
The tool may be adapted for use on the Pontiac Vibe, Wave and Chevrolet Aveo by dealership personnel with a barbed hose connector and rubber hose obtained locally. The Vibe's/Wave's/Aveo's transmission has a transmission oil requirement which is slightly different than DEXRON(R) VI ATF. However, flushing the cooler with DEXRON(R) VI automatic transmission fluid is an acceptable service procedure. Very little fluid remains in the cooler after the flush procedure and the residual DEXRON(R) VI ATF in the cooler is compatible with the Vibe's/Wave's/Aveo's transmission fluid.


Note: Insufficient oil flow through the ATF oil cooling system will cause premature transmission failure. The required minimum ATF oil flow rate reading is directly related to the supply oil temperature. Refer to the flow rate reference chart for the oil flow rate specification based on the temperature of the ATF in the supply vessel.
Helpful Hints for Maintaining the Temperature at or above 18°C (65°F)
Important: ^The temperature of the supply vessel oil must be 18°C (65°F) or greater for J 45096 to operate. It is recommended to store the J 45096 in an area of the dealership where the room temperature remains at or above 18°C (65°F) when not in use.
^Do not attempt to increase the fluid temperature in the Transflow(R) machine with an engine oil dipstick, or any other immersion type heater. The Transflow(R) machine has a check valve in the supply reservoir. Inserting a heater will damage the check valve and the subsequent repair expense would be the dealer's responsibility.
Store the Transmission Cooling System Service Tool, J 45096, Transflow(R) machine in a room where the temperature is maintained at or above 18°C (65°F). Keep the ATF level in the reservoir low when the Transmission Cooling System Service Tool, J 45096, Transflow(R), is not in use. Store several gallons of oil in an area where the temperature is maintained at or above 18°C (65°F). Fill the reservoir of the J 45096 as needed before using the machine on each repair. With the ATF in a tightly sealed container, place the container in a tub of hot water for a period of time. Then pour the ATF into the reservoir. This method works best with a low fluid level in the reservoir.
Place the Transflow(R) machine in the direct sunlight with the cabinet door open to expose the reservoir to the rays of the warm sun.
Flush / Flow Test Procedure
Refer to SI for Automatic Transmission Oil Cooler Flushing and Flow Test J 45096 for the appropriate procedure.
Important: The J 45096 can be used to flush the transmission oil cooler system on an Allison equipped vehicle, but the flow meter should not be utilized. Refer to SI for Automatic Transmission Oil Cooler Flushing and Flow Test J 45096 for the appropriate flow check procedure.
Machine Displays
After completion of the flush and flow test, the following information is to be recorded on the repair order. This information is displayed on the Transmission Cooling System Service Tool, J 45096, Transflow(R) machine when the dial is in the code position.
^Tested flow rate (displayed in Gallons Per Minute (GPM)
^Temperature (displayed is degrees Fahrenheit)
^Cycle number (a number)
^Seven digit Alpha/Numeric flow code (i.e. A10DFB2)
Warranty Information
Performing a transmission oil cooling system flush and flow test will use between 4.7-7.5 L (5-8 qts) of DEXRON(R)VI transmission fluid. The amount of transmission fluid (ATF), (DEXRON(R)VI) (fluid) that is to be charged for the flush portion of the repair should not exceed the allowable charge for 7.5 L (2 gal) of fluid. This expense should be shown in the net item column of the warranty claim document.
The Seven digit Alpha/Numeric flow code, i.e. A10DFB2, MUST be written on the repair order and placed in the comments section of the warranty claim. Any repair that requires the technician to contact the Product Quality Center (PQC) must also include the seven digit flow code. The agent will request the seven digit flow code and add the information to the PQC case prior to providing authorization for the warranty claim.
In Canada, the Seven digit Alpha/Numeric flow code, i.e. A10DFB2, MUST be written on the repair order. Any repair that requires the technician to contact the Product Quality Center (PQC) must also include the seven digit flow code. The agent will request the seven digit flow code and add the information to the PQC case prior to providing authorization for the warranty claim.
All labor operations that include removal of the torque converter include labor time to flush the transmission oil cooler system.

[tractorboy]

how much does the tool cost,

[ysteve]

I have no clue about price, but i think best way to do is go to dealer.

[micali]

what did you find out?