2018 GMC Terrain Pre-Purchase Inspection Checklist
Known Issues — 2018 GMC Terrain
MODERATE
1.5L Turbo engine carbon buildup on intake valves (direct injection)
MODERATE
9-speed automatic transmission programming shudder or hesitation
MODERATE
1.6L Diesel EGR valve clogging at higher mileage
MODERATE
Infotainment system freeze requiring reboot
MODERATE
Oil consumption on 1.5T engine
MINOR
Sunroof water leak at drainage channel
What to Inspect
- Test 1.5T for carbon buildup symptoms — rough idle or hesitation
- Test 9-speed transmission for shudder under gentle acceleration
- On Diesel — scan for EGR fault codes
- Test infotainment for freeze or crash
- Check oil level after extended drive
- Inspect sunroof drainage channel
Expected Maintenance Costs
| Service | Interval | Cost |
|---|---|---|
| Oil change (synthetic) | every 7,500 miles | $60-$90 |
| Transmission fluid service | every 45,000 miles | $180-$280 |
| Spark plugs | every 60,000 miles | $120-$200 |
| Intake valve cleaning (DI engine) | every 60,000 miles | $200-$350 |
| Brake service (pads and rotors) | every 40,000 miles | $300-$450 |
| Coolant flush | every 50,000 miles | $100-$150 |
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