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Noise At Start Up Only When Av Is Cold

P

powersurg

Charter Member
Full Member
Joined
Mar 13, 2002
Messages
1,895
Location
Long Island, New York
Just recently every time I start the ave up I hear a very loud vibration noise as soon as the Ave turns other. It lasts for about 2 seconds and then goes away. I only hear it if the car has been off for awhile (like over night)
The noise sounds almost like a very thin sheet of metal vibrating. I opened up the hood but I can't get to the hood fast enough after I turn it on because it only lasts a short time.

Any Ideas

 
Hey Surge, does it sound like the valves or knocking?
Remember we had the post about the carbon buildup and i also had a post about the fuel line hitting the fire wall.
That would be 2 items to look at. My 2000 and my 2001 both started the knocking or as some call it piston slapping till about 25,000 miles.
The fuel line made a knocking noise and sounded like it was coming from the back of the dash.
Hope this helps, but you said something about vibration and i have not dealt with that yet...........
zeeya
 
irontrain said:
Hey Power heres a link to the thread zeeya was talking about Engine Noise. Hope it helps.
Click to expand...

OK I was able to get my dad to start her up while I had my head under the hood and I found out the noise is not coming from there. The noise is coming from underneath the truck. Like I said it only vibrates for about 2 seconds after I start it up and the Ave has to be cold. Could it be the Catalitic Converter? Any other ideas??? It's a very fast vibration meaning that what ever is vibrating is really getting shaken. It leads me to think that it is a thinner piece of metal due to the high pitched sound.
I looked through a lot of the noise threads and have not been able to find that much that matched.

Thanks Guys!!
 
Hey Power, I noticed a similar noise to what you are talking about on my truck. I have been having problems lately with my battery and think I only notice it when the truck has been sitting long enough that the battery is dead or close to dead. Is your truck starting ok when cold or does it seem to turnover kinda sluggish?

I am wondering if it is the electronics in the transfer case resetting. I have only heard it a couple times so not really sure, but sounds like it coming from there.
 
I have the same thing, but only on really cold mornings. It did it last winter and now again this winter. I have not had any problems with my AV so I am not worried about it. It almost sounds electrical. Like something is starting up. The motor fires up just fine so I am sure it is not the battery. But I am not a mechanic and I have been known to be wrong. Just ask my wife.
 
It's hard to tell if this is the same noise but I think I have it also. I would describe it like putting something into a fan that was spinning very fast. Kind of like a quick high pitch buzz. Mine last about a second.

I also had the exact noise in my '00 Silverado, I ever found it and I never had any trouble.

-Mark


 
nh_mark said:
It's hard to tell if this is the same noise but I think I have it also. ?I would describe it like putting something into a fan that was spinning very fast. Kind of like a quick high pitch buzz. Mine last about a second.
Click to expand...
When I start my truck cold, it makes a similar noise, almost like a kazoo. It lasts less than one second and is then quiet. (Though for the next few seconds, the engine makes a slight knocking sound. My father believes it is valvetrain noise or the hydraulic lifters. (Are those the same? I cannot remember exactly what he said and I am going by memory.))

Unfortunately, for the dealership to hear the initial sound, I would need to leave it there overnight. I will have to do it sometime once things settle down here. At least I know I am not the only one experiencing these noises.
 
Boar-Ral said:
When I start my truck cold, it makes a similar noise, almost like a kazoo....
Click to expand...

A kazoo! Thats exactly what it sounds like. lol Thanks Boar-Ral!

I don't have the knock yet but I'm sure I will. My Silverado didn't start doing that until I was around 22,000 miles.

-Mark

 
I don't know of it's the same noise as i have, and started a threat earlier about it. The noise started after having the truck for about 8 months ,and gradually got worse, the last time it was in, the noise was gettign bad enought to be able to produce, by slightly touching the gas, and having the brake on. they said it was the muffler, 2 weeks later that was replaced, and the noise is now less frequent, but still there :8:. the dealer is just tossin parts at it, but now i have to wait until it gets more frequent before i take it back,
 
I've noticed on my that sometimes (what sounds like the starter solenoid) make a noise for a split second when starting. No problems though.
 
Yes, I have this noise as well. A kazoo is exactly what it sounds like, but for only a second. The first time I heard it I thought I was grinding the starter or the starter pinion didn't retract ??? Anyways, no problem yet, so I'm crossing my fingers. Here in the GWN I hear it every time I start my car when it's cold (day or night)

Trash
 
nh_mark said:
It's hard to tell if this is the same noise but I think I have it also. ?I would describe it like putting something into a fan that was spinning very fast. Kind of like a quick high pitch buzz. Mine last about a second.

