Skip the auto shop - Our mechanics make house calls

Q: Car has hissing sound when initially accelerating

asked by on

I have been searching a long time for a solution and hope that you can help me. There is a hissing sound whenever I accelerate. The hissing occurs only in the initial phase of the acceleration. I can not detect from where it is originating. The volume also changes and sometimes it is louder than other times. Another item of concern is that sometimes my car feels sluggish, but other times it feels light and powerful. Do you know what is causing this hissing and the sluggishness?

A: Hi there, thanks for writing in about your ...

Hi there, thanks for writing in about your 2006 Porsche Cayman. Generally, a hissing noise will come from a leaking vacuum source or something like an exhaust manifold gasket. The vacuum leak will cause some performance issues as the engine computers have a hard time regulating fuel delivery. If you would like to have this checked, a certified expert from YourMechanic can inspect the noise and perform any needed repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: SUV moves too slowly in reverse and when accelerating; dull clump sound in Drive

The reason you cannot move very fast in the reverse setting is you have an internal leak in the transmission valve body. The clunk is the valve body moving back the other way, and the clunk is the transmission engaging....

Q: Shifter cable broke in heavy traffic on highway

There are a lot of inquiries regarding a similar issue with vehicles of your year and model. The linkage connection is made of plastic and will eventually break. A metal safety clip or an extra tie may be used to...

Q: Car will not shift when lights on on

Hi Ford Freestyle owner: What you're describing sounds a lot like an electrical problem as opposed to being mechanical. When the wrench and check engine light both illuminate at the same time, something in the ECU is typically not happy...

Related articles

How to Renew Your Car Registration in Oklahoma(DELETED)
Having your car registered with the Oklahoma Tax Commission is an important part of driving legally in this state. You will need to do this within 30 days of moving to Oklahoma...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...