Noise on cold start
Asked by Bucknuts14 Mar 16, 2014 at 09:38 AM about the 2003 Volkswagen Passat GLX 4Motion
Question type: Maintenance & Repair
Recently purchased a 2003 VW Passat GLX 4 Motion for my teen driver. Have noticed
that upon a cold start the car makes an unusual noise near the front of the engine. Lasts
for only about a minute or two and then stops. Almost sounds like some type of
electronic sensor or something is warming up and then shuts off. Doesn't appear to be
coming from any belts and serpetine belt has already been replaced. Is this a normal
function on the Passat.
7 Answers
The car is 10 years old- you rule out belts- could be a bearing going out, alternator or tensioner bearing- hard to tell from here without hearing it- if the car is running ok, just run it until the noise gets louder- if it worries you, (like it should) just take it to a pro and have him/her listen- a 10 year old VW will need a good mechanic if you don't already have one
Most likely the Secondary Air Injection Pump turning on and then turning off. It runs during cold starts to lean out the rich air fuel mixture in the exhaust, which helps your cat function more efficiently.
Bucknuts14 answered 11 years ago
Thanks Armaan....the scenario you are describing makes good sense. It sounds like it something normal occurring during start up because it turns on and off within a minute of starting the engine. I would think if there were a severe issue it would continue to make the noise more frequently on start ups and last longer.
Not a problem! Yes if there was a problem it would not occur with such consistency. Enjoy the car!
I have the same problem same sound that bucknuts14 is talking about, but I have a 2014 passat Wolfsburg edition. Car only has 28000 miles. If the car is warm I don't hear the sound on start up but if it is cold I hear it until to the car is warm. Can anyone one help me?
my mechanic said it is the tensioner (cost $ 250) and if neglected it may start leaking oil.
I have the same issue and same vehicle as RoaltyVW, Could this be the secondary air injection pump armaan is talking about.