I also had the exact noise in my '00 Silverado, I ever found it and I never had any trouble. ?

-Mark
Click to expand...

Mark this is the same noiuse that I Have. Beleive it or not it is not coming from under the hood but actually under the truck. It only happens if it is very cold out and
it is the first time I start it up.
 
nh_mark said:
A kazoo! Thats exactly what it sounds like. ?lol Thanks Boar-Ral!

I don't have the knock yet but I'm sure I will. ?My Silverado didn't start doing that until I was around 22,000 miles.

-Mark
Click to expand...

22,000 miles is the exact number I have on my truck!! :6:
 
trash said:
Yes, I have this noise as well. ?A kazoo is exactly what it sounds like, but for only a second. ?The first time I heard it I thought I was grinding the starter or the starter pinion didn't retract ???? ?Anyways, no problem yet, so I'm crossing my fingers. ?Here in the GWN I hear it every time I start my car when it's cold (day or night)
Click to expand...
I need to contact my dealership and have them investigate this problem. It helps to tell them that others are experiencing the same problem, though that is not always true. The valvetrain noise that GM engines make is good proof of that. :(
 
Yep, I have the same noise too. Seems to happen when it is below 15 degrees. Sounds like a hydraulic buzzing to me. I have a feeling it is the transmission pressure regulator valve/pump thats making noise from moving the cold, thick fluid.
 
Powersurge said:
22,000 miles is the exact number I have on my truck!! ?:6:
Click to expand...

Well, mine only has 8800 mi on it, and it's making that noise when starting up. It's been f\/ckin freezin here for days on end. I was thinking it was the starter flywheel, but could be that trainy pressure valve/pump thingy :rolleyes:
 
Hey guys I have a slight power steering pump buzz at about 10 degrees lasts about 10 seconds. If you turn the wheel just a little the noise changes and then goes away. I did have fullsize jeep cherokee with the GM turbo 400 that a buzzing noise when cold but lasted about ten minutes found it had a crack in the trans filter pick up tube never made the noise again. My $0.02
 
Kazoo? I hear more of a roar. But it's gotta be the same sound because it happens just as described by everyone else. I've taken to turning the key to RUN then fastening the seat belt. In that time there's a hum that shuts off. Incidence of Kazoo has decreased, but I've no way to know if it's related.
 
empty said:
Kazoo? ?I hear more of ?a roar. ?But it's gotta be the same sound because it happens just as described by everyone else. ?I've taken to turning the key to RUN then fastening the seat belt. ?In that time there's a hum that shuts off. ?Incidence of Kazoo has decreased, but I've no way to know if it's related.
Click to expand...
Sometimes the vehicle's engine will roar when it is first started in cold weather. I do not know what causes this. Sometimes it will idle high and run at a high RPM for the first few minutes. (I've driven a few times with the engine roaring.) I believe this has something to do with the way the manual describes the engine and transmission operate when cold in an effort to warm things up faster.

As for the hum, the only thing I can think of is the fuel pump. It hums for a couple seconds when the key is first turned, but usually you cannot hear it once the engine starts.

Just my two cents. :)
 
I have two startup noises.

1: ?See THIS if you think it's a sheet metal sound. ?Mine's still doing it, and the heat shields are asking for another beating.

2: ?If it's the kazoo sound - then I tracked mine down to the power steering pump. ?Mine only does it when it's very cold, like sub 15*F. ?I have a little over 20K on the clock.

I'm not quite sure what causes it, but it happens when the pump 'engergizes' or however you want to say it, when the engine is first started. ?You can may be able to hear a "fainter" whine, like I can, when you play with the wheel a bit.
 
marc_w said:
2: ?If it's the kazoo sound - then I tracked mine down to the power steering pump. ?Mine only does it when it's very cold, like sub 15*F. ?I have a little over 20K on the clock.
Click to expand...
I will investigate this when I visit my parents over the next few days and am able to listen while someone else starts the truck. Mine starts at around the same temperature as you stated. Oddly enough, when the block heater is plugged in, it rarely makes the sound when I start it. Though lately it has started even when plugged in, but it is also about -25F outside during the day and -40F at night. Regardless, thanks for the input and I will see what I can find. :)
 
It has been real cold here for a few days, and I have noticed the Kazoo, too. Only lasts about a second on a cold start. Not too worried about it though. I also have a '91 Astro and it has done the same thing since I bought it new. Like everone else, it seems like you only hear it when it is below 20 degrees. Interesting...... >:D
 
It was 1 degree here in Indianapolis this morning with a wind chill of -17. Naturally I got the kazoo sound, however, it was a little more pronounced today.
 
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