What is the solution for the oil light on in the Passat Lingyu?
4 Answers
A fault code 05709 was found indicating a malfunction in the oil pressure switch used to reduce oil pressure. Then, remove the brown switch and connect the oil pressure gauge, start the engine, and press the accelerator pedal. Turn off the engine, turn on the ignition switch, and clear the fault code from the engine control unit.
I was really scared last time when the oil light came on. I immediately pulled over and turned off the engine—that's common sense. I opened the hood and checked the dipstick first; if the oil level was below the minimum mark, it would be dangerous. I always keep 1 liter of oil in the trunk, so I quickly topped it up to the maximum level. After restarting, if the light was still on, there are two possibilities to consider: if the oil was just changed, the sensor plug might not be properly connected; for older cars, it’s likely due to oil pump pressure loss or excessive bearing clearance. Once on the highway, the light started flashing, and I barely made it to the exit ramp before smelling burning—turned out the engine had seized, costing 30,000 for a major overhaul! So if the light comes on, don’t push it; calling a tow truck is the safest bet. Engine repairs can cost a hundred times more than towing fees.
Veteran drivers tell you that this warning light has different levels of urgency: If it lights up at low speeds, first check the engine oil level—80% chance it's oil burning or leakage. Oil pan gasket aging and leaks are too common in Passats, and the front/rear crankshaft oil seals also tend to seep. If the light flashes or stays on during high-speed driving, you must pull over immediately—insufficient oil pressure can instantly damage the crankshaft. DIY troubleshooting in three steps: 1) Check oil level by pulling the dipstick when cold, wiping it clean, reinserting, and checking; 2) Listen for valve ticking after starting (sign of oil starvation); 3) Inspect the ground for oil stains. Repair shops provide more accurate diagnosis: Connect a pressure gauge to check if idle pressure is below 1.8 bar—if it's below 4 bar at 5000 rpm, the oil pump is toast. Never believe those shady tricks about clearing fault codes!
With twelve years of experience repairing Volkswagens, here's my advice: first turn off the AC to listen for abnormal noises. When oil is low, the oil pump will whine like a whistle. Pay special attention to the balance shaft chain tensioner in the Passat Lingyu 2.0 models—if it seizes up, it can block the oil passage. If you're handy, you can remove the oil pan to check if the oil pump screen is clogged with sludge, a common issue in older cars. I've seen cases where using low-quality oil led to sludge completely covering the screen, and the oil light was ignored for three months until the engine seized. Turbocharged engines are even more delicate—if oil pressure drops below 1.5 bar, the turbo bearings are toast. Remember these six words: Stop! Turn off! Tow!
