So far I'm loving my "new to me" 2001 Boxster. While I've owned two before, this one is just different enough to have me wondering about a few things. Most seem like non-issue things that I can work with (rattles, especially), but there are a couple of noises that have me a little nervous.

One is a slight induction howl coming out of the passenger side vent. It happens very rarely, and only when I'm trying to hold 30mph in the neighborhood. If I lift throttle it goes away. (..which is why I'm guessing it's an induction howl..)

The other I noticed only this morning when I started the car. There was quite a wine coming from that back of the car. It only lasted a few seconds and I never heard it the rest of my drive. I'll keep an ear out for it in case it was just "something weird". But Julie drove the car yesterday and mentioned a similar noise. I thought she was talking about the induction howl, but maybe she was talking about this? Hmm...

Anyway, anybody have any thoughts on these? The car is certified so any fixes would be done under warranty, but I want to be pro-active if this is something that will leave me stranded on the road somewhere!

Thanks.

 

THE NOISE ON STARTING IS PROBALY YOUR SECODNARY AIR PUMP, AND MOST LIKELY NORMAL

WHAT DO U MEAN BY AND "INDUCTION" HOWL

 

Cool, thanks.

I'm driving along in the neighborhood, holding it steady at about 30 mph, and all of the sudden there's a slight howl/wine coming from the passenger side...it sounds like it's coming out of the side vent, but I guess it could be coming from anywhere. It almost sounds like some kind of resonance. Anyway, if I lift the throttle, it goes away. It might come back, but goes away anytime I adjust the throttle. I never hear it anywhere else than in the neighborhood when I'm trying to hold a steady (slow) speed. I notice no other effects on the car when it happens. Just the annoying sound.

 

I thought your "interesting noise" was going to be a voice saying.. "get a base Cayman.. get a base Cayman" .

 

..do you hear those too?!?!?

 

I hear a sorta howling noise at low speed followed by a clunk, then nothing.

Happens at low speed, sometimes but always while running the AC.
Mine turned out to be the venting valves in the air conditioning ducting under the dash.

 

only recently

 

OK, I posted the same Qs on the Pelican Board and got this about my "induction howl": It appears to be my air-oil separator. AFJuvat on the Pelican board suggested I remove the oil cap with the motor running and put my hand over the filler. If you feel a vacuum, the air-oil separator is bad and needs to be replaced. I did that and felt a vacuum. Very slight but it's there. Fortunately, that one is covered under certified warranty (it doesn't look like an easy replacement), so I'll be making an appt. very soon!

Here's that link, btw: http://forums.pelicanparts.com/showt...hreadid=304333

Cheers!

 

I just did a write-up on how to change the air/oil seperator and the difference between the new and old ones. They are known to go bad,but thankfully a new one and the "accordian"/"j" tube are only $110 shipped. Shot me a email at gl-g100rcd@sbcglobal.net if you would like the write-up w/ pictures.

My secondary air pump "whines" as well. Shuts off after the car has warm up some and stays off. Does your's sound almost like a high-pitched vacuum?

 

SECONDARY AIR PUMPS ARE NOISEY THATS THE WAY THEY ARE AS LONG AS ITS WORKING DONT WORRY ABOUT IT. YOU WILL ALWAYS HAVE SOME VACUM AT THE OIL FILL CAP THATS NORMAL.

 

there is also the engine compartment exhaust fan that will turn on and off depending on engine compartment temperature, I notice it mostly when stuck in traffic but it will turn on whenever it needs to

it also turns on when the car is off, I heard it twice this summer in the garage too

the only thing is, it's got nothing to do with engine speed so it's probably not what you hear

 

As 99firehawk says if the vacuum is light, then it's working/normal. If you can't pull the cap off because the vacuum is so high, then it's time to replace. I did have a leak in my oil fill tube which is not as common as the AOS, but you might want to check for any oil dripping in that area. The part is even cheaper than the AOS ($20?), but it is a serious PITA to replace.

I've noticed some other kind of high-pitched sqeal/moan on mine, but otherwise mine is pretty noise free, so can't help ya there. I think my noise is some sort of gas tank vapor recovery or something because it only does it for a couple seconds when shutting off the engine on a really hot day. It sounds like the system is purging/equalizing itself. The air intake is on the driver's (left) side, while the air pump is on the right (IIRC).

 

That's exactly what it sounds like. But it goes away very quickly...almost as quickly as the car settles to idle. So it sounds like that's not a big problem. Good!

 

Hmm...well then it looks like I probably don't have a problem. The vacuum is very light. Noticable, but it's not like it pulls my skin or leaves a mark when I put my hand over the oil fill. I have no problem getting the cap off and back on again.

Thanks for the second opinion. The car did just have a 30k service as well as a bit of other work done to bring it up to certification spec, so I think I'm going to go with "it's not a problem" right now. I'll keep checking and see if it gets any worse. Sound like a plan?

 

Maybe after a few more times, you'll be able to localize where the noise is coming from.

From what I've read on air/oil separator failures (since I thought I was having one), there are a few failure modes. In one, they fail and oil gets sucked into the air intake manifolds followed by massive plumes of oil smoke. In this case, the advice I've read is to obviously shut the engine off so you don't contaminate the cats and/or cause an oil hydro-lock (which seems like it would have to be a really massive oil intake to me). Another type of failure I've read is that it fails, but the car can still run but the crankcase (and oil fill tube) are under huge vacuum. I think somewhere I've read the oil fill tube is under so much vacuum, it collapses flat. In another partial failure mode, it just smokes a lot and the intake is puddling with oil. Some oil is normal from the oil vapor (hence the separator). There may be other failure modes, and this is all 3rd hand regurgitated info, but I think yours (and mine) is OK.

One thing I would do is to (carefully) put the car up in the air and take a good look around for any signs of dripping or leaks. Just because you don't see anything on the floor is not an all clear sign since someone could have wiped/cleaned everything up. My oil fill tube leak probably took a couple years to accumulate enough oil to dribble down the various panels and hoses and collect and start dripping. I figure it's good to go hunting with a flashlight as long as it's under warranty.

Enjoy as I'm sure you already are!