What Causes the Zizzing Sound When Accelerating in a Volvo?
2 Answers
Reasons for the zizzing sound when accelerating in a Volvo: 1. Air intake pipe perforation or air leakage: Many modern vehicles use engineering plastics for their intake pipes. When the intake pipe ages, it may develop air leaks, resulting in a zizzing noise during acceleration. 2. Excessive or loose valve clearance: Valves can also wear out. When the wear reaches a certain level, the valve clearance becomes too large, causing a zizzing sound as air passes through the valves. 3. Dirty engine oil: Engine oil serves as a lubricant, but when it hasn't been changed for a long time, it accumulates contaminants. This leads to insufficient lubrication of the engine, resulting in abnormal noises.
Last year, I helped my neighbor fix a speed-related abnormal noise issue with their Volvo. That S90 had a noticeable hissing sound during acceleration, resembling air leakage or friction. The most likely cause was a leak in the intake system. Volvo cars often come with turbochargers, and loose connections or aged hoses can produce this kind of sound when pressure increases, similar to the sound of sucking through a straw. It could also be due to aging exhaust manifold gaskets leaking air, which tends to make more noise during vibrations. If such a fault isn’t repaired promptly, the engine may start shaking, affecting handling and increasing fuel consumption. I recommend not delaying and taking it to a professional shop to check vacuum pressure with a scanner. This prevents minor issues from becoming major ones, and usually, replacing a small component will solve the problem.
