Strange intermittent noise on warm start - ‘03 vert
Thread Starter
Instructor
Joined: Dec 2006
Posts: 153
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From: Southern CA
Strange intermittent noise on warm start - ‘03 vert
I’ve been trying to figure out this strange noise (sounds like a groaning) that happens occasionally on warm starts - never on cold starts about every 6th time I start the car. Details:
- Never happens when I start it cold after sitting overnight
- happens roughly every 5th or sixth time starting warm - after the car was driven and then sat for maybe a half hour or so.
- The noise only lasts for a minute or two and then disappears.
- This has been going on for years and never gets worse.
- I’ve tried listening under the hood but it doesn’t sound like it’s coming from the front of the engine - not the alternator, not the pulleys, not the water pump. As I walk around the car it almost sounds like it’s in the exhaust but I really cannot tell where it’s actually from. I originally was thinking maybe the air pump but I’ve been told that only goes on for a couple of minutes on Cold starts and this never happens on a cold start. Also, the pump is under the driver side headlight and the sound is not coming from there nor does it sound like a high pitched whine as I’ve heard it described.
I will try to attach a recording I made to this post. Either way I’d certainly appreciate any help or ideas. The sound file is about 40 seconds and you can hear that the sound goes away at the last few seconds. This has been going on this way forever.
the car is stock.
thank you in advance,
FNS
- Never happens when I start it cold after sitting overnight
- happens roughly every 5th or sixth time starting warm - after the car was driven and then sat for maybe a half hour or so.
- The noise only lasts for a minute or two and then disappears.
- This has been going on for years and never gets worse.
- I’ve tried listening under the hood but it doesn’t sound like it’s coming from the front of the engine - not the alternator, not the pulleys, not the water pump. As I walk around the car it almost sounds like it’s in the exhaust but I really cannot tell where it’s actually from. I originally was thinking maybe the air pump but I’ve been told that only goes on for a couple of minutes on Cold starts and this never happens on a cold start. Also, the pump is under the driver side headlight and the sound is not coming from there nor does it sound like a high pitched whine as I’ve heard it described.
I will try to attach a recording I made to this post. Either way I’d certainly appreciate any help or ideas. The sound file is about 40 seconds and you can hear that the sound goes away at the last few seconds. This has been going on this way forever.
the car is stock.
thank you in advance,
FNS
Thread Starter
Instructor
Joined: Dec 2006
Posts: 153
Likes: 0
From: Southern CA
thanks but no noise from any of the front pulleys or bearings. But since you brought it up, next time I hear it I will cycle the AC on and off to see if it makes a difference. Right now AC works perfectly and no odd noises.
Thread Starter
Instructor
Joined: Dec 2006
Posts: 153
Likes: 0
From: Southern CA
I drove it tonight and it made the noise again. I turned on the AC and no difference. It makes the noise for 1-2 minutes and goes away.
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Good luck finding the source of the noise and moving this to C5 Tech for more discussion.
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Joined: Dec 2024
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From: Lancaster, KY
A mechanics stethoscope might help you isolate the noise. If not, at under $10 they might come in handy some other time:
Mechanics Stethoscope
Mechanics Stethoscope
