Q: Hissing noise.

asked by on December 08, 2016

my car is a bmw 320i 1988 actually.. whenever i accelerate(at low speeds).. i hear a hissing noise...note it is the same hissing noise when starting my car in the morning..i think it is a belt issue..i checked the belts, pulleys and bearings...all are fine..so i searched a bit and found out that a center bearing in the car's driveshaft may cause some hissing noise..thanks for your help

My car has 152235 miles.
My car has an automatic transmission.

This may be a sign of a vacuum leak. High idle speed, stalling and hissing sounds are common signs of a vacuum leak. When a vacuum leak is present in an engine, this causes an excessive imbalance in the air/fuel ratio which creates a loss of power and causes the motor to run at a much higher RPM as a result of the increased oxygen present in the fuel charge being injected into the motor. I would recommend having an expert from YourMechanic come to your location to diagnose your vacuum leak as these can be very difficult and time consuming to trace.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

How do I access the average speed feature?

The average speed feature tells you the average speed at which your vehicle has been traveling since the last reset. To view the average speed, press the Trip button on the steering wheel until the feature is displayed on the...

Transmission slipping while driving

The transmission in your Pontiac uses solenoids to control the shifting from one gear to the next. Typically there is a solenoid for 1st and 2nd gear, a second solenoid for 3rd and 4th gear and a 3rd and 4th...

My car keeps cutting off and jerking when i try to drive it and when i push on the gas the car moves slow make a noise and cut off

Your vehicle sounds like it is starving for fuel. If the fuel pump (https://www.yourmechanic.com/services/fuel-pump-replacement) is going bad it may make noise. The lack of power may be due to a loss of fuel pressure, mass air flow sensor (https://www.yourmechanic.com/services/mass-airflow-sensor-replacement) problem,...

Replaced calipers and brake shoes. Bled the brakes and loose clutch. Get clutch back and loose brake pressure. Why?

Hello. The symptoms you are describing are very unusual. The clutch and brake hydraulic systems on your vehicle are separate, and should function completely independently of each other. The brake master cylinder uses a completely different set of lines than...

Sometimes when Starting the car it only makes a clicking noise after a few tries to start it, it starts like nothing.

This may suggest a faulty starter solenoid. The starter solenoid is located on the starter and has internal electrical contacts that transmit electricity to the starter. When this fails, it may cause a clicking sound and will not allow the...

2012 Chevy Malibu oil change

The oil filter should not be damaged by over tightening it, however you may want to be sure that the threads on the filter were not damaged by tightening it too much as this may cause it to leak. Generally,...

No heat when idling?

Hello there, There are many faults that will cause your heater to only function at high RPM's on your 2011 Chevrolet Equinox. Given that your heat works at a high RPM or speed the most likely culprits are the radiator,...

Why is my power steering fluid bubbling up a bright orange fluid? Is that rust?

Hi there. Unfortunately, basic ATF is not the recommended power steering fluid for your 1998 Toyota Camry. The power steering fluid that is recommended for your vehicle is either Dexron II or Dexron III. It's likely that the wrong fluid...

Oil light comes on for a few seconds only when idle

If you are getting low oil pressure it would first start to show up in drive and low engine speeds. I would first suggest to have the oil and filter changed using correct oil. If problem continues then have pressure...

Related articles

Symptoms of a Bad or Failing Brake Booster Vacuum Pump
Diesel vehicles that have a stiff brake pedal with power brakes working intermittently may need to have the brake booster vacuum pump replaced.
How Long Does a Brake Booster Vacuum Sensor Last?
In In order for a car to have the brake power that it needs, there will have to be a sufficient amount of vacuum power. The engine of a car produces a good bit of vacuum power, but it will...
How Long Does a Distributor O Ring Last?
The The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then ignites the fuel and air mixture in the...