2007 GMC T7500

The 2007 GMC T7500 is a medium-duty truck often used for commercial purposes. It offered a range of engine and transmission options to suit various needs. While generally considered a reliable workhorse, some common issues have been reported by owners. The T7500 provides a good balance of capability and affordability, but some owners have reported the ride to be fairly stiff and handling less responsive than lighter-duty trucks. Engine options include the Duramax 6.6L diesel V8 and the Vortec 8.1L gas V8. The Duramax is favored for its power (rated around 330 HP and 620 lb-ft of torque) and fuel efficiency in demanding applications, while the Vortec offers a lower initial cost but sacrifices fuel economy. Transmission options included Allison automatic transmissions, with the specific model varying depending on the engine and application.

Engine

Duramax 6.6L Diesel V8

• Fuel Injector Failure
  • Description/Symptoms: Rough running engine, misfires, black smoke from the exhaust, decreased fuel economy. Often caused by contaminated fuel or normal wear and tear.
  • Solution: Replace the faulty fuel injector(s). Ensure the fuel system is properly flushed and use a high-quality fuel filter.
  • Estimated Cost to Fix: $400 - $800+ per injector (parts and labor).
  • Recalls: None Found
• Glow Plug Issues
  • Description/Symptoms: Hard starting, excessive white smoke upon startup, especially in cold weather.
  • Solution: Replace the faulty glow plug(s) and inspect the glow plug control module.
  • Estimated Cost to Fix: $150 - $400+ (parts and labor, depending on how many plugs need replacement).
  • Recalls: None Found

Vortec 8.1L Gas V8

• Intake Manifold Gasket Leak
  • Description/Symptoms: Coolant leak, overheating, rough running engine, loss of coolant, possible “sweet” smell from the engine bay.
  • Solution: Replace the intake manifold gasket.
  • Estimated Cost to Fix: $400 - $800+ (parts and labor).
  • Recalls: None Found
• Oil Consumption
  • Description/Symptoms: Excessive oil consumption, blue smoke from the exhaust. Can be caused by worn valve stem seals or piston rings.
  • Solution: Replace valve stem seals, or in more severe cases, overhaul the engine including replacing the piston rings.
  • Estimated Cost to Fix: $800+ for valve stem seals, $3000+ for a full engine overhaul.
  • Recalls: None Found

Transmission

Allison Automatic Transmissions (Specific Model Varies)

• Torque Converter Clutch (TCC) Failure
  • Description/Symptoms: Shuddering during lockup, poor fuel economy, transmission overheating.
  • Solution: Replace the torque converter.
  • Estimated Cost to Fix: $1500 - $3000+ (parts and labor).
  • Recalls: None Found
• Shift Solenoid Issues
  • Description/Symptoms: Erratic shifting, failure to shift, transmission slipping.
  • Solution: Replace the faulty shift solenoid(s).
  • Estimated Cost to Fix: $300 - $800+ (parts and labor).
  • Recalls: None Found

Suspension

• Leaf Spring Sagging/Cracking
  • Description/Symptoms: Sagging rear end, poor ride quality, reduced load capacity, visible cracks in the leaf springs.
  • Solution: Replace the leaf springs.
  • Estimated Cost to Fix: $500 - $1500+ per spring (parts and labor).
  • Recalls: None Found
• Worn Ball Joints/Tie Rod Ends
  • Description/Symptoms: Loose steering, clunking noises from the front end, uneven tire wear.
  • Solution: Replace the worn ball joints and tie rod ends.
  • Estimated Cost to Fix: $300 - $800+ per side (parts and labor).
  • Recalls: None Found

Electrical

• Wiring Harness Corrosion
  • Description/Symptoms: Intermittent electrical issues, check engine lights, malfunctioning sensors, starting problems. Common in areas that use road salt.
  • Solution: Repair or replace the corroded wiring harness sections. Use dielectric grease on electrical connections.
  • Estimated Cost to Fix: $200 - $1000+ depending on the extent of the damage and the complexity of the repair.
  • Recalls: None Found
• Alternator Failure
  • Description/Symptoms: Dimming lights, weak battery, difficulty starting, battery light on the dashboard.
  • Solution: Replace the alternator.
  • Estimated Cost to Fix: $300 - $700+ (parts and labor).
  • Recalls: None Found

Exterior

• Rust on Cab Corners/Rocker Panels
  • Description/Symptoms: Rust forming on the lower portions of the cab and rocker panels, especially in areas with road salt use.
  • Solution: Cut out the rusted sections and weld in new metal, followed by body filler, primer, and paint.
  • Estimated Cost to Fix: $500 - $2000+ per section, depending on the extent of the rust and the quality of the repair.
  • Recalls: None Found
• Headlight Lens Clouding/Yellowing
  • Description/Symptoms: Headlight lenses become cloudy or yellowed, reducing visibility at night.
  • Solution: Polish the headlight lenses or replace the headlight assemblies.
  • Estimated Cost to Fix: $50 - $150 for polishing, $200 - $500+ for replacement (parts and labor).
  • Recalls: None Found

Interior

• HVAC Blower Motor Failure
  • Description/Symptoms: Blower motor not working, only working on certain speeds, or making excessive noise.
  • Solution: Replace the blower motor or blower motor resistor.
  • Estimated Cost to Fix: $150 - $400+ (parts and labor).
  • Recalls: None Found

Summary

The 2007 GMC T7500, like many medium-duty trucks, can experience a range of issues related to engine, transmission, suspension, electrical systems, and body corrosion, especially as they age. Engine problems like fuel injector or intake manifold gasket failures can be costly. Transmission problems can range from moderate to costly as well. Suspension and electrical problems can cause safety concerns. Rust is a common enemy, particularly in areas with road salt. The severity of these issues varies, and some repairs can be quite expensive, potentially costing thousands of dollars. Regular maintenance and inspections are crucial to identify and address problems before they escalate, helping to ensure the truck’s reliability and longevity.