2014 Traverse 3.6L Terrible Noise and Vibration

2014 Traverse LS 3.6L V6 My problem started in June 2021 when my A/C Compressor burned up and contaminated my entire A/C System. I took it in to my local Shop for repairs. The Compressor was replaced along with the Front and Rear Expansion Valves, Front Condenser, and the High Side Line of the A/C system. After a good flushing, and vacuum and Freon re-charge, all was good and back on the road again until March of 2022.

I started the Truck one cool morning in March, and after shifting into Reverse, I heard a terrible, very loud vibration noise under the hood. I should note the A/C system was not turned on at this point. The Noise seemed to get a lot quieter and/or disappear completely when in Park, or when I shifted into Drive and accelerated, or as the Truck warmed up. I returned the Truck to the same local Garage for diagnosis. A few hours later, they called and said my Motor Mounts were bad and needed replacement. Since my Truck had 105k miles, and I live in Arizona where Rubber just doesn’t hold up in the Heat, I guess I wasn’t really surprised and gave them the Go-Ahead. After paying $700, I picked up the Truck and drove it home.

The Next Morning, when it was cool, I started the Truck and the Noise returned with no change, still loud and still vibrating. I called the shop and scheduled another appointment. They were flabbergasted that the noise was still there. On the second trip to the Garage, I was told that the problem was the A/C High Pressure line that was vibrating and rubbing against the Fan Shroud, causing the noise and vibration. They told me you could see that the Line was vibrating and if you grabbed the line with your hand, the vibration stopped, only to re-start when you let go. The garage removed the High Pressure Line that they had installed previously in June, saying they suspected it was an inferior Aftermarket Line and was possibly bad. They replaced it with an OEM High Pressure line from a Local Dealership at no charge. I picked up the Truck and was told all was good.

The next Morning, the noise and vibration was back again. I lived with this situation for a couple of weeks at the request of the Garage to see if anything else developed. I asked them why the A/C Line was vibrating and making noise even with the A/C turned OFF. Their answer was that the A/C system was still under pressure and would still vibrate. Then one afternoon, the A/C stopped working completely. I took it back for the Third time and they found the Brand New OEM High Pressure Line had snapped off at the Compressor Fitting due to the vibration, and all the Freon was lost. They replaced the broken line with another OEM Line at no charge. The next morning, the noise was still there. I called the Shop again and they were completely baffled and frustrated.

At this point, I decided to go to a Dealership, thinking that perhaps one of their mechanics had seen a similar issue. The Dealership told me that the High Pressure Line was vibrating against the Fan Shroud, and they “Adjusted” the line away from the Shroud, and “Secured it”, and the noise was gone. $85 Dollars later (1/2 hour of Labor) I drove home. The next morning, the noise was back, only now it was audible with the A/C on or off, in forward and Reverse and as loud as ever. I was afraid to drive the Truck at this point for fear of breaking another Line.

I called the Dealership again for the second time, (and the 5th trip to the Garage total). The Dealership took the truck in and later that day I got a call that the Truck was ready to pick up and there was no charge. When I arrived at the Dealership, I asked what they did or found to repair the problem. I was told that there is a large Bracket that is mounted to the Engine Block where both the A/C Compressor and the Alternator are mounted. The Bolts holding the Large Bracket to the Engine Block were all loose, and all they did was re-torque them to Factory Specifications. A month later, I am happy to report that everything is still quiet, Thank God! That explains why the A/C Line would Vibrate whether the A/C System was on or off.

I did call the original Garage and told them what was found. Their response was, “Wow, nobody checks those Bolts, there is no need to, as they never touch them”.

I wouldn't normally waste your time or mine with such a long thread for such a trivial issue, but after 5 trips to the Shop, and playing "Stump the Band" with a number of Professional Mechanics, spending a lot of Money, (not to mention the frustration and anxiety), I just felt obligated to pass this information on in hopes this might help Professional Mechanics or Owners that run into the same problem. So if you hear a loud noise in reverse, A/C on or off, that goes away when you accelerate in Drive. Check your A/C Compressor / Alternator Bracket mounting Bolts and save yourself a lot of Frustration and Money! Huge Problem, Simple Fix. Rick

Good info, if it was looked at more carefully most likely this would have been found earlier, odd issue though.

Good info, if it was looked at more carefully most likely this would have been found earlier, odd issue though.

Thanks MaxWedge, I agree completely!

If you Google Vibration Problems on this, (or just about any engine) Bad Motor Mounts are almost always in the top 5 reasons. Vibration Problems and "Funny Noises" can be extremely difficult to diagnose and are a Mechanic's worst Nightmare.

I don't dispute that my Motor Mounts were bad as the Shop that I go to is genuinely Honest. My 8 Year old Truck had 105K Miles in the Arizona Heat, and Original OEM Motor Mounts, so I'm sure the Mounts were ready to be replaced, even though they were not the cause of this problem.

I'm sure there are "Quick Judgments and Standard Diagnosis's" in many shops, meaning "Standard or common Complaints" will lead you to "Standard known Textbook Fixes", which MAY correct your problem, but maybe not. The age old "Don't just start throwing parts at it rule" comes into play here. Good and Thorough Diagnosis is crucial.

I once had a power steering pump bracket fatigue, fail, and cause more catastrophic damage due to a brace not being replaced by a dealer service department after previous repairs. The devil is in the details.