2001 BUICK LESABRE

Typical onset: 80,000-150,000 mi

Symptoms: Coolant loss with no visible leaks, White exhaust smoke on startup, Milky oil or coolant in oil, Engine overheating if neglected, Sweet smell from exhaust

Fix: The plastic lower intake manifold gaskets deteriorate and allow coolant into the crankcase or cylinders. Requires removal of upper plenum and intake, replacement with updated metal-reinforced gaskets (Felpro MS98000T kit standard). If caught early, 4-6 hours labor. If driven too long with coolant-contaminated oil, you're looking at bearing damage, requiring short block or full rebuild.

Estimated cost: $600-1,200 (gaskets only), $3,500-6,000 (if engine damage occurred)

Typical onset: 100,000-180,000 mi

Symptoms: Transmission fluid leak near radiator, Pink fluid under vehicle, Transmission slipping or delayed engagement, Coolant in transmission or transmission fluid in coolant (cross-contamination)

Fix: The cooler lines rust through where they connect to the radiator, or the internal cooler in the radiator fails, mixing coolant and ATF. External line replacement is 1.5-2 hours. If cross-contamination occurred, the transmission must be flushed multiple times or rebuilt—ATF in coolant destroys seals, coolant in trans destroys clutches. Many shops recommend transmission replacement after contamination.

Estimated cost: $250-500 (lines only), $1,800-3,500 (if transmission contaminated/rebuild needed)

Typical onset: 120,000-200,000 mi

Symptoms: Harsh or delayed 1-2 shift, Slipping in 2nd or 3rd gear under load, No reverse or intermittent reverse, Burnt transmission fluid smell, Check engine light with transmission codes

Fix: The 4T65-E has known issues with 2nd gear clutch pack wear and pressure control solenoid failures. Also prone to input shaft bearing failure. Rebuild takes 8-12 hours at a transmission shop, but many opt for reman units due to parts availability and warranty. Fluid changes every 50k can delay but not prevent this.

Estimated cost: $1,800-3,200

Typical onset: 100,000-160,000 mi

Symptoms: No start or extended cranking, Stalling when fuel tank below 1/4, Whining noise from rear seat area, Loss of power under acceleration, Engine stumbling at highway speeds

Fix: The in-tank pump fails from wear or contamination. Requires dropping the fuel tank (no access door on this model). 2-3 hours labor. Replace fuel filter at the same time—it's inline under the vehicle and often neglected, contributing to pump failure.

Estimated cost: $400-700

Typical onset: 80,000-140,000 mi

Symptoms: Clunk when shifting from Park to Drive or Reverse, Vibration at idle in gear, Excessive engine movement visible when accelerating, Harsh engagement into gear

Fix: The upper and lower transmission mounts deteriorate from age and oil exposure. Simple replacement, but requires supporting the powertrain. Upper mount 1 hour, lower 1.5-2 hours if done separately. Do both while you're in there.

Estimated cost: $200-450

Typical onset: 100,000-150,000 mi

Symptoms: Battery light on, Dim headlights at idle, Electrical accessories weak or failing, No start with new battery, Whining or grinding noise from front of engine

Fix: The Nippondenso alternators are decent but fail from bearing wear or regulator issues. Common to see voltage regulator go first, causing overcharging (14.8V+) or undercharging. Replacement is straightforward, 1-1.5 hours. Use quality reman with warranty.

Estimated cost: $300-550

Typical onset: 90,000-160,000 mi

Symptoms: Power steering fluid leak on ground, Whining noise when turning, Stiff steering when fluid low, Visible fluid on hose near pump or rack

Fix: The high-pressure hose develops cracks or leaks at crimped fittings from age and heat cycles. Replacement is 1-1.5 hours, but tight quarters near exhaust manifold make it tedious. Inspect both pressure and return lines at same time.

Estimated cost: $200-400