What is the 2005-2010 Chevrolet Cobalt 4T45-E Automatic Shift Solenoid Failure — Harsh Shifts and Limp Mode?

The 4T45-E four-speed automatic used behind the 2.2L and 2.4L Ecotec relies on 1-2 and 2-3 shift solenoids mounted on the valve body under the transmission side cover. The solenoid windings and valve pintles wear and stick, so the TCM cannot command the shift on time: owners repo… Repairs typically run $350-$900. Severity: high.

What is the 2005-2010 Chevrolet Cobalt Ecotec Engine Timing Chain Stretch and Guide Wear?

The 2.2L and 2.0L Ecotec engines in the Cobalt develop timing chain stretch and timing chain guide deterioration. The plastic timing chain guides wear over time, causing the chain to become slack and noisy. If left unaddressed, the timing chain can skip teeth, causing valve timin… Repairs typically run $400-$1,500. Severity: medium.

What is the 2005-2010 Chevrolet Cobalt Premature Front Wheel Hub Bearing Failure?

Front wheel hub bearings commonly fail prematurely, sometimes as early as 50,000 miles. The sealed bearing units develop excessive play and noise due to poor sealing that allows water intrusion. Road salt environments accelerate failure dramatically. Repairs typically run $200-$400. Severity: medium.

What is the 2005-2010 Chevrolet Cobalt Fuel Pump Module Failure Causing Stalling and No-Start?

The in-tank fuel pump assembly is prone to failure, often due to deteriorating fuel pump wiring harness connections or internal pump motor wear. Symptoms appear gradually with intermittent stalling before complete failure. Hot weather exacerbates the problem as heat-soaked pumps… Repairs typically run $400-$700. Severity: medium.

What is the 2005-2010 Chevrolet Cobalt Ecotec Thermostat Housing and Water Pump Coolant Leak — Slow Loss with No Visible Puddle?

On the 2.2L/2.4L Ecotec the thermostat is integrated into a plastic housing on the back side of the engine facing the firewall, and the water pump sits behind the timing cover on the passenger side. Both are recurring leak points. The rear thermostat housing seal hardens and the… Repairs typically run $150-$600. Severity: medium.

What is the 2005-2010 Chevrolet Cobalt Intermediate Steering Shaft Loses Lubrication — Clunk/Knock Felt Through Steering Wheel?

The Delta-platform intermediate steering shaft (the splined slip-joint between the column and the rack pinion) was under-lubricated from the factory. The splines fret and dry out, so every reversal of steering load produces a metallic clunk or knock felt in the steering wheel and… Repairs typically run $180-$450. Severity: medium.

What is the 2005-2007 Chevrolet Cobalt LSJ Supercharger Nylon Coupler Wear — Idle Rattle and Eventual Snout Failure (Cobalt SS Supercharged)?

On the 2005-2007 supercharged Cobalt SS with the 2.0L LSJ, the Eaton M62 blower is driven through a nylon isolator coupler inside the snout that cushions torsional pulses from the crank. Belt-driven torsional oscillation at idle repeatedly loads and unloads the metal drive pins a… Repairs typically run $150-$900. Severity: medium.

What is the 2005-2010 Chevrolet Cobalt Sunroof Drain Tubes Clog or Pop Off the Barb — Water in the Footwells and A-Pillar Wiring?

Sunroof-equipped Cobalts route water from the sunroof tray through four drain tubes, one at each corner, with the front pair running down inside the A-pillars. The front tubes commonly either clog with debris or slip completely off the barb at the sunroof tray — a repeatedly docu… Repairs typically run $0-$300. Severity: medium.

What is the 2005-2010 Chevrolet Cobalt Catalytic Converter Efficiency Loss (P0420) Following Long-Term Misfire or Oil Consumption?

The Cobalt is a repeat offender for P0420 (Catalyst System Efficiency Below Threshold, Bank 1). The Ecotec's two chronic upstream problems — random misfire from failing ignition coils/coil-pack modules, and oil consumption past worn rings and valve seals — poison and overheat the… Repairs typically run $400-$1,600. Severity: medium.

What is the 2005-2010 Chevrolet Cobalt Front Sway Bar End Links and Stabilizer Bushings Wear Out — Rattle Over Bumps?

The Cobalt's front stabilizer bar end links (the common Delta-platform link, aftermarket P/N K80252, shared with HHR, Malibu, Aura and ION) wear out early — often by 60-80k miles. The ball sockets develop play and the rubber stabilizer bar bushings harden and split, so the bar kn… Repairs typically run $90-$320. Severity: low.

What is the 2005-2010 Chevrolet Cobalt Interior Door Handle and Trim Coating Delamination — Sharp Peeling Metallic Finish?

The Cobalt's interior door handles and several trim inserts use a metallic-look coating sprayed over plastic rather than plated metal. The coating loses adhesion and flakes off in sheets, starting on the driver's inner door handle where hands contact it, and spreading to the surr… Repairs typically run $30-$200. Severity: low.

