I noticed this morning when warming up the 8 a high pitch noise coming from under the hood, anyone know what this is?

It seems to go away once warmed up.

 

6mt? Push in the clutch and the noise will go away. *shrugs* mine does it too. I figured it's just the clutch dragging in nuetral.

 

If that doesn't work, then it could be a belt squealing.. I've had this problem for a little while.. Took it to the stealership and it came back worse 0_o

Maybe air pump? Shrug!

 

If your belt sounds worse they probably tried some b.s. belt dressing.

 

It's the air pump on the passenger side under the hood.

 

If the noise happens only on cold starts, and lasts about a minute or so, Potentiated is right on the money.

 

If it is the air pump is this normal?

 

It'd be a sign of the air pump failing. But I wouldn't worry too much about it unless you need to take the car in for an emissions test while the engine is cold. The air pump's only purpose is to get the cat warmed up within X period of time. I've seen several members remove it entirely.

 

If it is the airpump, then some noise is normal.

The airpump is an electric motor that pumps, well, air..... Like any mechanical device, it is prone to failure. When they fail, they usually make abnormal noises beforehand.

The good news is that nothing bad will happen to your car if the airpump fails (other than probably blowing the fuse when the motor actually seizes).

If your car is under Emissions Warranty, the air pump is covered. Get the dealer to change it out.

 

What does the air pump do? If it's a warm up thing does it enrichen fuel by forcing in more air? Sorry motorcycle mechanic only thing I can think of. Which would explain why pulling in the clutch would kill the noise. It slightly changes the load.

 

yep, if its cold outside my airpump will make a loud noise for about 30sec. but since its been warm here lately in texas, no more noises

 

The airpump dumps fresh air into the exhaust (at the exhaust manifold) to lean the fuel mixture. This prevents unburnt fuel from saturating the cat. converter and then destroying it (or causing a fire) when the cat starts to heat. Our cars are hella-rich to get them going on cold starts.

Our transmissions are really noisy when cold. This is more of a 'rumbling', 'rocks in a dryer' sound. We tend to get used to it. When the fluid warms, it is much less noticeable.


The easy way to figure out if you have airpump noise is to unplug the power connector to the airpump before you start cold. The airpump is attached to the passenger-side shock tower.

 

So right idea just an O2 sensor style override for fuel? Because it is past the Combustion? Could they really not write the code into the startup map on the ecm? Seems counter balanced to have the ECM telling the injectors to pour in fuel and then tell them to stop because of a reading on the O2 sensor? Is there maybe more to it? Is the air being plumbed in fresh air? Therefore "technically" it's passing emissions because its fresh air and not hydrocarbons lol?