Any ideas? Last couple of times I drove the car I noticed upon start up a hissing sound like air escaping from something. If I open the hatch It seems like it's coming from the left side of the engine bay.

When I come back from the ride and open up the hood the sound is gone. Any ideas what it could be?

 

maybe its a snake.

that would explain why the sound is gone after your ride

 

DOes the car stumble at idle?

Vaccum leak? Hose off of the valve cover area or PCV system somewhere?

 

Chris, do you have a aftermarket intake or filter element? It is often louder after installing these.

Any loss in boost pressure at WOT or CEL's? Give your intercooler hoses and Y pipe a good shake as it goes into the TB (although at idle there shouldn't be much air flow in these.)

 

i get the same sound at a cold start. usually it stops when the car is warmed up and ready to go.

 

Bob, no aftermarket intake or filter. No CEL's either. Haven't checked for differences in boost but car seems to be running fine.

 

Any update.. i have heard the same thing recently..

 

dealer said it's fine.

 

totally normal, airpump throws air into the exhaust at startup to reduce hydrocarbons.

 

I had a similar problem (intercooler hoses loose). In hard acceleration the hoses couldn't keep up with the pressure and just disconnected. the engine kept shutting down, but once all the hoses were all done rght, it was perfect again. I think in you case if the dealer said its fine, shouldn't be a problem, but I would check for a tear in the hoses.

 

Bingo! Secondary air pump. Pumps extra air into exhaust until the cats heat up sufficiently, done to reduce emissions as the engine does not run as efficiently on cold starts.

 

yes what you thinking

 

Sounds like the hose off but not thare but sounds like pic or some ware about passat back motor area

 

Valve cover area or hose backvthare

 

Alot of air like air hose off air compressor Amor air loud hissing forme thare