2003 Passat GLS Wagon emits loud hissing sound

Asked by Jul 23, 2010 at 10:25 PM about the 2003 Volkswagen Passat GLS Wagon

Question type: Maintenance & Repair

The sound sounds like high pressured air being released like the air brakes on a tractor trailer, but it goes on for 4 or 5 seconds. It only happens when I start to drive after the car has been fully cooled down. The loud hissing stars after I have driven about 25 yards. What's going on?

1 Answer

35

This is most likely the SAP or (Secondary Air Pump). All VW/Audi cars have the same pump which was installed for emissions starting somewhere in the 90's. On the "newer" ones, the rivets break loose and the pump begins to leak and become VERY loud in some cases. The pump will only turn on immediately when you start the vehicle after it has been parked overnight and it will come on from time to time until the car is fully warmed up. NOrmally it is quiet and you can barely hear or feel it running. All it does is send unburt gas vapors through the intake pipe to make sure they get burned up. THe cost for replacement is high at a mechanic. If you have a few hours and can do the work yourself, check out this VW FORUM SITE for the Do It Yourself. VWVORTEX.COM/Forums. I have fixed one of these pumps and it was very easy to drill out the rivets and reseal the sucker with bolts and locktight. Just getting to the pump and replacing it was the long part. Good luck.

3 of 3 people found this helpful.

Your Answer

Volkswagen Passat Experts

  • #1
    tenspeed
    Reputation
    1,340
  • #2
    Tom Demyan
    Reputation
    1,260
  • #3
    Chrisand Edwards
    Reputation
    1,200
View All

Related Models For Sale

Used Volkswagen Jetta
598 Great Deals out of 36,385 listings starting at $1,000
Used Honda Accord
1,098 Great Deals out of 61,485 listings starting at $999
Used Toyota Camry
1,055 Great Deals out of 71,326 listings starting at $295
Used Audi A4
281 Great Deals out of 11,295 listings starting at $1,999
Used BMW 3 Series
1,133 Great Deals out of 33,037 listings starting at $1,000
Used Honda Civic
825 Great Deals out of 72,772 listings starting at $1,000
Used Nissan Altima
1,043 Great Deals out of 75,008 listings starting at $1,200
Used Volkswagen Touareg
56 Great Deals out of 2,489 listings starting at $2,900
Used Volkswagen Golf
102 Great Deals out of 5,098 listings starting at $1,950
Used Volkswagen GTI
135 Great Deals out of 8,640 listings starting at $2,400
Used Hyundai Sonata
714 Great Deals out of 49,892 listings starting at $790
Used Chevrolet Malibu
1,123 Great Deals out of 71,678 listings starting at $1,896

Used Cars For Sale

2017 Volkswagen Passat For Sale
16 Great Deals out of 9,720 listings starting at $13,647
2016 Volkswagen Passat For Sale
49 Great Deals out of 1,460 listings starting at $10,792
2015 Volkswagen Passat For Sale
129 Great Deals out of 2,755 listings starting at $6,999
2014 Volkswagen Passat For Sale
81 Great Deals out of 1,912 listings starting at $6,995
2013 Volkswagen Passat For Sale
55 Great Deals out of 1,559 listings starting at $5,995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.