I don't know if any of you have experienced this, but the dealer says they have no solution and it is driving me crazy and it has done it since new!

When I am driving down the interstate at about 75-80 there is a sound that is coming from the front drivers side that sounds like someone is chasing me and blowing their horn. It happens at random and is not continuous. It is as if maybe the wind hits something and creates this sound. All I know is I have to turn up the radio to hide the noise it is so bad - and even that doesn't muffle it out all the way. The service manager has driven the car and has heard the sound, but has provided no solution. Any input would be greatly appreciated.

is it like a whistling/vibrating high pitched sound?

if so mine does that and its a 2001, i thought it may have had something to do with the moonroof, its at high speeds as well and wind directions affects it also, hmmm

I had a 2000, 2002, and a 2004 and none of those made the noise. I don't feel any vibration in the car at all - It drives like a dream! The only way I can describe it is that someone is blowing their horn, if i roll down the window I don't hear it from the outside. But, that might be because of the wind muffles it out. I can only hear it from inside the car. It doesn't do it all the time, more so than not. I guess it is a wind thing - I just don't know why my DTS seems to be the only one that makes the noise. Anyway - this is a good place to vent.

06 DTS. We are hearing a weird noise too. It sounds as if it is coming from some part of the front of the car, also at around 70 mph. There is no message being displayed. It is a buzzing sound and it comes and goes. I tried opening and closing the sun roof. This did not seem to make any difference. We will be contacting the dealer to see if they have any answers. This car has a lot of good features and nice ride, but there are some weird quirks. They problems take the fun out of driving this car!! We have still not had a fix for the downhill inadvertent accelerating problem. I have a post about this. When going down a steep grade the car accelerates with your foot of the gas peddle and requires constant braking!!
wps

Hey man...I havent experienced that problem...the only problem on my 06 dts performance is that randomly...so far 6 times, as i come to a stop a weird knocking noise comes from the back, as if there is someone in the trunk! I took it to the dealer and they have not been able to recreate the noise...do any of you have that problem? I will look into your problem as well...

I don't know if any of you have experienced this, but the dealer says they have no solution and it is driving me crazy and it has done it since new!

When I am driving down the interstate at about 75-80 there is a sound that is coming from the front drivers side that sounds like someone is chasing me and blowing their horn. It happens at random and is not continuous. It is as if maybe the wind hits something and creates this sound. All I know is I have to turn up the radio to hide the noise it is so bad - and even that doesn't muffle it out all the way. The service manager has driven the car and has heard the sound, but has provided no solution. Any input would be greatly appreciated.

mkcad,
My wife just took delivery of "06 DTS II with same problem. Service mgr' has ridden in and driven the car and comfirmed the noise. He thinkd it's associated with the air dam driecting air to the radiator. He is going to get the car in the shop tomorrow ann try to find the source and correct. Will keep forum up dated on our results.
Bfaught

Hey man...I havent experienced that problem...the only problem on my 06 dts performance is that randomly...so far 6 times, as i come to a stop a weird knocking noise comes from the back, as if there is someone in the trunk! I took it to the dealer and they have not been able to recreate the noise...do any of you have that problem? I will look into your problem as well...

I've got the same knocking noise! When stopping, I get about 6 rapid knocks from the right rear. The first time it did it, I thought someone was knocking on the trunk to get my attention! Mine's an '06 with about 4500 miles, and I've had the knocking occur about 10 times.

I rented a 06 dts on a trip in florida and heard the noise coming from the sunroof at 90mph. Opened the roof andit went away.

mkcad,
My wife just took delivery of "06 DTS II with same problem. Service mgr' has ridden in and driven the car and comfirmed the noise. He thinkd it's associated with the air dam driecting air to the radiator. He is going to get the car in the shop tomorrow ann try to find the source and correct. Will keep forum up dated on our results.
Bfaught

Good information, it might help us get rid of the noise too. Thanks, wps

I have just passed 5K miles on my 2006 DTS. I have the same noise in the front drivers area when on the Interstate around 80 mph. Husband says it sounds like a loud Lionel Train whistle. I have also had the knocking in the trunk area upon slowing down to stop. A bit relieved to know I am not alone on this. Thanks for all of your postings.

