2007 CHEVROLET TAHOE

Typical onset: 100,000-180,000 mi

Symptoms: rough idle especially when cold, ticking or tapping from engine, excessive oil consumption (quart every 500-1000 mi), misfire codes on cylinders 1 and/or 7, metal shavings in oil

Fix: AFM lifters collapse and cause cam lobe wear; piston rings fail from oil starvation. Fix requires full AFM delete with new cam, lifters, and pushrods (12-18 hours), or if rings are gone, short block replacement (20-28 hours). Many shops now recommend preemptive AFM disable kit around 100k to avoid catastrophic failure.

Estimated cost: $2,800-4,500 for AFM delete; $5,500-8,000 for short block

Typical onset: 80,000-150,000 mi

Symptoms: transmission fluid looks pink and foamy, coolant appears milky or pink, transmission slipping or delayed engagement, overheating transmission, coolant loss with no external leaks

Fix: Internal radiator failure allows coolant and ATF to mix, destroying the transmission. Requires new radiator, complete transmission flush or rebuild if contamination went too far (6-10 hours for flush and radiator; 16-22 hours if trans needs rebuild). External cooler upgrade is essential to prevent repeat failure.

Estimated cost: $800-1,400 if caught early; $3,200-5,000 with transmission rebuild

Typical onset: 90,000-140,000 mi

Symptoms: gauges read erratically or drop to zero intermittently, speedometer bouncing or not working, no-start with no crank (but battery good), PRNDL indicator issues, StabiliTrak and ABS lights on randomly

Fix: Stepper motors in cluster fail and body control module (BCM) develops solder joint issues. Cluster can be rebuilt by specialists (mail-in service, 1-2 hour R&R) or replaced with programmed unit. BCM requires dealer or high-end scanner to program (2-3 hours diag and replacement).

Estimated cost: $350-650 for cluster rebuild; $800-1,200 for BCM replacement

Typical onset: 120,000+ mi in salt states; varies by climate

Symptoms: brake fluid leaking near rear axle or under body, fuel smell under vehicle, soft brake pedal, visible rust on exposed lines

Fix: GMT900 trucks have poorly-coated steel brake and fuel lines that rot from the inside out, especially in rust belt. Full brake line replacement from master cylinder to rear axle (6-9 hours); fuel lines from tank to engine (5-8 hours). Many shops now use pre-bent stainless kits.

Estimated cost: $900-1,500 for brake lines; $700-1,200 for fuel lines

Typical onset: 80,000-120,000 mi

Symptoms: coolant leak from front of engine, whining or grinding noise from accessory belt area, overheating, visible coolant seepage at weep hole

Fix: GM water pumps on 5.3L typically fail around 100k, sometimes catastrophically if bearing seizes. Replacement is straightforward (2.5-3.5 hours). Use OE AC Delco pump; aftermarket failures are common within a year.

Estimated cost: $400-650

Typical onset: 70,000-130,000 mi

Symptoms: service 4WD message on dash, inability to shift into or out of 4WD, grinding when engaging 4WD, 4WD indicator lights flashing

Fix: Encoder motor on transfer case fails or selector switch on dash goes bad. Encoder motor replacement is easy (1-1.5 hours); dash switch requires cluster removal (2-2.5 hours). Occasionally requires transfer case fluid service if internal issue.

Estimated cost: $250-450 for encoder motor; $300-500 for dash switch

Typical onset: 90,000-150,000 mi

Symptoms: ticking noise from engine bay on cold start that fades when warm, exhaust smell in cabin, visible soot near manifold, check engine light with bank lean codes

Fix: Exhaust manifold bolts corrode and snap, creating exhaust leaks. Requires manifold removal and drilling out broken studs (4-6 hours per side). Use upgraded stainless hardware on reassembly to prevent repeat.

Estimated cost: $600-1,000 per side