Testing an Engine Oil Cleaner and Fuel Additive on Two Cars

Volkswagen GTI Engine Noise and Carbon Buildup

• 🚗 The Volkswagen GTI exhibits significant engine noise due to carbon buildup, which affects lubrication and can lead to rattling and oil burning.
• 💡 Modern engines use lower-tension piston rings for better gas mileage, but this can cause them to seal less effectively and stick when oil clogs, leading to oil consumption.
• 🧪 A new engine oil cleaner product is tested to address carbon buildup, with the process involving running the engine at a fast idle for 15 minutes before an oil and filter change.
• ⚠️ The presence of engine oil fumes in the exhaust indicates worn piston rings and a less-than-perfect engine seal.

GMC Terrain Diagnostic and Fuel System Issues

• 🚗 A 2014 GMC Terrain with 146,000 miles is experiencing code problems, running lean, and hesitating on cold starts.
• 🛠️ Initial diagnosis reveals multiple trouble codes, including issues with the brake booster pump motor and fuel system rich codes (P0172, P0175).
• 💰 The owner previously spent money at a dealer for a fuel pressure regulator replacement, which did not fix the problem.
• 🔍 The vehicle has a V6 direct injection engine, and despite its age and mileage, it shows signs of wear, including fading headlights and worn seats.

Fuel Cleaner Test and Results

• 🧪 Bernie's fuel cleaner (505 CRF ATS chemical fuel cleaner) is added to the GMC Terrain's gas tank after checking the air filter, which was found to be clean.
• 📈 The vehicle is taken for a road test, driving at higher RPMs in lower gears to maximize the cleaner's effectiveness.
• ✅ After an hour of driving with the cleaner, a subsequent scan shows no trouble codes, and the fuel trim data indicates the engine is no longer running rich.
• 💡 The cleaner is credited with cleaning the fuel injectors, resolving the dribbling issue and improving the spray pattern, which in turn corrected the fuel system rich codes.
• ⚠️ The summary notes that GDI systems do not clean intake valves directly, as only air passes through them, and fuel is injected directly into the cylinder.