While driving the vehicle, I experienced strong knocking vibrations and sounds seemingly coming through the floorboard. As I continued driving for about 5 miles trying to get home, the knocking became more pronounced and my steering was affected. I also began noticing an extremely strong odor necessitating lowering windows to breathe. I notified my dealership and took the vehicle in for diagnosis the very next morning without driving it after arriving to my garage. I was told the AWD had completely deteriorated. My concern was that I never received any dashboard notification of the problem, not did my onstar diagnosis indicate a problem. I have been quite disturbed that the vehicle became disabled before I was aware of any problem. I have taken my vehicle in for regular maintenance at my GMC dealership and would like an explanation regarding the failure to identify this problem through the regular maintenance checks. I am single senior woman who has no backup vehicle and am quite concerned about my safety on the highway and this issue has caused me to have serious safety concerns. I drove the car to the dealership to check on the problem on Friday, February 16, 2018. I called the GMC complaint center to check on possible recalls or any remaining warranties that might apply and I was told the center was assigning a sr. Advisor to contact the local GMC dealership that still has my car and the advisor was told the dealership needed more time to diagnose and assess the cause of the problem.I have had to rent a vehicle since it may be another 2-3 days before I even get a response regarding the nature and cost of the repairs. I was originally told the entire AWD system had to be replaced at a cost of $1500--$2000. I questioned the reason for the extreme malfunction without any warning notices appearing...main reason for my complaint and concern.

- Russellville, AR, USA

PCV system froze...air cleaner has water in it// rear main seal pushed out due to excessive crankcase pressure. #14882 special coverage adjustment covers exact issue however my VIN is not included. Requesting my VIN be added to #14882 special adjustment as it applies to my exact make/model/year and issue.

- Langhorne, PA, USA

On Jan 1st it was 3F out my wife wormed up her Terrain we drove it approximately 12 miles when we started to smell something burning. Next came the engine knocking really bad. We stopped the Terrain and had it towed to the dealership found out the rear main seal blew with such force that the oil covered the muffler. This happened from the PCV being plugged and/or frozen from the cold weather. I recently found a service bulletin for that year make and model that indicates that will happen and there is a special coverage for that.(14882: Special coverage adjustment) I also received a letter from GMC about high oil consumption warranty. The Terrain may exhibit engine oil consumption. That is also a part of that 14882:adjustment now to the point I was told that this issue my wife's Terrain would be covered under the 100K/5year power train warranty our Terrain only has 71K miles on it. But the 5year are up. So GM is not taking responsibility for this issue according to both special coverage the 14882: They adjusted to 10 years or 120K miles but they are claiming even though its for that year make and model and engine and that everything that's listed is what happened to our GMC its not for our Terrain. I told them I also had a letter that they sent to us stating the oil consumption that has a adjustment of 7years 6months/120K warranty witch was part of that 14882: Special coverage they still will not take responsibility for fixing. I believe we are getting taken advantage of in this situation. They are making us pay for all repairs it may need a new engine in result of the rear seal blowing because it lost all the oil. But we would not know till the repairs start or after all repairs are made and the engine seizes. I also was told from the dealer that if we fix it and drive it down the road there is no guaranty that it will not happen again.

- Catasauqua, PA, USA

Vehicle was started after sitting in a parking lot for 8 hours while I was at work. Season was winter. Vehicle noted to be running rough, barely driveable, check engine light on.

- Durand, WI, USA

Timing belt stretched and jumped. Cylinder head broken. Timing belt jumped while driving, began making a very loud rattling noise.

- Nottingham, MD, USA

Timing chain jumping off of sprockets and eating away at the chain guides and tensioners.

- Cabot, AR, USA

The contact owns a 2012 GMC Terrain. The contact stated that while driving at various speeds, the vehicle suddenly lost acceleration power. The contact also stated that while at a stop the engine stalled. The failure occurred on two different occasions. The vehicle was towed to the dealer both the times where it was diagnosed that the entire engine and the transmission needed to be replaced. The contact stated that only the engine was replaced. The manufacturer was made aware of the failure. The failure mileage was 106,122.

- Canyon, CA, USA

Oil consumption issue: I realized about 3 months ago that my car engine would shake a bit on start up and during idle. I took it into the dealership for a diagnostic test and was told that there was very little oil in the car and that it was burnt. I was very surprised because I have never had an issue like this before. So we got an oil change and that was that. Engine still shook on idle and during startup. 5000 miles later I realize that it is time for an oil change and check the dip stick and find that nothing appears on it, indicating that it is short at least 1.25 quarts. I fill it up with 0.5 quarts and still nothing on the dip stick. I have looked online and seen that many others have had this issue of oil consumption with 2010-2013 Terrains and that there is a bulletin on it (below): GM.oemdtc.com/1893/excessive-oil-consumption-2010-2013-Buick-Chevrolet-GMC#comment-1224 I call the dealership and the GMC customer service line, check my VIN and they say there are no recalls on my car. What am I to do? this is an ongoing issue that many others have complained about in bulletins and on the website above. I feel that this issue has done its damage on the engine and is going to cost me thousands to repair.

- Midlothian, VA, USA

The contact owns a 2012 GMC Terrain. While driving various speeds, the vehicle stalled without warning. The vehicle was brought to the dealer for diagnostic testing, but the details could not be provided. The vehicle was repaired; however, the failure recurred. While driving at various speeds, the vehicle began to jerk and hesitate and a loud abnormal knocking noise was heard. The vehicle was taken to the dealer where it was diagnosed that the vehicle was in working condition. The contact stated that the engine failed shortly after, making the vehicle inoperable. The manufacturer was made aware of the failures. The failure mileage was 135,000.

- Walls, MS, USA

The vehicle has been in the shop for 10 to 12 times due to failure with the engine misfiring as well as traction control lights and stability trac as well as transmission not shifting right and loss of power while driving on major highways and brought into the dealership where they tell me they can find or make the problem reappear. But have shown the dealership service department video and have had 3 general motor techs that they hired from hp and been told the vehicle is safe and that there will be no more problems but have been in the vehicle while the problems have happened and have it on video to the point where I almost lost my life yesterday night. The vehicle is a death trap and many customers including myself on GMC Terrain forum as well as online have had the same problem and have been told the same thing that it is nothing to worry about but it is. Please help have been told by GM to keep my mouth shut they would offer me 5,000 dollars for my troubles and that my kids are worth that much from a legal advisor at General Motors legal. Have ask to be taking out of the vehicle for something safe and still I'm being told no......please help

- Easton , PA, USA

Vehicle's transmission slips and does not respond to an acceleration after a rapid deceleration of at least 40 mph. The vehicle will jerk in response to your attempt to accelerate and then will respond. This can lead to a dangerous situation if you are attempting to avoid a collision by accelerating to get out of the way.

- Saint Charles, MO, USA