I have the same problem with my new 2006 DTS Lux II. In my case, the noise is similar to a car horn blowing, although at a lower volume. To me, there is no question that it is wind/speed related. I first noticed it occasionally between 70-75MPH, and generally, only for the first 10 minutes of driving (maybe something gets warm and then quiets?).

But last weekend, I was returning to central NY from Boston, with a significant (30MPH) headwind and it was rather unbearable. Also, when I was behind another car it was less or non-existent, convincing me it is related to air blowing through the engine compartment.

I will be getting it into the dealer soon.

When I am driving down the interstate at about 75-80 there is a sound that is coming from the front drivers side that sounds like someone is chasing me and blowing their horn

Hmmm... Check your door fits on the driver side. Sometimes if the rear door header is outboard of the front door header it will make a noise at certain speeds/wind conditions.

Hope this helps!

the only problem on my 06 dts performance is that randomly...so far 6 times, as i come to a stop a weird knocking noise comes from the back, as if there is someone in the trunk!

This noise is coming from the fuel evap canister solenoid when it performs a purge cycle. It can be somewhat alarming I know, as it does sound like someone could possibly be in the trunk. :-) It is, however, a normal function of the system.

I've got the same knocking noise! When stopping, I get about 6 rapid knocks from the right rear. The first time it did it, I thought someone was knocking on the trunk to get my attention! Mine's an '06 with about 4500 miles, and I've had the knocking occur about 10 times.

Have you figured out or heard of any solutions! I took my monte carlo in for servicing and walked over and to the cadillac service manager and asked him...he said there is nothing yet in regards to noises like that...

I had experienced the horn blowing sound on several occasions and then I finally realized it was coming from the XM radio station I was listening to. There is more than one station that has this sound as well as some others

Oddly enough, I haven't had the sound lately. But if you read my prior post, there is no chance it was the XM radio or a door seal. It was definitely something related to air moving underneath or through the hood/engine compartment. Still haven't gotten it to the dealer, especially since it's non-existent now.

:) I had a Buick with the same noise. It turned out to be the rubber weather stripping at the front of the passenger door going into oscillation at certain speeds. I think they re-glued the gasket and re-aligned the door for a tighter fit.

I don't know if any of you have experienced this, but the dealer says they have no solution and it is driving me crazy and it has done it since new!

When I am driving down the interstate at about 75-80 there is a sound that is coming from the front drivers side that sounds like someone is chasing me and blowing their horn. It happens at random and is not continuous. It is as if maybe the wind hits something and creates this sound. All I know is I have to turn up the radio to hide the noise it is so bad - and even that doesn't muffle it out all the way. The service manager has driven the car and has heard the sound, but has provided no solution. Any input would be greatly appreciated.

Reply to mkcad weird noise – 10-1-06:
We took the car in for service the other day. The master technician had not heard of the weird noise. I think I have fixed it. We have had the car up to around 75 several times since fixing the plastic. Raise the hood, there is a latch below on the vehicle. On both side of the latch there is plastic. This plastic is vibrating at higher speeds causing the sound. I used silicone sealer under the leading edge of this plastic to glue it down. If this plastic ever needs to be removed it should come off without too much of a problem.. Apparently this plastic is not loose on all of these vehicles, not everyone is hearing this noise.

The noise in the trunk:
Not sure if this will help all the complaints, but these vehicles have a vacuum pump in the trunk. If the intake vacuum in the engine becomes low this pump will run to bring vacuum to a proper amount. If the pump is running excessively you could have a vacuum leak. It is common to hear this pump right after you start the engine and it is at idle, also if you stop with the transmission in gear and the engine running at idle. If this pump is loose it could be radiating the noise, it is a small vacuum pump.
wps
Still no fix for the acceleration problem, see 2006 Cadillac DTS downhill inadvertent acceleration problem

I also have similar noise sporadically at when idling or stop with the transmission in gear . It's like a ding noise at very low volume .However I don't think that's a problem conversely I like it .
Another sound comes on on and off when I all the way stop with D .It's only happening at the stop not when idling .
I guess , those noises are same for STS as well .

