Many owners of General Motors’ 2015 and 2016 full-size SUVs are not particularly happy with their purchase.
Online forums and the National Highway Traffic Safety Administration’s (NHTSA) complaints database are flooded with posts alleging that GM’s full-size SUVs, including the Chevy Tahoe and Suburban, GMC Yukon and Cadillac Escalade, all exhibit the same off-putting traits: unexplainable wind buffeting and vibration. Many of the complaints allege that these problems also affect the Chevy Silverado and GMC Sierra.
AutoGuide.com was first made aware of the issue when Daryl Watkins, the owner of a 2016 GMC Yukon XL Denali, alerted us by e-mail. “I am the new owner of a 2016 GMC Yukon XL Denali,” Watkins said. “Imagine the sound/feel when a window is cracked riding down the road except it occurring when all windows are up and at all speeds above 35mph.”
Along with the buffeting, a vibration can be felt inside the cabin. According to many of those affected, the sensation gets worse when the vehicle switches into V4 mode, as these engines are equipped with cylinder deactivation.
And it’s not just an annoying sound – the defect seems to be causing some health issues.
“Pressure, sound and sensation at low to mid range speeds. Creating headache, dizziness and strain,” reads one complaint on the NHTSA database ( NHTSA ID Number: 10701714).
More complaints can be found online, including on forums, though there are some posts from owners who have have a GM SUV and have no buffeting or vibration. AutoGuide.com‘s editors have put plenty of miles in numerous examples of these big GM trucks, from the Cadillac Escalade to the Chevy Tahoe, and have never experienced anything like what Watkins described.
Still, the overwhelming outcry on the Internet over the problem is too big to ignore.
The (Supposed) Fix
GM issued a preliminary information bulletin (PIT) over the issue. Poorly attached roof sheet metal is the main issue that GM looked to fix and instructions for doing so are located in PIT5318B. To perform the fix, technicians have to remove the vehicle’s headliner and inspect the roof bows for proper bonding with the roof sheet metal. If there is an issue, the bonding must be completely redone, which means new panel control vibration material is packed into the roof of all SUVs that have received this fix.
The problem with this PIT, as many customers have learned, is there is no guarantee it is going to help. The PIT reads:
In some cases, correcting the roof bows may not eliminate the body pressure booming issue due to the fact that the roof is being excited by some other input(s). These other areas will need to be addressed if the body pressure booming is still present at the completion of this PI.
Those other areas include tire issues, exhaust back pressure valve issue and rear axle issues.
With no clear fix for this problem, customer frustration is building, especially since the response from dealers has been varied.
“Vehicle has a vibration when going between 60 – 70 miles per hour on the highway,” reads a NHTSA complaint about a 2015 GMC Yukon (NHTSA ID Number: 10787343). “Took vehicle to dealer, they said the issue was caused by recall that GMC was trying to fix. Currently no part is available to fix [the] vehicle. Instructed to just keep driving vehicle with the vibration until a part is issued.”
This sentiment is echoed around a few forums, where customers have been told that there is no fix, or that their vehicle is operating normally.
When customers bring their SUVs into their dealer, the repair process seems to be almost always be the same. It starts with road force balancing, because out-of-balance wheels are the most common cause of vibration at speed. Many dealerships have also replaced wheels and tires, but for customers like Daryl Watkins, new wheels did not help.
New drive shafts, replaced exhaust systems, new shocks and even entire rear axle assemblies have all been put into different SUVs across the U.S., and still the majority of owners complain that they were of no help.
“Vehicle has a terrible vibration,” reads another NHTSA complaint about the 2015 GMC Yukon (NHTSA ID Number: 10681579). “Has been to dealer seven times for a total of four weeks. A GM engineer has looked at it twice. They have replaced ring/pinion, driveshaft, axle. Tried it with four sets of tires/wheels. Last idea was to replace shocks, struts, sway bars with hand built parts, cut brackets off car and welded new brackets on.”
All of this did nothing to help the vibration, according to the customer, who claims that a GM engineer told him that the problem is a large one.
“A larger issue was relayed by engineer to service manager at dealership. Issue is with all 2015 Tahoe, Yukon, Escalades. In an effort to prevent rollovers, the frame and body mounts [are] too stiff. There are 40 engineers working on [the] issues, [but] they have no solution across the board. According to [the] engineer, GM is keeping on eye on how many units they have to buy back or trade for. If the number is low enough, they will not make any changes to design.”
In some cases, GM dealerships have approved the use of Dynamat, a special sound damping foam, in the roof, which is installed when performing the PIT. “My dealer reattached all roof bows and added Dynamat which fixed it for a few months,” wrote one customer in a private Facebook group. “After inspecting the roof it appears mid bows are no longer attached to the roof. When the roof is secured the truck is just plain awesome. When it is not, it booms and buffets.”
The Facebook group, created to connect owners struggling with these problems, is full of new-car buying horror stories. “Today is 34 consecutive days in the shop (5 weeks tomorrow). They have now replaced my rear end and called to tell us there is still a vibration,” said one owner.
The NHTSA database also shows a host of similar complaints on brand new GM pickup trucks. “The contact owns a 2015 Chevrolet Silverado equipped with Goodyear Wrangler SRA tires,” reads a NHTSA complaint (NHTSA ID Number: 10807437). “While driving between 65-75 mph, the vehicle started to vibrate. The tires were replaced, but the failure recurred. The approximate vehicle and tire failure mileage was 3,400.” There are also massive forum threads covering the issue with the pickup trucks.
Watkins’ 2016 GMC Yukon XL Denali has had the driveshaft balanced and the tires and wheels switched out two different times, and yet the problems persist, especially the buffeting.
How are Dealers and GM Responding
In one case we found, GM repurchased two SUVs from the same customer after performing the PIT and after multiple other fixes did nothing to help the buffeting.
We reached out the GM to find out what the brand had to say about the problem. “This was an issue that was fixed in production at the end of the 2015 model year. In addition, there is a service bulletin for repair for the field,” said Michelle Malcho with GM communication.
Watkins, who owns a 2016 GMC Yukon that exhibits both vibrations and buffeting, would not agree that the issue was fixed. AutoGuide responded to General Motors, asking what exactly the fix for the SUVs was, but as of publication time, we have had no answer.
Out of four months of ownership, Watkins says that his Yukon has been in the dealerships for a total of 87 days, while he has been relegated to rental cars and dealer loaners for that time. Like many other frustrated customers, he just wants what he was promised: a full-size SUV that’s both comfortable and reliable.
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