High Pitched Whine (Not Rear End) - Page 3

ssmith100 · #31 (**permalink**) 01-12-07, 10:35 PM

James,

Only when moving but can start as low as 20mph. Sometimes the pitch of the noise will change. You can be driving down the highway at 80mph and it will have been doing it for 10 minutes straight and then just stop, it may start again in another 10 miles. Sometimes if I come to a stop and it's been doing it if I get on the car pretty hard it will stop. It's the craziest thing.

It sounds like a fuel pump but not that loud. Sometimes it's very faint and sometimes it's extremely loud.

Shane

**Florian** · #32 (**permalink**) 01-13-07, 12:11 AM

Quote:

Originally Posted by ssmith100

James,

Only when moving but can start as low as 20mph. Sometimes the pitch of the noise will change. You can be driving down the highway at 80mph and it will have been doing it for 10 minutes straight and then just stop, it may start again in another 10 miles. Sometimes if I come to a stop and it's been doing it if I get on the car pretty hard it will stop. It's the craziest thing.

It sounds like a fuel pump but not that loud. Sometimes it's very faint and sometimes it's extremely loud.

Shane

Shane, thats absolutely the issue I have. Exactly the same.

F

ssmith100 · #33 (**permalink**) 01-13-07, 12:24 AM

I sure wish you could find the answer Flo. I'm about to lose my mind over this.

Shane

Rich H · #34 (**permalink**) 01-13-07, 12:34 AM

After looking at the diagram of the half shaft I think my problem could be one of the CV joints. The noise cycles (warbles) at about the same frequency as the revolution speed of the joint and it sounds like a dry metal against metal rubbing noise. I'll have the dealer check it out.

keeksv · #35 (**permalink**) 01-13-07, 09:59 AM

Quote:

Originally Posted by Rich H

After looking at the diagram of the half shaft I think my problem could be one of the CV joints. The noise cycles (warbles) at about the same frequency as the revolution speed of the joint and it sounds like a dry metal against metal rubbing noise. I'll have the dealer check it out.

**Florian** · #36 (**permalink**) 01-13-07, 02:11 PM

Quote:

Originally Posted by ssmith100

I sure wish you could find the answer Flo. I'm about to lose my mind over this.

Shane

Doug will find the issue and cure it in the next few weeks. Pix to follow later.

F

bbmurphy1 · #37 (**permalink**) 01-16-07, 02:21 AM

I am having the very same problem... I actually logged on tonight to see if anyone else is having this problem. And to see if there is a correction. With my car I notice the noise at around 42 mph only when I am light on the gas pedal. You know, giving it enough gas just to stay at that speed. Its very annoying. Haven't wanted to part from my V for a couple of days to leave it at the dealer. But I am real close.

**Florian** · #38 (**permalink**) 01-16-07, 06:26 PM

you got the standard rear end whine.....

F

Kels55 · #39 (**permalink**) 02-08-07, 02:50 PM

I had a similar problem that I described as a hissing sound that increases as the speed increases. Have you noticed any blowing or sucking sounds from the gas tank when you fill up? I did during one fill up that I did during the 2 months that this sound was occurring, but it only happened once. I thought it must be a vaccum line or fuel filter/pump but this is what happened when I took my car for service.

Comment 13 at this link:

http://www.cadillacforums.com/forums...light=gas+tank

Now, granted, what my final mechanic is saying about my problem may have been caused by pressure built up in the tank but I won't know for sure until I get it replaced and see for myself.

I would recommend that you make sure your dealership checks you gas tank and fuel pump and make sure that it isn't creating pressure in your tank.

**ctsvett** · #40 (**permalink**) 02-09-07, 11:48 PM

There was an A/C or heater tube whine from a long time ago... Might want to check that... Search the FAQ or the forum... If you cant find it.. PM me

Reed

ssmith100 · #41 (**permalink**) 03-27-07, 01:01 PM

*********************UPDATE*********************** *

Resurected this thread as my car is going into the shop. My "whine" has gotten to the point it isn't tolerable anymore. I have found out on thing though that has lead me to believe it is not drivetrain related. Three times now when my car has reached half a tank of gas the whine has started. It will still come and go at times but does get worse as the tank gets lower. If I fill my tank.....................no whine. I'm on my second day of fill up and still no whine. I have thought from the beginning that it sounded like the fuel pump so hopefully the repair will pertain to something in the fuel system. I'll keep you guys updated.

Shane

ssmith100 · #42 (**permalink**) 05-16-07, 12:37 PM

Resurrected Again.

Not fuel related. Car going back in the shop as the whine is almost continuous now. Told them to keep it till it's fixed. Not Happy

Shane

ewill3rd · #43 (**permalink**) 05-16-07, 09:23 PM

It sounds to me like you might have some fuel pump issues.

First of all you say it is a high pitched whine?
Axles, rear ends, CV joints, and wheel bearings usually make growling noises (with the exception of the whine from the gears when they get messed up in the diff)
They are more low pitched and change directly with vehicle speed.

If the noise stays constant over a large speed range it is probably something that is not so speed related.
I believe the CTS-V uses a returnless fuel system, which means the pressure regulator is in the tank and it is designed to maintain a constant fuel pressure throughout the full range of vehicle operation.
The "load" will change on the pump though, because higher demand means higher fuel volume and the pump tone can change based on engine load, and often does.
In fact, some cars use a separate fuel pump control module to increase or decrease the speed of the pump based on several factors including load and vehicle speed. I don't think the V uses that, but based on your description I think the noise may be eminating from the fuel pump.

It is indeed inside the tank, on the right side of the car. There is also a separate sender with a "jet pump" in it on the left side of the tank that transfers fuel from left to right because of the tank design. (saddle for drivetrain)

Based on what I have read so far I'd say you are looking at a fuel pump issue, although it may not be a failing part, it may be something you just happened to notice and now you are fixated on it.
At any rate there are a few tricks you can try to isolate the problem.

Get the vehicle up to speed until you hear it, put the car in neutral and turn off the key. Things like bearings, axles, etc, will keep making noise because they are still turning. Load sensitive noises may disappear.
When you are done you can restart the car and just put it back in whatever gear feels right for the speed you are going.
Be sure to do this when traffic is clear, you have lots of room and there are no hazards around.
The pump may run for a couple seconds after key off but if it hums and then stops then it is probably the pump.

HTH.
Let me know if you have more comments or questions.

ewill3rd · #44 (**permalink**) 05-16-07, 09:25 PM

The fact that it is fuel level related, or seems to be points even more strongly to the pump.

Why do you say it is not "fuel related"?

ssmith100 · #45 (**permalink**) 05-17-07, 10:07 AM

HTH,

Everything you said makes since and originally I thought it was pump related. I would notice that after I filled my car up the noise would go away after a while and then as the car used gas it would come more frequent. "Possible fuel pump related" After a few fill ups I then started to notice that even after fill up it would do it. It sure does sound like what your talking about though. I'm going to try shutting the car down like you said next time it does it. That should help verify it.

Thanks,
Shane