1990 GMC P6000

The 1990 GMC P6000 is a heavy-duty pickup truck that was available with a variety of engine and transmission options. Some of the most popular engine options included the 6.2L diesel V8, the 7.4L gasoline V8, and the 8.1L gasoline V8. Transmission options included a 4-speed automatic, a 5-speed manual, and a 6-speed manual.

People who own the 1990 GMC P6000 generally like its powerful engines, rugged construction, and spacious interior. However, some owners have reported issues with the vehicle’s reliability, particularly with the engine and transmission.

Engine

6.2L Diesel V8

• Fuel Injector Failure: Symptoms include difficulty starting, rough idling, and a loss of power. The solution is to replace the faulty fuel injectors. Estimated cost to fix: $400 - $800+
• Turbocharger Failure: Symptoms include a loss of power, increased exhaust smoke, and a whistling noise. The solution is to replace the turbocharger. Estimated cost to fix: $1,000 - $2,000+

7.4L Gasoline V8

• Intake Manifold Gasket Failure: Symptoms include coolant leaks, overheating, and a loss of power. The solution is to replace the intake manifold gasket. Estimated cost to fix: $300 - $500+
• Distributor Failure: Symptoms include difficulty starting, rough idling, and a loss of power. The solution is to replace the distributor. Estimated cost to fix: $200 - $400+

8.1L Gasoline V8

• Connecting Rod Bearing Failure: Symptoms include a knocking noise from the engine, a loss of power, and eventually engine seizure. The solution is to replace the connecting rod bearings. Estimated cost to fix: $2,000 - $4,000+
• Valve Seat Recession: Symptoms include a loss of power, increased oil consumption, and blue exhaust smoke. The solution is to replace the valve seats. Estimated cost to fix: $1,500 - $2,500+

Transmission

4-Speed Automatic

• Torque Converter Failure: Symptoms include slipping, shuddering, and a loss of power. The solution is to replace the torque converter. Estimated cost to fix: $1,000 - $1,500+
• Transmission Control Module Failure: Symptoms include erratic shifting, refusal to shift, and a loss of power. The solution is to replace the transmission control module. Estimated cost to fix: $300 - $500+

5-Speed Manual

• Synchronizer Failure: Symptoms include difficulty shifting gears, grinding noises, and a loss of power. The solution is to replace the synchronizers. Estimated cost to fix: $500 - $800+
• Clutch Failure: Symptoms include a slipping clutch, difficulty shifting gears, and a burning smell. The solution is to replace the clutch. Estimated cost to fix: $400 - $600+

6-Speed Manual

• Input Shaft Bearing Failure: Symptoms include a grinding noise from the transmission, difficulty shifting gears, and a loss of power. The solution is to replace the input shaft bearing. Estimated cost to fix: $600 - $1,000+
• Counter Shaft Failure: Symptoms include a whining noise from the transmission, difficulty shifting gears, and a loss of power. The solution is to replace the counter shaft. Estimated cost to fix: $1,200 - $1,800+

Suspension

• Leaf Spring Failure: Symptoms include sagging rear end, uneven tire wear, and a rough ride. The solution is to replace the leaf springs. Estimated cost to fix: $500 - $800+
• Shock Absorber Failure: Symptoms include a rough ride, excessive body roll, and poor handling. The solution is to replace the shock absorbers. Estimated cost to fix: $300 - $500+

Electrical

• Alternator Failure: Symptoms include dim headlights, a dead battery, and a warning light on the dashboard. The solution is to replace the alternator. Estimated cost to fix: $300 - $500+
• Starter Failure: Symptoms include difficulty starting the engine, a clicking noise, or no noise at all. The solution is to replace the starter. Estimated cost to fix: $200 - $400+

Exterior

• Rust: Symptoms include bubbling paint, rust spots, and holes in the body panels. The solution is to repair or replace the affected areas. Estimated cost to fix: Varies widely depending on the extent of the damage.
• Headlight Failure: Symptoms include dim or flickering headlights. The solution is to replace the headlight bulbs. Estimated cost to fix: $50 - $100+

Interior

• Dashboard Cracking: Symptoms include cracks in the dashboard. The solution is to replace the dashboard. Estimated cost to fix: $500 - $800+
• Seat Upholstery Ripping: Symptoms include tears or holes in the seat upholstery. The solution is to repair or replace the upholstery. Estimated cost to fix: $200 - $400+

Summary

The 1990 GMC P6000 is a powerful and rugged truck, but it is not without its problems. The most common issues affect the engine, transmission, and suspension. Some of these issues can be expensive to fix, so it is important to factor in the cost of potential repairs when considering purchasing this vehicle.