Making whistle noise on off on run and stopping.
There are basically two types of whistle noises.
* Whistle when you get more gas (increase RPM, put gas pedal, sometimes just idling but louder when you put more gas)
This usually intake-side leak.
Intake manifold itself, intake manifold gasket (most likely), even airfilter housing, Airflow meter housing (connector), anything where air goes to engine.
usually engine get rough or unstable idle when intake leak occur.
Engine knocking or pinging may feel.
* Whistle when you decrease RPM (engine brake, reduce speed, sometimes just idling but louder when it dropping RPM)
This usually Vacuum-side leak.
There are many vacuum hoses in engine room. even inside of cabin (heater control, etc)
Try to spot where it coming from.
Vacuum also connected to Brake servo, heater control and spark timing.
Put metal or plastic pipe (small PVC pipe will work fine) to one of your ear then isolate source of noise and find where it come from.
Feb 26, 2016 |
Cars & Trucks