Hey man...I havent experienced that problem...the only problem on my 06 dts performance is that randomly...so far 6 times, as i come to a stop a weird knocking noise comes from the back, as if there is someone in the trunk! I took it to the dealer and they have not been able to recreate the noise...do any of you have that problem? I will look into your problem as well...
There is a Service Bulletin on this. They say it is a part of the warm up of the cat converter that causes five pulse surges in the exhaust. In my 2006DTS it only occurs when the engine starts at ambient temperatures below 60F and when the temp gage passes 8 o'clock, i.e. one line below horizontal. I think I may have a loose baffle as I get a clear tapping sound when it happens. Have not tried to demonstrate tapping noise as I would need to leave it overnight in the fall (cold outdoor temperature) and go in without anyone their starting it to move it etc. Will let you know if we get more information later this month.

I had the same issue - I replaced the bottom air dam cowling ($190) and the issue went away, I damaged it on a high curb at a parking lot...

I didn't notice the noise, until I sat in the front passenger seat and it seemed every time my wife hit a bump, I could hear a "thump" from the passenger side trunk area.

I just had the right rear shock replaced at the dealership and it took care of the problem.

I have the same high pitched noise at 70-74 mph. Dealer has heard the noise but has no solution. I do not have a sun roof so that is not the problem. It is really maddening when driving long distances. Has anyone yet found an answer to this problem?

There is a Service Bulletin on this. They say it is a part of the warm up of the cat converter that causes five pulse surges in the exhaust. In my 2006DTS it only occurs when the engine starts at ambient temperatures below 60F and when the temp gage passes 8 o'clock, i.e. one line below horizontal. I think I may have a loose baffle as I get a clear tapping sound when it happens. Have not tried to demonstrate tapping noise as I would need to leave it overnight in the fall (cold outdoor temperature) and go in without anyone their starting it to move it etc. Will let you know if we get more information later this month.

I took mine to the dealer and listed this as a problem since it has happened 4 or 5 times to me. They just play Mickey the Mope and say there are no service bullitens and they couldn't dupliate the failure. As far as I can tell, if they don't hear the failure they will not take your word for it and apply the fix if there is one. I hope there is one because I have never had a car that had to pass gas like this in the morning. Now the issue is, how do you get them to bevieve anything an owner says. It's hard to explain why a you would be so tolerant to put up with a $50,000 plus car sounds like a thumping piece of tin. It also shoots your credibility to hell when you argue for the quality of American cars.

I have had same "horn" noise on my 06 ~~~ Serv. Tec. put masking tape around outside windshield ,presto it was gone ~~ He then had to reseal W/s I have the pecking noise also, so far haven't figured that one out.

Hey man...I havent experienced that problem...the only problem on my 06 dts performance is that randomly...so far 6 times, as i come to a stop a weird knocking noise comes from the back, as if there is someone in the trunk! I took it to the dealer and they have not been able to recreate the noise...do any of you have that problem? I will look into your problem as well...
my 06 DTS does exactly the samne thing, and often at the same light, only whenthe car has been driven less than 2-3 miles and today it did it while drving through the same stop light rather than when I am stopped at that light. Usuually though it does it when I stop at a light. Knocks four times, sometimes with an extra knock a few moments later. The kids in the back seat says that it is coming from under th afloor board although it sounds like the trunk from where I am sitting.

have you been able to discover anything yet? I haven't taken mine in yet because it only has 2K miles and is not easily reproducable.

Hey man...I havent experienced that problem...the only problem on my 06 dts performance is that randomly...so far 6 times, as i come to a stop a weird knocking noise comes from the back, as if there is someone in the trunk! I took it to the dealer and they have not been able to recreate the noise...do any of you have that problem? I will look into your problem as well...

My 06 has done it several times but not enough that I could tell you any specifics of the time or temp. A very clear knocking sound as if someone were in the trunk. Since it's happened to others, guess I won't bother to take it in to be checked out. Kinda creepy though first time or two it happens.

My 06 has done it several times but not enough that I could tell you any specifics of the time or temp. A very clear knocking sound as if someone were in the trunk. Since it's happened to others, guess I won't bother to take it in to be checked out. Kinda creepy though first time or two it happens.

