Cadillac Owners Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
My 2012 Cadillac CTS all wheel drive coupe has been having issues when going up hill at low rpm’s under acceleration. I have been experiencing a clank/backfire like noise that seems to come from the front of the car. The noise can occurs a few times or multiple times and can very depending on how steep the hill is and how much gas I give the car. You may hear 1-2 clanks when on a flat road and hitting the gas, but on a hill it could be as much as 10 during acceleration until I hit around 35 mph. This seems to mainly occur in the rpm range from 1000-1500 rpm going from a standstill up to 35 mph. The clanks seem to be increasing in number over time and concerns me even though no check engine light has appeared during or after it happens. The engine is a 3.6 L V6 with 118,000 miles on it. This is an every day occurrence at this point and I have even replaced all 6 spark plugs and coils after reading bad plus/coils could be a potential issue.


E1086717-08F9-489C-894B-65A45FDA5E49.jpeg


Video 1 of noise:

Video 2 of noise:
 

Attachments

·
Registered
08 CTS DI
Joined
·
2,301 Posts
Welcome to the forum, nice coupe which is on my "To do" list. I noticed the steering wheel is moving in close proximity to the noise and I did not hear what I would consider a backfire, but instead more of a thump. The closest I could come up with is in the video below beginning at the ~:35 sec mark on an SRX. The noise sounds very close to what I hear in your video (which is very helpful). The link to the attitude of the car and speed makes it feasible also, because both will have a pronounced effect on suspension loads. It should be a fairly easy area to check during a suspension inspection.

 

·
Registered
Go ahead, blame me. Everybody does 🙄
Joined
·
9,493 Posts
Seems like Joseph may have pinpointed the source; nice sleuthing.
You noted in your opening post that it's occurring while climbing grade, but the noise in the videos do seem to line up with steering wheel movements.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #4
Welcome to the forum, nice coupe which is on my "To do" list. I noticed the steering wheel is moving in close proximity to the noise and I did not hear what I would consider a backfire, but instead more of a thump. The closest I could come up with is in the video below beginning at the ~:35 sec mark on an SRX. The noise sounds very close to what I hear in your video (which is very helpful). The link to the attitude of the car and speed makes it feasible also, because both will have a pronounced effect on suspension loads. It should be a fairly easy area to check during a suspension inspection.

Thank you for your response and welcome. I know that in the videos I am turning, but after driving home from work I attempted to duplicate the effect on a hill that was straight and still had the clank noise occur. I also noticed that a few times it made a metallic ping almost and the car seems to jolt even though there is no rpm drop as the clank is occurring. I would also like to add that in December of 2019 the engine overheated due to coolant running out. I was able to quickly pull over and called a friend to get some coolant, but it could have caused some damage to the engine or transmission. I am turning in the videos because I happened to be stopped at a light and needed to turn both times.
 

·
Registered
'12 CTS Performance Sports Wagon AWD
Joined
·
2,878 Posts
So here are my thoughts... It looks like you are changing speeds or shifting at the time of the clunks...
You have an AWD car...
The rear driveshaft has a center bearing that goes out...
The times a driveshaft would have load on it would be during heavy acceleration and during an uphill climb at slower speeds.

With older CTS-4's when that bearing would start to wear out the bolts holding it to the transfer case would loosen and shear off. When this happens it can lead to transfer case and transmission failure...
I haven't heard of that happening with a 2012 but it is a great place to look to insure you don't have any major issues down the road.

The biggest issue is replacing that bearing... Apparently it is not easy but if you check threads on here there is a part number for that bearing..
If you take it to a dealer ship or most mechanics they want to sell you a new $700 axle and the labor to disconnect your exhaust to get at it. (The labor would be the same but instead of a $700 driveshaft I think the bearing was like $20 so the labor to change the bearing... Or if you can do it yourself...)

So you have two things to check while the car is on a hoist... You probably have to put the car in neutral to check for play in the drive shaft. Then you can also check for play in the sway bar bushings too.
Not sure grabbing a used one would even be a good idea if that is it..

You might check the center bearing much like you would a U-joint... Change directions and listen for a clunk... Accelerate hard then let off the gas.. Etc..
 

·
Registered
08 CTS DI
Joined
·
2,301 Posts
His noise location has a front end focus if I understand correctly and the metallic, clanking sound still points in the direction of the sway bar, except now, the ball and socket sway bar links, which are known to sound off when they wear out. A good front end inspection, following a description, or the video demo should help rule them in, or out. I doubt the noise has anything to do with the motor in the absence of an effect symptom. This is one of the downsides to a car that is generally very quiet, you hear every little noise, which makes it a big problem whether it is, or not.

Have it checked out since an overheat was involved. As amazing as it sounds, the reversion into the intake that these motors some times give off on cold starts also sound a little like the noise heard in your video. It's difficult to say for sure, not being there to hear it in real time. If you changed the plugs and coils, I have to suspect sitting in the car gives the impression the noise is from the motor. Check your coolant level, no mention as to how it was lost was made leaving us to wonder. Check your oil level also.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #8
His noise location has a front end focus if I understand correctly and the metallic, clanking sound still points in the direction of the sway bar, except now, the ball and socket sway bar links, which are known to sound off when they wear out. A good front end inspection, following a description, or the video demo should help rule them in, or out. I doubt the noise has anything to do with the motor in the absence of an effect symptom. This is one of the downsides to a car that is generally very quiet, you hear every little noise, which makes it a big problem whether it is, or not.

