[a3massa]

Hello, recently new Cadillac CTS Vsport owner here.

I was wondering on this humming sound you get once the car shuts off, last about 10 seconds. I have read a few forums on it and have seen that it could be the wastegate valve solenoid. Is this covered under the powertrain warranty? I'm planning to take it to the dealer if it'll be covered by the factory warranty. Does anyone know what theyll be doing to diagnose it exactly?
Or if there's already a service bulletin on it that'll reference it?

I actually recently changed out the rear axle fluid and it suddenly became a bit louder too.

Let me know any links or advice you may have.

 

[kegs]

Yeah, likely the wastegate solenoids. I hear it's a pretty easy replacement if for some reason warranty doesn't cover.

 

[a3massa]

If it really is that easy or something your average person can do, is there any video links on how to do it or instruction? In case it isn't covered by my warranty since mine is a 2015 with a little over 50k on it.

 

[Denrael]

Just FYI, some dealers are now refusing to replace the wastegate solenoid under warranty for humming/buzzing, saying it's "normal". I had one replaced under B-to-B warranty a few years ago, and I now have the buzzing back on an intermittent basis. I'm not sure whether to get excited about it or not. It's about a $65 part IIRC, and yes... if you're handy at all, you can replace these (there are two, one for each turbo, but more than likely only one of them has failed). I don't know of a video showing a how-to, but at least here's a photo showing exactly where the right side solenoid is located; I'd wager the left side is in a similar location, under that cover. The second photo shows the part itself. Note that there are 3 vacuum lines that obviously need to be hooked up correctly, so pay attention as to which one goes where. BTW, this is not a "powertrain" part, as defined by GM/Cadillac, and also not part of the emission control system.

 

[a3massa]

Thanks for the feedback!! I think i could easily replace the parts myself with instruction so i may look into how to do it, if it resorts to the dealer not covering it under warranty. What system is it a part of?

 

[Denrael]

.
The parts book says "wastegate system". Here's the relevant page...

 

[martinm]

Just FYI, some dealers are now refusing to replace the wastegate solenoid under warranty for humming/buzzing, saying it's "normal". I had one replaced under B-to-B warranty a few years ago, and I now have the buzzing back on an intermittent basis. I'm not sure whether to get excited about it or not. It's about a $65 part IIRC, and yes... if you're handy at all, you can replace these (there are two, one for each turbo, but more than likely only one of them has failed). I don't know of a video showing a how-to, but at least here's a photo showing exactly where the right side solenoid is located; I'd wager the left side is in a similar location, under that cover. The second photo shows the part itself. Note that there are 3 vacuum lines that obviously need to be hooked up correctly, so pay attention as to which one goes where. BTW, this is not a "powertrain" part, as defined by GM/Cadillac, and also not part of the emission control system.


View attachment 545742
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I too have had the hummm/buzzz sound occur again after replacing the solenoids (once under warranty) and it happens when I shut down the engine, but, not every time. Question is, if replaced again by me or by the dealer (even if warranty or not) and then it comes back AGAIN, is it really a problem or is it just an annoyance and can be lived with?

I would not want this issue to cause problems with the Turbos or some other engine component to fail or be damaged and since it seems to be a recurring issue (and symptom is intermittent) does this mean they will need to be replaced as soon as this happens again to avoid further possible engine damage?

 

[Denrael]

I too have had the hummm/buzzz sound occur again after replacing the solenoids (once under warranty) and it happens when I shut down the engine, but, not every time. Question is, if replaced again by me or by the dealer (even if warranty or not) and then it comes back AGAIN, is it really a problem or is it just an annoyance and can be lived with?

I would not want this issue to cause problems with the Turbos or some other engine component to fail or be damaged and since it seems to be a recurring issue (and symptom is intermittent) does this mean they will need to be replaced as soon as this happens again to avoid further possible engine damage?

Personally, I'm not too concerned about it. This is apparently not a symptom of something bigger going wrong. I've seen literally dozens of reports of this noise occurring, but only one that had any alleged associated problems. I don't remember now the exact description of what took place (besides the noise itself) that was supposedly fixed with a solenoid replacement, but IIRC it had to do with a drivability issue only. Given the task of this solenoid in the boost control scheme, I would guess the right sort of failure *could* result in low/no/intermittent boost, for instance.

 

[Neutrocuted]

I had the noise but it only happened occasionally, I told the dealer what I had read here in the forum and they did a test and found that the valve was failing and replaced it under CPO warranty. I had no drivability issues but I want to get things done before my warranty runs out, and I think I'd better get another one before it does while it's still in great condition.

 

[martinm]

I had the noise but it only happened occasionally, I told the dealer what I had read here in the forum and they did a test and found that the valve was failing and replaced it under CPO warranty. I had no drivability issues but I want to get things done before my warranty runs out, and I think I'd better get another one before it does while it's still in great condition.

What valve are you referring to so I can mention this to the dealer next time I go in and BTW what test did they perform also? Thanks.

 

[a3massa]

Update: Just took my car into the Cadillac dealer today, discussed with the service advisor the problem and he heard/saw the noise coming from the wastegate valve. He came after to me and said it would be covered under powertrain warranty and they will be ordering the parts, should be fixed in a day or so. No trouble at all at the dealer and they provided me with a courtesy vehicle as well.

 

[Denrael]

Glad to hear... I guess some of us need to change dealers.

 

[Keith1952]

Not sure this is the same noise but I’ve been getting a whirling noise when starting the car. It will stop and then start again intermittently. CPO runs out in two months. Just heard from the dealer saying they have a service bulletin and the noise is considered normal. I asked why it hasn’t done it the previous three years and he only said it would ask the mechanic.
Any advise or comments here would be appreciated.

 

[TorontoCTSVSport]

Unfortunately, this is a "common problem" with these cars. The turbo wastegate solenoids will make this humming noise after the vehicle has been shut off. In my case it was almost always after a short but spirited drive.
It seems everyone has had different experience with dealers covering it under warranty and others claiming this is a wear item. The service departments at Cadillac dealers in my area are mediocre at best.
I bought them on RockAuto and did them myself. They're just under the plastic cover on top of the radiator and condenser.

 

[Teedoe]

Unfortunately, this is a "common problem" with these cars. The turbo wastegate solenoids will make this humming noise after the vehicle has been shut off. In my case it was almost always after a short but spirited drive.
It seems everyone has had different experience with dealers covering it under warranty and others claiming this is a wear item. The service departments at Cadillac dealers in my area are mediocre at best.
I bought them on RockAuto and did them myself. They're just under the plastic cover on top of the radiator and condenser.

How much was the part and how long did it take to replace? I'm experiencing the same issue and my dealer said that I needed to replace my turbos. Weird because I already had my turbos replaced in the past.

 

[TorontoCTSVSport]

How much was the part and how long did it take to replace? I'm experiencing the same issue and my dealer said that I needed to replace my turbos. Weird because I already had my turbos replaced in the past.

I'm in Canada and RockAuto automatically shows me pricing in CAD based on the current exchange rate. I believe I paid $68 CAD each plus DHL overnight.
The job took less than an hour total for both sides.

 

[martinm]

The part mentioned in this post: is it the same part for left and right side solenoids? I presume it is.

 

[Denrael]

Yes... see my post #6 above for the applicable parts catalog page.

 

[martinm]

Yes... see my post #6 above for the applicable parts catalog page.

Thanks Denrael.

 

[Teedoe]

Thanks Danrael


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