GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Optra 🢒 Engine 🢒 Engine Controls - 1.6L (L91) 🢒 Symptoms - Automatic Transmission
Table 1: Transaxle Oil Leakage
Table 2: Noise

Oil Leakage

Important: Carefully localization of leakage points may make it possible to prevent incorrect or cost-intensive repairs.

Test Steps

    • Thoroughly clean the transaxle, the engine, and surrounding area. You may use a steam jet for this purpose.
    • To locate leakage, use a suitable identifying spray or similar product.
    • Depending on the amount of leakage, take the vehicle for a short or a longer test drive. It may prove sufficient to place the car on a hoist and run the engine at idle speed to trance the leak.
    • If possible, determine exactly which type of oil is escaping.

Transaxle Oil Leakage

Condition

Action

Oil pump - Torque converter sealing
    • Visually inspect the torque converter sealing.
    • Replace the converter sealing.

Crankshaft sealing ring
    • Determine whether engine oil or transmission fluid is leaking.
    • If the leak is engine oil, replace the sealing ring.

Torque converter
    • Visually inspect the torque converter.
    • Fit an exchange converter.

Oil content too high
    • Inspect the oil level, both TFT and axle oil.

       Important: Comply with the measuring procedure. Refer to Transmission Fluid Level Inspection .

    • Inspect the oil level a the overflow plug and adjust to the proper level if necessary.
    • Correct the oil level and check after a test drive.

O-ring at Bolt Head Damaged or Missing
    • Inspect the O-ring.
    • Replace the O-ring if necessary.

Shaft seal
    • Visually inspect the shaft seal.
    • Replace the sealing ring.

Loose hose clamp
    • Verify that the hose clamp fits tightly.
    • If necessary, tighten the clamp

Improperly installed oil pan gasket
    • Verify that the gasket is positioned properly.
    • Install the gasket properly.

Damaged oil pan gasket
    • Visually inspect the gasket for damage.
    • Replace the gasket.

Loose bolt at bracket

Verify the torque of the bracket bolt. Tighten the bolt, if necessary.

Sealing ring at oil dipstick
    • Inspect the O-ring.
    • If necessary, replace the O-ring.

Defective sealing ring near end-cover connection
    • Inspect the sealing rings.
    • Replace the sealing ring with new sealing ring.
    • Inspect the O-ring

Sealing ring selector shaft
  1. Inspect the sealing ring.
  2. Replace the sealing ring.

O-ring at socket outlet
    • Inspect the O-ring.
    • Replace the O-ring.

O-ring and speed sensor connection
    • Inspect the O-ring.
    • Replace the O-ring.

Oil leak incorrectly identified

No oil leak is possible at this point.

Leaking speed sensor
    • Inspect the speed sensor.
    • Replace the speed sensor.

Hair line crack at the piping in the connection area, sealing ring fit in transaxle housing
    • Pressurize the line with compressed air.
    • Replace the lines.

Defective or incorrect O-ring
    • Inspect the O-ring.
    • If necessary, replace the O-ring.

Loose plug

Verify the torque fo the screw plug.

Noise

Condition

Action

TFT level is too low.

Important: When the TFT level is too low, the gear wheels from the transaxle oil pump might generate noise.

Inspect the TFT level and fill to the proper level.

Broken monolith in the catalytic converter
    • Inspect the exhaust by shaking the catalytic converter casing.
    • If necessary, replace the catalytic converter.

Noise from auxiliaries, such as exhaust system, alternator, drive shafts.

Inspect the following components to eliminate the faults:

    • The exhaust system
    • The alternator
    • The drive shafts

Noise from tires or wheel bearings

If necessary, eliminate the faults from the components.

Noise from planetary gears

A whistling noise on traction and overrun, in first gear only, is caused by high rotating speeds. This noise is functionally unavoidable.

Cumulative tooth backlash in the complete drive line

Production status. The customer must be convinced.

Jerky noise of the parking lock, when the vehicle is standing on a slope
    • Load reversal reaction.
    • Apply the hand brake before selecting the parking lock (position P).

The engine's torsional vibrations are being transmitted to the drive shafts.
    • At low speeds in fourth gear, a vibration can arise from driving at too low an engine speed.
    • Noise is functionally unavoidable due to tolerances. Convince the customer.

A loose torque reaction strut

Inspect the mounting and repair as necessary.

 

Shift Quality

Important: The assessment of shift quality is an individual, subjective matter. Take note of how the customer describes the complaint and how the customer handles the vehicle and the controls.

A sudden deterioration of shif t quality may also be caused by the transaxle selection an emergency or sustiture program.

Test Steps

    • Perform the general procedures described in the diagnostic section of this book.
    • Perform a test drive to answer the following questions:
       - Under which driving situations does the shift quality condition arise?
       - To which shifts does the condition apply?
       - Is the condition reproducible within a short period, or has the condition only occurred sporadically or on a single occasion?
    • Inspect the oil level and the oil quality.
    • Interrogate the fault memory and read out the measurement block data.

Condition

Action

Rapid pressure build-up in the clutch

This is an operating error caused by selecting a position several times in quick succession.

Jerk when the parking lock is released

Refer to the Noise table in this procedure.

Incorrect electronic transaxle control module

Refer to the data status for the transaxle control module.

The accelerator pedal is in an indefinite position between full throttle and kick down.
    • Persuade the customer to choose clearly between kick down and full throttle.
    • Inspect the setting according to the engine repair instruction. Adjust, if necessary.

Control overlap between two clutches during a shift

This is a production status. Convince the customer.

Temperature sensor - not fault memory

Refer to Drive Range - Fourth Gear, Emergency/Substitute Mode or Drive Range - Third Gear, Emergency/Substitute Mode .

Incorrect kick down setting

Inspect the following conditions:

    • Verify that the floor mat is not obstructing the accelerator pedal.
    • Inspect the kick down for proper operation.
 
 

Malfunction

Important: These malfunctions concern transaxle function such as forward and reverse traction, and all types of shifts. Entries will not always be made in the fault memory.

Test Steps

Perform the general procedures according to the automatic transaxle diagnostic procedure:

    • Test drive
    • Inspect the oil level and quality
    • Interrogate fault memory

Condition

Action

Defective clutch in the transaxle if no Drive gear is available with the TCM disconnected

This condition is usually due to too little oil being added, or to internal damage. Repair is not possible. If necessary, exchange the transaxle.

The kick down switch is not functioning properly

For checking and remedial action. Refer to Drive Range - Fourth Gear, Emergency/Substitute Mode or Drive Range - Third Gear, Emergency/Substitute Mode .

The vehicle is in Emergency mode.

For checking and remedial action. Refer to Drive Range - Fourth Gear, Emergency/Substitute Mode or Drive Range - Third Gear, Emergency/Substitute Mode .