Car Talk #2211: Rattling Shifters, Engine Steam Cleaning, and Lug Nut Patterns

Car Maintenance Myths and Realities

• 💡 Steam cleaning engines is not a scam, but it's generally unnecessary unless the engine is extremely dirty or there's an oil leak being diagnosed.
• 💰 Save your money; a clean engine doesn't necessarily perform better, and it's not recommended for resale value as it's a tactic used by used car salespeople.

The Science of Tightening Lug Nuts

• 🎯 The star-shaped pattern for tightening lug nuts is crucial to ensure the wheel seats evenly onto the hub, preventing it from becoming cocked.
• 🛠️ Tighten lug nuts snugly in a star pattern, then go around again to fully tighten them once the wheel is on the ground, ensuring the wheel is straight and securely attached.
• 🚗 Forgetting to tighten lug nuts after changing a tire can be extremely dangerous, leading to wheel detachment.

Diagnosing Car Noises and Stalling

• ⚠️ A knocking sound when applying brakes, even if mechanics can't find an issue, could indicate a warped brake disc, causing pads to move. While not immediately dangerous, it can be annoying and worsen over time.
• 🚗 A 1969 Mustang stalling when cold but running well when warm is likely due to incorrect ignition timing, especially if the points and condenser have been replaced but timing hasn't been checked with a timing light.
• ⚙️ A rattling shift lever, especially in cold weather, is often caused by worn shifter bushings that allow the entire stick to vibrate; a temporary fix might involve finding a way to dampen the vibration, like hanging something on it.

Puzzler Corner

• 🧩 The weekly puzzler involves a man and his son in a Suzuki Samurai rollover. The twist is when the doctor at the hospital says, "My son," referring to the boy, leading to the question of how this is possible if the father was also injured.
• 💡 The solution to the puzzler hinges on the doctor being the boy's mother, a common riddle that plays on assumptions about gender roles.