2000 OLDSMOBILE SILHOUETTE

Typical onset: 60,000-120,000 mi

Symptoms: White exhaust smoke on cold start, Milky oil on dipstick or oil cap, Overheating with no external leaks, Rapid coolant loss with no visible puddles, Engine misfire and rough idle as coolant floods cylinders

Fix: The Dex-Cool coolant eats the factory composite intake gaskets, dumping coolant into the crankcase. If caught early (just external seepage), gasket replacement runs 6-8 hours. If coolant mixed with oil, you're looking at complete engine teardown: bearings toast, cylinder walls scored. Requires short block or full rebuild. Many owners discover this too late because early symptoms are subtle.

Estimated cost: $800-1,200 for gaskets alone; $3,500-6,000 for engine rebuild after internal damage

Typical onset: 80,000-150,000 mi

Symptoms: Pink or strawberry milkshake appearance in coolant reservoir, Transmission slipping or no engagement, Overheating transmission, Coolant puddles near front of vehicle, Sudden transmission failure after coolant contamination

Fix: The steel cooler lines rust through where they connect to the radiator, allowing coolant and ATF to mix. Coolant in the trans destroys clutch packs and valve body within miles. If caught immediately (just seeing pink coolant), flushing and line replacement is 3-4 hours. Once the trans ingests coolant, it's 12-16 hours for rebuild or replacement. The 4T65-E doesn't survive this contamination.

Estimated cost: $400-700 for lines and flush if caught early; $2,800-4,200 for transmission rebuild/replacement after contamination

Typical onset: 70,000-130,000 mi

Symptoms: Door won't latch or close completely, Door opens while driving (dangerous), Motor runs but door doesn't move, Clicking or grinding from door mechanism, Door stuck partially open

Fix: The power door actuators wear out and cables stretch or fray. The latch mechanisms also fail, leading to doors that won't stay closed—major safety issue that spawned multiple recalls. Cable replacement is 2-3 hours per side; latch assembly is another 1.5-2 hours. Often both sides need work around the same time.

Estimated cost: $450-800 per door for cables and labor; $300-500 for latch assembly

Typical onset: 60,000-110,000 mi

Symptoms: Coolant puddle under center of engine, Steam from engine bay, Overheating in traffic, Sweet coolant smell in cabin, Coolant level drops with no external evidence

Fix: Separate from the upper intake issue, the lower manifold coolant passages also leak. This one usually leaks externally first, giving warning. Requires removing upper plenum and manifold; 5-7 hours. Do both upper and lower gaskets together when you're in there—it's foolish not to.

Estimated cost: $700-1,100 if doing lower only; add $200-300 to do both upper/lower at once

Typical onset: 90,000-140,000 mi

Symptoms: Check engine light with P0401 (insufficient EGR flow), Rough idle when warm, Hesitation on acceleration, Failed emissions test

Fix: Carbon clogs the EGR passages in the intake manifold. Cleaning requires intake removal (again). Some techs just replace the valve without cleaning passages—doesn't last. Proper fix is 4-5 hours to remove intake, clean passages, new valve.

Estimated cost: $450-750

Typical onset: 100,000-160,000 mi

Symptoms: Raw fuel smell from exhaust, Black smoke on acceleration, Poor fuel economy, Rough running and stalling, Spark plugs fouled with fuel

Fix: The regulator diaphragm splits, dumping raw fuel into the intake vacuum line. Located on the fuel rail; relatively easy access. 1.5-2 hours to replace. Sometimes damages catalytic converter from running so rich.

Estimated cost: $250-400