Today I heard aprotracted siren noisewhile driving my 2002 Blazer . Ithappened as I exited the PA turnpike after athree hour drive.The gauges all looked OK. As I rounded the loop of the exit, I heard a siren-like noise which sounded like it was coming out of the radio or to the right. I pulled over to see if I had a flat tire. There were no raised areas of paving to cause the noise. As I pulled into the toll booth, the attendant **noticed** the noise. Just after exiting I pulled over and phoned the repair shop to see if I should have the car towed. I opted to drive it about 20 minutes more to reach the shop.

The noise does not occur while idling.It begins as a very low but loud noise, and goes up in pitch as the car accelerates, then returns to the lower pitch as the car slows down, then stops when the car isnot moving. I think there was some vibration while the noise was happening but it was difficult to concentrate.

The shop managerdrove the car out but it didn't perform the siren noise. Another employee then drove it and there was about a 7 second very loud siren noise.I am certain everyone on the road hears this noise. It's similar to some firehouse sirens.

I did look at other posts but was not sure the noise mentioned was loud. One would almost think a police car was generating the noise.

Thanks for your thoughts on this matter. I will direct the manager to pursueyour suggestionsas the car remains in the shop.

 

You've already got the truck in the shop. Let's see what they find. Telling them what to look for, or what you think the problem might be, is like telling a doctor what's wrong with you without letting him diagnose. If you take a vehicle to a shop, it's best to tell them what is happening and let them find the problem.
That being said, after they tell you what they find, post back up and let us know.

 

The car is back at home. Thanks to another post here,I discovered theproblemappears to have been the vacuum hose under the battery tray. The old part looked faultyaccording to the service manager.I mentioned the post from this forum.

Rriddle3, I have torespectfully disagree with youradviceaboutkeeping quiet if you have a suggestion. After looking on the GM site, themechanics couldn't find anything abouta siren noise.It is a Chevy dealer as well, so the problem seems not to be widespread as they had no other customer reporting such a noise. They thought it could be the 4 wheel drive issue.It seems thenewer models have an electronicpart instead of the part that failed on my car.

As far as medical diagnoses ,I haveexperiencedgreat benefitsfrom speaking up.

Should the siren sound return, I will re-post about it.
Thanks.

 

Are you sure it wasnt sure a loose belt or perhaps something else ? Alternator.

 

i have seen this happen before..the idler pulley bearing is going bad, just a thought

 

I've heard that exact same sound in the past on other vehicles, never my blazer. Sadly, it turned out to be the police.

 

Lmao!!..