Chevrolet Tahoe
4.3L V6 EcoTec3 — solid base engine with 250k+ km potential. AFM deactivates two cylinders — lifters are the weak point as with all GM EcoTec3, though less affected than the 5.3L V8. Direct injection without port: valves coke from ~80k miles. Straightforward, dependable truck engine.
4.3 V6 in the Tahoe — underpowered for 5,500 lbs
285 hp in a full-size SUV: adequate daily, struggles with full load and grades. The weakest Tahoe option.
Engine Weaknesses 4
Cold start rattle from chain tensioner/guide wear.
Symptoms: Cold start rattle, P0008/P0016 codes
Cylinder deactivation wears lifters — same issue as 5.3L, but less frequent.
Symptoms: Ticking/knocking, misfires, check engine light
High-pressure fuel pump can fail — bad fuel or clogged filters accelerate wear.
Symptoms: Hard cold start, stalling, power loss, engine hesitation
Direct injection without port spray: intake valves carbon up from ~80k miles. Walnut blasting cleans but doesn't prevent reoccurrence. Regular oil changes slow the process.
Symptoms: Rough idle, power loss from ~80k miles, engine hesitation
Vehicle Weaknesses 3
Vacuum pump no longer builds pressure — hard brake pedal, significantly longer stopping distance.
Compressor and air springs fail — vehicle sags. Replacing all four at once recommended.
Same 8L90 issue as Silverado.