2023 GMC SAVANA

Typical onset: 60,000-120,000 mi

Symptoms: Ticking or tapping noise from engine on cold start that persists, Check engine light with P0300-series misfire codes or P0521 oil pressure code, Sudden loss of power or rough running on one bank, Metal shavings in oil filter during routine changes

Fix: Active Fuel Management system lifters collapse, wiping out camshaft lobes and contaminating the entire lubrication system. Requires lifter replacement, camshaft, sometimes AFM delete kit installation. If caught late, you're looking at piston/ring damage from debris and need full engine rebuild or short block replacement. Labor runs 18-28 hours for full internal work depending on damage extent.

Estimated cost: $4,500-9,500

Typical onset: 40,000-80,000 mi

Symptoms: Transmission fluid pooling under vehicle near radiator area, Transmission running hot, especially under load or towing, Pink or red coolant in overflow tank if internal cooler failure, Harsh shifting or slipping after extended highway driving

Fix: The external cooler lines corrode at fittings or the internal radiator-mounted cooler develops pinhole leaks, cross-contaminating coolant and ATF. External lines are 2-3 hours; internal cooler failure requires radiator R&R, full cooling system flush, transmission flush, and filter change—8-10 hours total. If contamination goes undetected, transmission rebuild follows within 10,000 miles.

Estimated cost: $800-3,200

Typical onset: 50,000-90,000 mi

Symptoms: Vibration or shudder felt at 35-45 mph during light throttle acceleration, Feels like driving over rumble strips when converter locks up, Symptom worsens when transmission is warm, No check engine light in early stages

Fix: Torque converter clutch material degrades, causing lockup shudder. Fluid and filter service with GM-spec Mobil 1 ATF sometimes buys time (2 hours), but converter replacement is the permanent fix—requires transmission removal, 10-12 hours labor. Often paired with valve body replacement if shudder ignored too long.

Estimated cost: $600-3,800

Typical onset: 60,000-100,000 mi

Symptoms: Clunk or thud when shifting from park to drive or reverse, Excessive driveline vibration at idle in gear, Visible sag or cracking in rubber mount during inspection, Increased cabin noise from driveline

Fix: The transmission mount tears from the torque of the 6.0L and weight of cargo/towing. Straightforward replacement, 1.5-2 hours with vehicle on lift. Replace both motor mounts at same time if they're original—adds 1 hour.

Estimated cost: $300-600

Typical onset: 80,000-130,000 mi

Symptoms: Hard starting after sitting overnight, Loss of power or hesitation under acceleration, Check engine light with P0087 fuel pressure code, Fuel gauge intermittently inaccurate or stuck

Fix: The in-tank fuel pump module's plastic components deteriorate, sending debris through the system. Requires fuel tank drop, pump module replacement, and fuel filter change (often integrated into module on these). Labor is 4-5 hours. If debris reached injectors, add injector cleaning service or replacement—another 3-4 hours.

Estimated cost: $900-2,400

Symptoms: Intermittent check engine light with multiple random codes, Gauges flickering or cluster going dark momentarily, No-start condition that resolves after wiggling harness, Electrical burning smell from under hood

Fix: Main engine harness rubs against firewall or AC lines due to improper routing or missing clips, causing short circuits. Diagnosis takes 1-2 hours tracing voltage drops; repair involves harness repair, re-routing, and proper securing with OEM clips—another 2-4 hours depending on damage extent. Full harness replacement if chafing is severe runs 8-10 hours.

Estimated cost: $400-2,800

Symptoms: Transmission stuck in 3rd gear (limp mode) with no warning, Check engine light with P0700 or P2764 codes, Problem clears after key cycle but returns randomly, Occurs more often in stop-and-go traffic or extreme temperatures

Fix: TCM software calibration issue documented in GM TSB, covered by recall for some VINs. Reflash takes 1 hour at dealership with GM scan tool and subscription. Independent shops need factory access or send customer to dealer. If not recall-eligible and reflash doesn't stick, TCM replacement is 2-3 hours.

Estimated cost: $150-1,200