Please don't accept this stupid noise just because it has happened to others. The noise isn't normal and $20,000 cars don't do it. We sound just like Cadillac service when we say that other cars fail the same way as ours so ours must be normal.

I just bought a 2006 DTS and we took it to Vegas this last week and we have that same noise.

Any luck on finding out what on getting it fixed and finding out what was making the noise ?

Thanks

I have to ask you which noise you are referring to -- the "thumps" in the trunk or the "train horn" in the front?

I took the my car in last month and mentioned the thumps in the trunk - and the dealership gathered up some loose golf balls and some bottled water and secured them under my netting. I guess I did not describe the sound right.

I have caught up on the thread and yes, my trunk thumps happen a certain distance from home when I first take the car out for the day. And, yes, sometimes I get 5 thumps followed by a delayed sixth thump. Most of the time just 5 thumps in a row. Frankly, I hated to mention it to the dealership -- and now that I have I don't feel like I will bother with it again.

As for the "train" sound in front when going fast -- I haven't heard it for quite a while. Next time I do -- I will take better notes and get more details.

Sorry -- no help to you on either sound. But am still interested in which sound you are hearing.-- MJ

Sorry....I should have been a bit clearer.

I'm interested in the "horn noise" coming from the front area. I get the same "horn noise" that was described when driving at 70-80mph. Doesn’t happen all the time……but it happens enough to try and get it fixed.

Please let me know if anyone has had it diagnosed and repaired.

Thanks
Brian

One of my Tauruses used to do that. I can't remember if it was the wipers, or the chrome on top of windshield. Google it; certainly, other people are finding that too.

Google it....I did. That's how I found this forum and thread.

Since I'm unable to send messages to anyone until I get more then 20 posts.

I would like to ask any of you if you wouldn’t mind sending a message to MKCaddy, who started this thread to see if he's gotten his "horn like noise" issue resolved. Even after taking this thread into the dealer, they still haven’t been able to isolate the noise and I'm hoping someone on here has had better luck in getting it fixed.

It's way too nice of a car to give up on.

Any help would be greatly appreciated.

Thanks
Brian

Ok....this is the deal. These cars have had multipule problems with noises....the most comon is the wind rush around the mirrors and the windshield. What I have seen is it seems that whatever sits the windshield on the car is placing it to far right or left causing a wind noise. The only fix is replacing the windshield. Take it to your local dealer and take a test drive with the shop foreman or the service manager......If they are at a small dealership they might not have seen this problem yet or the volume of cars as larger dealers.

For some crazy reason, after about 8,000 miles I have not heard the sound at all. I guess it fixed itself. I would have taken it back to the dealer, but did not have time. Now when I get my monthly email from onstar with my diagnostic report, they claim something is majorly wrong with my OnStar system and I need to get to a dealer immediately. The funny thing is that my OnStar system works great, I used it yesterday.

Update on "Train Whistle" Noise

Well, I still have it, and I never took it to the dealer, assuming all I would get is the usual runaround. Previously, I always thought it sounded like it was coming from the engine compartment, but the last few times I heard it, I now believe it is the sunroof. Go figure. It was just because that's where it seems to be coming from, and when I vented the sunroof, it stopped. However, it destroys what I wanted the car for... absolutre silence and comfort when on the highway.

There are two consistent aspects about it:
1. I never hear it during the winter (I am in upstate NY)
2. I almost always hear it when the teperature is 85+ and I get to about 75 MPH

I am about to drive to Maine in 10 days and the thought of listening to this for 7-8 hours has me worried.

I don't know if any of you have experienced this, but the dealer says they have no solution and it is driving me crazy and it has done it since new!

When I am driving down the interstate at about 75-80 there is a sound that is coming from the front drivers side that sounds like someone is chasing me and blowing their horn. It happens at random and is not continuous. It is as if maybe the wind hits something and creates this sound. All I know is I have to turn up the radio to hide the noise it is so bad - and even that doesn't muffle it out all the way. The service manager has driven the car and has heard the sound, but has provided no solution. Any input would be greatly appreciated.

96 or 99 Taurus had similar problem. Either wipers or windshield trim (top) was source of problem. I can't remember which.

You could try some duct tape over one of those areas. Process of elimination.