Driving back home from lunch and my Terrain was knocking and wobbling really bad. So I pulled over to the safest area I could find and shut the car off. GMC towed it that same day & said had I ran it any further, it would have blown the motor completely. They replaced all of the seals on it. 2015 they replaced the water pump, 2016 they replaced the TPM. One thing after another with this car. Dealer just charged us $7K to replace an engine in our other car H3, so I cannot afford to take it in again. It seems as though GMC is giving all of their customers the shaft and refuse to listen to their customers. I used to trust GMC, now I'm not so sure anymore.

Have a 2012 GMC Terrain. At 79,000 miles (6-28-2017) the vehicle leaked around the timing cover gasket and crank seal. Extended warranty expired in March 2017. Vehicle gave no indication that it was low on oil. Only heard a grinding noise from the motor and checked oil, finding that it was not registering on the stick. Had leaks repaired at Midas and new timing belt due to having to open to replace cover. Car ran for six months, we still had to manually monitor vehicle oil level and it still leaked.

On Dec. 27, the vehicle stopped on the highway with a reduce speed warning. Had it towed to dealer (ANDY MOHR GMC BUICK). They said the rear main seal was out of the vehicle. They replaced the rear main at ($1500) and said that the top end of engine was also damaged estimated at $1900. They suspected blocked PCV valves caused the rear main seal issue. This seems like poor engineering issues for this motor. No low oil indication, no engine breathing if PCV valves fail. Looks like the logical fix is to replace the engine.

I have 2012 GMC Terrain on 12/12/16 oil started leaking after extending driving in cold, car would not start. Took car into Mechanic and apparently rear main seal had blew out causing major oil leak. Mechanic went to GMC dealer and received document from GMC saying that Oil leak from rear of engine after extending driving in COLD temperatures below 0 F (-18C) (Jan 22, 2016 ) I Live in Indiana where temperatures go below 0 F. Document states some customers may complain of engine oil leak that appeared as they were driving the vehicle in extremely cold ambient temperatures (Generally 0 F/-17 C or colder) Upon inspection the technician will find that the oil leak is coming from the rear main oil seal of the engine. This may be the result of a frozen PCV system and excessive crankcase pressure.

Well to make long story short we need new engine cause all oil leaked out without any warning lights coming on.