2004 Passat standard

My son just bought a 2004 Passat V6 with a standard tranny. It seems to make a humming noise of some type and doesn’t sound like an engine noise. I’m thinking it might be that the transmission is making this noise. The car has 50k miles. Just wondering if this is a normal noise for this car. Not really loud, but somewhat annoying. Thanks for any replies.

Could it be the tires?

It’s not normal for a transmission to make a humming noise. Check the level of the transmission oil or fluid and make sure it’s correct.

Thanks, I’ll check that. Not sure if it’s the tranny, but I’ll check everything out. It can’t be the tires because it makes the humming sound standing still. It even makes it when the car is not in gear and clutch pedal is not depressed.

Does it stop when you step on the clutch pedal?

No, it seems like a pretty consistent noise as you’re standing still or driving through the gears. It doesn’t seem like an engine noise (no knocking etc.).

If the noise exists while sitting at a stand-still, then you can rule out the tires and the transmission.

Even though you don’t think that the engine is the source of the noise, eliminating the tires and the transmission from the equation makes it almost definite that the engine is the source of the noise.

I’m wondering if it could be belts or something like that. It doesn’t sound like metal on metal. Thanks.

Can you tell where the noise is coming from? One suspect might be the fuel pump if the noise seems to be coming from the rer of he car where the gas tank is. A leak in the exhaust system might make such a noise.

Does the noise change from idle(not in gear) if you rev the engine? As you said it did not change from standing still. It could be a heat shield on the catalytic converter. It only sounds really metallic after half of the welds go. before that it can be a loud humm. If the pitch of the noise rises with engine rpm in park/neutral then it is a engine/exauhst issue. Could be a belt system bearing a whole bunch of steps to find out which part of the car it comes from. Can you hear the same hum by getting out and opening the engine compartment?