2.7 engine noise
12-06-2001, 02:02 PM
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2.7 engine noise
after start-up, my engine seems pretty loud, almost like there's a hole/leak in the exhaust system. it's sort of embarassing when i leave the parking garage here at work - people look at me like i'm driving a complete p.o.s. however, it goes away after a few moments (seems like once i've gained enough speed to hit second gear). is this normal for a cold start with this engine?
12-06-2001, 02:16 PM
#3
In addition to the response below...
... during the first minute, the air intake is, I believe, diverted through the heat riser. The resulting sound is kind of like the sound of a fart, heard through a long, cardboard tube.
(Sorry for the sick analogy.)
(Sorry for the sick analogy.)
12-06-2001, 02:20 PM
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secondary air pump
A pump is pumping additional air into your exhaust manifold during this period. This is necessary because the injectors are running extra rich (like a choke used to work). This warms the engine up, but the extra gas ruins emissions, so extra air is pumped into the exhaust manifold to mitigate this.
It stops after 30 seconds or something. And yes, it sounds awful. I can't imagine how Audi passes this off as something a $40K car should do, but it indeed does. Don't worry about the noise.
It stops after 30 seconds or something. And yes, it sounds awful. I can't imagine how Audi passes this off as something a $40K car should do, but it indeed does. Don't worry about the noise.
12-06-2001, 02:24 PM
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and in addition to this post . . . It is an aux pump at cold start which
will assist the engine with maintaining emissions. It is working in concert with the characteristic timcar pointed out. It could be considered loud and it also causes some to think that there is some serious lifter noise. If you open the hood you will hear the fan and the clackity clack sound.
Certainly nothing to be embarrassed about. Anyone who really cares will know exactly what the sound is and what it accomplishes.
Brian
Certainly nothing to be embarrassed about. Anyone who really cares will know exactly what the sound is and what it accomplishes.
Brian
12-06-2001, 02:52 PM
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Re: Steve is absolutely correct about the secondary air pump. The tech. pointed this out to me...
when I picked-up my car. He also said the addition air, along with the rich exhaust ratio, helps to "light off" the cats quicker for lower emissions when cold. Kind of makes sense.
Just tell people it is the fresh air fan removing any stale air from the interior of the car. Does'nt their luxury/performance sedan have one?
Or, it could be the preheater for the twin turbo's! Yeah, that's the ticket, preheater. Better yet, it is the automatic tire inflator, maintains the optimum tire pressure!!!!
Just tell people it is the fresh air fan removing any stale air from the interior of the car. Does'nt their luxury/performance sedan have one?
Or, it could be the preheater for the twin turbo's! Yeah, that's the ticket, preheater. Better yet, it is the automatic tire inflator, maintains the optimum tire pressure!!!!
