2002 CHEVROLET S-10

Typical onset: 120,000-180,000 mi

Symptoms: Deep knocking noise on cold start that may quiet down when warm, Metallic tapping that increases with RPM, Oil pressure drop, especially at idle, Metal shavings in oil during changes

Fix: Complete lower end rebuild or short block replacement required. 16-22 labor hours depending on 2WD vs 4WD. Rod bearings alone won't save it—mains are usually damaged too. Most shops recommend reman short block over in-chassis rebuild due to cylinder bore wear.

Estimated cost: $3,200-5,500

Typical onset: 80,000-140,000 mi

Symptoms: External coolant leak at front or rear of intake manifold, White smoke from exhaust on startup, Coolant loss with no visible external puddle, Rough idle or misfire codes from coolant entering cylinders

Fix: Upper and lower intake gaskets plus valley pan gasket. 6-8 hours labor. The composite gaskets GM used deteriorate from Dex-Cool interaction. Use Felpro premium gasket set. Often discover corroded intake bolts that snap during removal.

Estimated cost: $650-1,100

Typical onset: 100,000-160,000 mi

Symptoms: Overheating with no external leaks, White exhaust smoke and sweet smell, Coolant in oil (milky dipstick), Bubbling in coolant reservoir with engine running, Loss of power and rough running

Fix: Head gasket replacement both sides on V6, single side on I4. 10-14 hours for V6, 8-10 for I4. Always pressure-check heads for cracks and resurface. Often caused by ignored intake gasket leaks leading to overheating. Replace thermostat and water pump while in there.

Estimated cost: $1,800-2,800

Symptoms: Transmission fluid leak at radiator connections, Pink or red fluid dripping near front crossmember, Transmission slipping or delayed engagement if fluid low, Sudden large fluid loss

Fix: Steel cooler lines rust through where they connect to radiator or at body mounting points. 2-3 hours to replace both lines. Critical to catch early—if it runs low on fluid, the 4L60E will burn clutches fast. Many shops replace with rubber hose sections, but proper fix is new pre-bent steel lines.

Estimated cost: $280-500

Typical onset: 110,000-170,000 mi

Symptoms: No-start with cranking but no fuel pressure, Intermittent stalling when fuel level below 1/4 tank, Whining noise from fuel tank, Loss of power under load or uphill

Fix: In-tank pump replacement requires dropping fuel tank. 3-4 hours labor. Use AC Delco or equivalent OE-quality pump—cheap aftermarket pumps fail within a year. Check fuel filter first (inline, frame rail) before condemning pump. Filter clogs from tank rust on high-mileage trucks.

Estimated cost: $550-850

Symptoms: Visible rust perforation on frame rails behind cab, Body separation or sagging at cab mount points, Clunking over bumps from failed cab mounts, Holes visible in frame cross members

Fix: Severe in salt-belt states. Cab mount bushings rot and frame rusts underneath. Cab mount replacement is 6-8 hours (raise cab). Frame rust may be non-repairable if structural. Always inspect pre-purchase—this is the #1 scrapper of otherwise good trucks. Not cost-effective to repair if frame is compromised.

Estimated cost: $800-1,400 for cab mounts only; frame structural repair uneconomical

Typical onset: 90,000-150,000 mi

Symptoms: Hard starting especially when cold, Rough idle and hesitation, Check engine light with lean codes, Poor fuel economy

Fix: Central Sequential Fuel Injection system with poppet nozzles clogs from fuel varnish. Requires upper intake removal to access spider assembly. 5-6 hours labor. Replace entire CSFI unit, not individual poppets. Use top-tier fuel and injector cleaner as preventive.

Estimated cost: $650-950