1999 BUICK RIVIERA

Typical onset: 80,000-140,000 mi

Symptoms: Pink or strawberry milkshake-colored fluid in coolant reservoir, Transmission slipping or delayed engagement after engine reaches operating temp, Coolant in transmission pan during fluid changes, Overheating transmission with burnt ATF smell

Fix: The internal transmission cooler in the radiator fails, allowing coolant and ATF to mix. Coolant destroys clutch packs and solenoids in the 4T65-E. Requires radiator replacement, transmission flush if caught early (2-3 hrs), or complete transmission rebuild/replacement if contamination progressed (8-12 hrs labor for R&R plus rebuild). This is THE killer on these cars—many owners discover it too late.

Estimated cost: $400-800 if caught immediately with flush, $2,500-4,200 for transmission replacement with reman unit

Typical onset: 90,000-130,000 mi

Symptoms: Whining or grinding noise from front of engine that increases with RPM, Loss of boost pressure and power, Squealing on cold starts, Visible oil weeping from supercharger snout

Fix: The rubber coupler between the supercharger and drive pulley deteriorates, and the front bearing fails. Requires supercharger removal, coupler replacement, and often snout bearing service. 4-6 hours labor. Aftermarket upgraded couplers available and recommended.

Estimated cost: $600-1,200

Typical onset: 70,000-110,000 mi

Symptoms: Coolant seepage visible below intake manifold at block mating surface, Gradual coolant loss with no external leak visible from above, Occasional rough idle when gasket failure is severe, Coolant smell from engine bay after shutdown

Fix: The plastic lower intake manifold gaskets degrade and leak coolant externally (less commonly internally). Requires removal of upper plenum, fuel rails, and associated components. Critical to replace both upper and lower gaskets, coolant elbows, and inspect thermostat housing. 5-7 hours labor.

Estimated cost: $650-1,100

Typical onset: 60,000-120,000 mi

Symptoms: Power windows move slowly or only in one direction, Grinding or clicking from door when operating window, Window drops into door or sits crooked in channel, Complete failure to move with motor running

Fix: The plastic window regulator mechanisms and motors fail, particularly driver and front passenger. Requires door panel removal and regulator/motor assembly replacement. 2-3 hours per door.

Estimated cost: $350-600 per door

Typical onset: 80,000-150,000 mi

Symptoms: No-start condition with cranking but no firing, Intermittent stalling, especially when hot, Engine dies while driving and won't restart until cooled, No tach reading during crank

Fix: The crank sensor behind the harmonic balancer fails due to heat cycling. Requires removal of serpentine belt, balancer, and sometimes power steering pump for access. 2-3 hours labor. Always replace the connector pigtail if corroded.

Estimated cost: $250-450

Typical onset: 90,000-140,000 mi

Symptoms: Excessive engine/transmission movement during shifts, Clunking when shifting from park to drive or reverse, Vibration at idle in gear, Visible sagging of powertrain when inspected from below

Fix: The rubber transmission mount deteriorates, especially with fluid contamination from the cooler failures. Requires supporting powertrain and mount replacement. Often done with engine mounts simultaneously. 1.5-2.5 hours.

Estimated cost: $200-400