Have it checked out since an overheat was involved. As amazing as it sounds, the reversion into the intake that these motors some times give off on cold starts also sound a little like the noise heard in your video. It's difficult to say for sure, not being there to hear it in real time. If you changed the plugs and coils, I have to suspect sitting in the car gives the impression the noise is from the motor. Check your coolant level, no mention as to how it was lost was made leaving us to wonder. Check your oil level also.
As far as the coolant level, I would say I’m close to where my level should be. I had the vehicle taken to a local Cadillac dealership after the overheat out of fear of damage to the engine and transmission. I told them what happened when I went in and assume they checked the engine and know they ran codes because the day prior I had my cruise control, while it was engaged, randomly quite with no visual warning on the dash. The cruise control would not re-engage the rest of my drive home (about 20 miles), but worked fine the very next day it was drove. The dealership was also informed of this event, but could not find a leak in my coolant system, but did notice a code in the history for the cruise control failure. I changed our all 6 coils and sparks with OEM parts on 2/22/20 and checked my oil level. I was right at where if there was any less oil I would be in the hash marks on the dip stick indicating low oil. I added 1 quart of oil of the same type I normally buy (Mobil 1 synthetic) to be on the safe side. My oil quality indicator is at 15% and the oil looked fairly dark when I checked it. I do plan to have an oil change within the next week.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #9
UPDATE
Recently I was driving on the parkway with cruise control on and all of a sudden my ABS, traction control and traction control off lights came on. The vehicle is now saying Service Traction Control, Service Break Assist and Service Stabilitrak. This could be a separate new problem, but wanted to include this in case it provides a clue. My vehicle when taken to the local Advanced Auto Parts showed 3 codes, one was the cruise control sensor and the second I don’t recall being serious. The new code that stood out was C0045 Left rear wheel speed sensor circuit - erratic.
578584

578585

578586

578587
 

·
Registered
08 CTS DI
Joined
·
2,301 Posts
"The devil is in the detail", still haven't figured out exactly what the meaning of that phrase is intended to be, but it sounds appropriate. My first thought to the cruise control failure would be that it was possibly shut down due to the coolant temp, if it is working correctly now, or the intermittent spontaneous inop status that many including myself have experienced. Some point to the brake pedal sensor (no longer a switch) as the cause and others, poor contact at plug connections, usually the BCM. Since I unplugged and plugged in all of the BCM plugs two years ago, it has not happened since.

I would be more concerned about the low oil level, or nearly low oil level. A low level can potentially become a very low level during spirited throttle input as the oil gets pumped to the top of the motor faster while draining back down at the same rate. I wouldn't wait that long to change it either, usually by 50%, or 5000 miles as I've also discovered the 3.6L is hard on motor oil.

You posted while I was typing this. That wheel speed sensor code is the likely culprit for the stabilitrak and associated warnings.

Did the dealer fix anything, or offer any useful ideas as to what was going on?
 

·
Registered
Joined
·
5 Posts
Discussion Starter #11
UPDATE 2
I ended up taking the CTS to a local mechanic in town yesterday, after having two mechanics drive the vehicle they told me “the click/low pop noise seems to be coming from the front and is priority. The abs light and traction control are due to the bearing wearing out on the rear drivers side. They recommended I should see a transmission specialist or go to the dealership because they recently had their transmission guy retire.” They recommended a local transmission specialist. I left the car with him overnight and he told me today after driving the car and looking at it that he did not believe the noise was a transmission issue, but couldn’t be sure. I have scheduled an appointment with a local Cadillac dealer, but worry with the car being out of warranty and not sure if they will provide a true 100% solution to my problem. The local mechanic I took the car too did find a few more codes with the complete list below. Thank you all for your help and advice.

CODES:
P0564 - Cruise control multi function
CO045 - Left rear wheel speed sensor
CO899 - Device #1 voltage below threshold
B2555 - Pass side compartment lamp short (possibly from cheap LED aftermarket interior bulbs I installed that flicker when they are on)
B1850 - D side
 

·
Registered
Go ahead, blame me. Everybody does 🙄
Joined
·
9,493 Posts
Replace the left rear wheel bearing first.
Clear codes and see if anything else returns.
 

·
Registered
2013 Black Diamond CTS4 Premium Coupe (sold-09 CTS4 DI Black Raven/Ebony)
Joined
·
4,365 Posts
Agreed. You know the wheel bearing needs replaced. Do it first to eliminate it causing any other symptoms. Then look at the clunk. I'm sure they looked, but could the center driveshaft bolts be a bit loose. Not enough to see them backing out yet, but loose enough to allow the driveshaft to make noise? Check the bushings Joseph pointed out. Then back to road testing to see what is still making noise.
 

·
Registered
2009 CTS4 Premium & 2012 SRX4 Luxury
Joined
·
686 Posts
I'm sure they looked, but could the center driveshaft bolts be a bit loose. Not enough to see them backing out yet, but loose enough to allow the driveshaft to make noise?
When I saw the title of this thread, CTS4 low speed clicking, that's what I immediately thought of, driveshaft to transfer case bolts backing out. But then I watched the videos and it didn't sound the same as when mine had that problem.
 
1 - 14 of 14 Posts
Top