Chevrolet · Known Issues

2005 Chevrolet Cobalt Problems: 14 Known Issues

2005 model year · 5,323+ owner reports · Updated August 2026

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According to Au7o's analysis of 5,323+ owner reports, the 2005 Chevrolet Cobalt has 14 documented known issues, with 4 rated critical. The most serious are Defective Ignition Switch Causing Engine Shutoff and Airbag Failure ($0-$0 repair), Electric Power Steering Motor Sudden Failure ($0-$800 repair), 4T45-E Automatic Shift Solenoid Failure — Harsh Shifts and Limp Mode ($350-$900 repair) and Accelerator Pedal Position Sensor / Electronic Throttle Fault — "Engine Power Reduced" Limp Mode ($150-$500 repair). The most commonly reported issue is Defective Ignition Switch Causing Engine Shutoff and Airbag Failure with 4,503 owner reports. Across all issues with published estimates, repair costs range from $30 to $1,600. DIY maintenance guides at au7o.io.

Frequently Asked Questions

What are the most common Chevrolet Cobalt problems?

According to Au7o's analysis of 5,323+ owner reports, the 2005 Chevrolet Cobalt has 14 documented issues. The most frequently reported are: Defective Ignition Switch Causing Engine Shutoff and Airbag Failure, Electric Power Steering Motor Sudden Failure, 4T45-E Automatic Shift Solenoid Failure — Harsh Shifts and Limp Mode. Of these, 4 are rated critical and should be addressed promptly.

Is the Chevrolet Cobalt reliable?

The 2005 Chevrolet Cobalt has 14 known issues documented across 5,323+ owner reports. 4 issues are rated critical: Defective Ignition Switch Causing Engine Shutoff and Airbag Failure and Electric Power Steering Motor Sudden Failure and 4T45-E Automatic Shift Solenoid Failure — Harsh Shifts and Limp Mode and Accelerator Pedal Position Sensor / Electronic Throttle Fault — "Engine Power Reduced" Limp Mode. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.

How much does it cost to fix common Chevrolet Cobalt problems?

Repair costs for known Chevrolet Cobalt issues range from $0 to $1,600, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, Defective Ignition Switch Causing Engine Shutoff and Airbag Failure, typically costs $0-$0 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 2005-2010 Chevrolet Cobalt Defective Ignition Switch Causing Engine Shutoff and Airbag Failure?

The Chevrolet Cobalt was at the center of the largest safety scandal in GM history. Defective ignition switches could turn from "Run" to "Accessory" or "Off" position while driving, triggered by heavy keychains, road vibrations, or knee contact. When the ignition turns off, the e… Repairs typically run $0-$0. Severity: high.

What is the 2005-2010 Chevrolet Cobalt Electric Power Steering Motor Sudden Failure?

The Cobalt equipped with electric power steering (EPS) is subject to a recall for sudden loss of power steering assist while driving. The EPS motor can fail without warning at any speed, requiring significantly more effort to steer the vehicle. The 2005 model year alone has 128 c… Repairs typically run $0-$800. Severity: high.

All 14 Known Issues

Other Chevrolet Models

Frequently Asked Questions

What are the most common Chevrolet Cobalt problems?

Is the Chevrolet Cobalt reliable?

How much does it cost to fix common Chevrolet Cobalt problems?

What is the 2005-2010 Chevrolet Cobalt Defective Ignition Switch Causing Engine Shutoff and Airbag Failure?

What is the 2005-2010 Chevrolet Cobalt Electric Power Steering Motor Sudden Failure?

2005-2010 Chevrolet Cobalt: Electric Power Steering Motor Sudden Failure#

2005-2010 Chevrolet Cobalt: Premature Front Wheel Hub Bearing Failure#

2005-2010 Chevrolet Cobalt: Front Sway Bar End Links and Stabilizer Bushings Wear Out — Rattle Over Bumps#

2005-2010 Chevrolet Cobalt: Defective Ignition Switch Causing Engine Shutoff and Airbag Failure#

2005-2010 Chevrolet Cobalt: 4T45-E Automatic Shift Solenoid Failure — Harsh Shifts and Limp Mode#

2005-2010 Chevrolet Cobalt: Accelerator Pedal Position Sensor / Electronic Throttle Fault — "Engine Power Reduced" Limp Mode#

2005-2010 Chevrolet Cobalt: Ecotec Engine Timing Chain Stretch and Guide Wear#

2005-2007 Chevrolet Cobalt: LSJ Supercharger Nylon Coupler Wear — Idle Rattle and Eventual Snout Failure (Cobalt SS Supercharged)#

2005-2010 Chevrolet Cobalt: Fuel Pump Module Failure Causing Stalling and No-Start#

2005-2010 Chevrolet Cobalt: Ecotec Thermostat Housing and Water Pump Coolant Leak — Slow Loss with No Visible Puddle#

2005-2010 Chevrolet Cobalt: Intermediate Steering Shaft Loses Lubrication — Clunk/Knock Felt Through Steering Wheel#

2005-2010 Chevrolet Cobalt: Sunroof Drain Tubes Clog or Pop Off the Barb — Water in the Footwells and A-Pillar Wiring#

2005-2010 Chevrolet Cobalt: Catalytic Converter Efficiency Loss (P0420) Following Long-Term Misfire or Oil Consumption#

2005-2010 Chevrolet Cobalt: Interior Door Handle and Trim Coating Delamination — Sharp Peeling Metallic Finish#