Very low pitched dentist drill noise.....

[2k1audiS4]

Yup, I think my drivers side is making a low boost(1-3psi), low pitched dentist drill noise. Its very faint. You can only hear it when the windows are up and the radio is off at low speed and psi. I thought it might be my cv joint and axel because i need to replace them but it def sounds like it is fluctuating with the boost. The car still pulls like a train and holds boost fine. Could there be anything else making this noise or is it only a matter of time before I am looking at a junk drivers side turbo? I am asking now because I have a chance to buy a real cheap silver 2000 s4 6speed on tuesday. I wasnt even considering buying it before the drill noise but now it might be an option because i dont have the cash to go stg3 right now. If I got the 2000 I would just wholesale my car at a dealer auction "as-is" and use that money to pay for the 2000. I think I could do an even swap but I would be going from a 2001.5 sport to a 2000 non-sport. What do you guys think.

I would not have the funds to go stg3 for at least a year. So thats really not an option.

[tike0rz]

Cmon dude you know better than to have a B5 S4 and not have a nest egg just in case the turbo lady comes! Shame on you.

I wouldn't go for the 2000. It may have more problems than your current car, you never know. I'd baby the 01.5 if I were you and keep it out of boost until I had the funds, or close to it. Its near impossible, but thats probably your best bet, financially.

[gointoscott]

How many minles on the car? Personally I woudlnt worry about the noise. A turbo car will whistle as it boosts. So its hard to say based on what you said. I think sometimes we overreact because of seeing posts from others on these forums talking about turbo's going.

I think its too hard to say how long it will be before it goes.

About buying the car and swapping turbos. I also wouldnt ever put used turbo's in. How do you know the condition of the turbo's of the car you are buying? If you have to go through hassle of pulling motor to replace turbo's Do it right the first time.

Again unless you have a million miles on the car, I woudlnt worry about it and just cross that road when it comes.

[2k1audiS4]

How many minles on the car? Personally I woudlnt worry about the noise. A turbo car will whistle as it boosts. So its hard to say based on what you said. I think sometimes we overreact because of seeing posts from others on these forums talking about turbo's going.

I think its too hard to say how long it will be before it goes.

About buying the car and swapping turbos. I also wouldnt ever put used turbo's in. How do you know the condition of the turbo's of the car you are buying? If you have to go through hassle of pulling motor to replace turbo's Do it right the first time.

Again unless you have a million miles on the car, I woudlnt worry about it and just cross that road when it comes.

Yea I wasnt saying I was going to swap the turbos I was saying I am just going to sell the 01.5 and drive the 00. The 01.5 has 138,500 miles on it.

[alias747]

Yea I wasnt saying I was going to swap the turbos I was saying I am just going to sell the 01.5 and drive the 00. The 01.5 has 138,500 miles on it.

Ha, yeah I think you are running on borrowed time with those snails if they are original. But then again, there have been people with more miles than that on originals and they run just fine. Are you sure that the noise isn't just a small boost leak somewhere? That can cause a high pitch whine noise similar to that when you are first going into boost. I would check that out before you go do something crazy.

[highPSI-S4]

i thought you only here the dentist drill during moderate to high boost and that at low boost a low whistle during spool up is normal.

[2k1audiS4]

i thought you only here the dentist drill during moderate to high boost and that at low boost a low whistle during spool up is normal.

Yea I know the whistle and its def not the normal whistle. It might be a boost leak but then i would think I wouldnt hit 19psi on my spike anymore. Im not sure when your supposed to hear the dentist drill but I cant seem to get it to make the noise anywhere past 3psi. When I let off the gas and the boost goes back to 20vac I can hear the noise like its a diverter valve. But I only have about 1,000miles on my new 710n's.

[Kruat]

I've had a noise similar to that for at least 25k miles. Mine happens at low RPM, under load, with light boost. Sometimes it happens, sometimes it doesn't. My car has 115k and has the stock turbos. And I agree, it's not the normal turbo whistle. It sounds more labored almost...not quite as free spinning as a normal turbo whistle. Mine even sounds as if it has a rattle to it. I was worried quite a bit once I first heard it, but it's been running fine for the last year and half. Normal boost and car still pulls hard. So i dunno...

[alias747]

I've basically learned to not sit and worry about my turbos. Sometimes I convince myself that my normal spool up sound doesn't sound right and it means my turbos or going to explode into heaping balls of flames. But then I decided that I am just not going to fret becuase all that is going to do is turn my hair gray. Screw it, if they blow, they blow.

[Matt@JHM]

I've heard that noise before. Happens with about 3 PSI. And WOT it is completely clean, no abnormal sounds. I've been told that it could just be the DV's fluctuating slightly and creating a humming sound.

[highPSI-S4]

I've heard that noise before. Happens with about 3 PSI. And WOT it is completely clean, no abnormal sounds. I've been told that it could just be the DV's fluctuating slightly and creating a humming sound.

I think i know what you meen. at like 3psi when i shift it's like a whooo-oouuu sound. like a low cow moo. right

[obijohn22]

for what it's worth, I had a fan clutch make a very similar noise, and i thought it was a turbo. could really hear it at mild throttle and idle. a mechanics steth. will help make sure it is turbo noise.

[LIFES4]

hmm i got the same sound but only when im going past 60mph. its kinda werid and i still dont know what it is.

[S4-ORCE]

Pressure test, I bet its a boost leak

[Matt@JHM]

I think i know what you meen. at like 3psi when i shift it's like a whooo-oouuu sound. like a low cow moo. right

Yep, exactly.

[AudiSportB5S4]

I've heard that noise before. Happens with about 3 PSI. And WOT it is completely clean, no abnormal sounds. I've been told that it could just be the DV's fluctuating slightly and creating a humming sound.

exactly. its the Diverter valves.. NO worry!

[2k1audiS4]

exactly. its the Diverter valves.. NO worry!

If thats the case I would be the happiest man alive.

[AudiSportB5S4]

If thats the case I would be the happiest man alive.

lol, dont get too happy these cars sense it and then shit on you! haha.

[S4 in_lowplaces]

your paranoid, chill...

[rick_chicago]

Does the noise minimize once oil temps get into the range (180-210)?

I have the same issue you describe, but it gets much quieter once temps are up (which also pretty much guarantees it's the turbo). I have heard enough to know it's shaft play.

I would never swap a 01.5 sport that you know well for a 00 that you don't, even with questionable turbos.