Dmitri

Happy New Year, everyone. Welcome to the January 2013 edition of "What Sound is This?"

I'm hoping you can help me (and my dealer) identify a "chirp" or whistle sound that occurs on a cold start-up. It sounds like it's coming from the back-end of the car. I've attached a sound clip that (hopefully) allows you to hear what I'm talking about. The chirp is at the very beginning of the clip, just as I turn the key.

The dealer said that they checked all of the belts, pulleys, tensioners, water pump, etc., and couldn't find anything in the engine bay that was making this noise. I've stood outside of the car with my ear to the engine and likewise can't hear the sound. It seems like you can only hear it in the cabin.
After the car is warmed up, the car doesn't chirp again until the engine is cold. Weird.

As always, thanks for your help. Here's the clip:

sjfehr

I didn't hear anything out of the ordinary on your clip, but it's really quiet and hard to tell. You may be hearing the secondary air injection pump, which is part of the emissions system and will run for the first 30-60 seconds after the car is turned on. If this is the case, it will stop abruptly as soon as the O2 sensors are up to temp and detect the cats working.

997_rich

Your audio isn't working for me... but here's a few ideas:

-starter motor solenoid
-take the belt off and make sure it's not glazed, spin all pulleys to make sure they spin freely
-does it happen every time you start or just he first start of the day- first start of the day can be humidify+flywheel+clutch
-check especially that the water pump runs freely..
-does it happen only when it's cold out? humid out?
-does it sound like metal on metal- look closely at all the exhaust to make sure it's not scraping the engine or itself, stuff a rag in the gaps and try it again. the engine moves on first start (rubber mounts) so gaps can close.

good luck!

Dmitri

Thanks for the replies and suggestions. The sound I'm trying to isolate can be heard at between 1-2 seconds on the audio clip. A single beep or chirp.

997_Rich, the sound happens almost all of the time on a cold start, regardless of ambient conditions. It does it first thing in the morning, and if the car sits a few hours until the engine is cold, will do it again.

The dealer said that they checked pulleys, tensioner, water pump, etc and all were fine. I'm not sure about the starter solenoid. I'll have them take another look the next time I'm in. In the meantime, they've noted this in the service records just in case something catastrophic happens down the road.

Dmitri

I'm going back in to have some other work done next week, and thought I'd take another run at having the dealer figure out what this is.

I'm not sure if the clip I loaded before was any good. So, here's another clip of me starting the car twice. A double "chirp" or "beep" sound can be heard between 1-2 seconds, and a single one between 6-7 seconds.

Thanks, again, for helping to diagnose:

RennlistTomE

Doesn't sound even remotely like belts/pulleys/bearings to me.
I'd guess its electrically driven, not mechanically driven.
Could it be the fuel injection or the ABS charging?
Starter solenoid? That would typically be a loud click, not a beep. But who knows.
Some stray current hitting the alarm system just prior to the starter motor engaging?
Good luck.

At Law

I would tend to agree.

It does sound like it has its origin from the electrical side and not mechanical side.

It is very difficult to hear and diagnose. I don't believe, at first blush, that it is anything of significance.