Gas leak. My 2018 gmc sierra 1500 has been giving me two codes for evap leak small and large and i notice a black spot on my drive way under the gas tank wich in fact was gas. I can see the gas tank is wet but it comes from the top part of the gas tank. I been looking for recalls on this but there isnt any for this specific year of GMC sierra 1500 slt.

- Brooksville , FL, USA

The speed of the truck will not increase. The rpms goes really high and the truck will not move into the next gear. The rear end of truck vibrates. I took this to the dealer and was told it is the transmission fluid is faulty. The check engine light does come on. I did not have the new transmission fluid changed because dealer said is cost $300 for the fluid and $100 for the labor and $168 for the diagnostics. So I still have the same problem. Also told you can not purchase this transmission fluid no where but GMC.

- Tickfaw, LA, USA

I was driving down the highway when my vehicle loss control of operation and check engine light came on. After taking it to the GMC dealership it was determined to be a bad lifter in the motor. The garage had to take the motor completely apart to repair a bent rod and cylinder in the motor. There are numerous reports and a pending class action lawsuit concerning this device in the GMC Sierra trucks and other GMC vehicles. The lifters in the cylinder of this motor are designed to switch the engine from V4 to V6 to save on gasoline. My vehicle has been repaired by the GMC garage but I've seen reports of this problem repeatedly happening in these vehicles and it causes me great concern because if there is a lot of traffic in the area I could get hit or cause an accident by not being able to operate the truck. My vehicle is available for inspection upon request. The safety of myself and others is put at risk because the sudden equipment breakdown could cause an accident. The problem was confirmed by the dealer. No other parties have inspected the vehicle. No warning lamps went off prior to this happening and the vehicle is only a 2018 and only has 36,000 miles on it.

- Albright, WV, USA

After long periods of running and idle, vehicle stalls out has a hard time restarting. Gas paddle being press helps sometimes. Check code P2635 plus others (random secondary codes), come on. This has taken place in AZ where the ambient air temperature typically is over 100. Vehicle has been to GM dealer who says its vaporizing the fuel in the lines. Tsb pip5507B dose not include 2018, however the design hasn't changed. Conditions; long idle, hot weather, low speeds under 25 mph or idle. Location; AZ sonrona dessert, off-road, jobsite, city streets.

- Phx, AZ, USA

When 1st cranking truck and put in drive motors rrev up and shifts hard to second. Occasionally when I out in reverse it will sit there N not shift in. Then when it does it shifts hard. When accelerating the truck it sounds like a clattering sound under drivers side under hood. Tried different type of gasoline and nothing changes. Gmac needs to do a recall on both of these items. I am very disappointed in my GMC and gmac

- Bullard, TX, USA

The Sierra surges from park to reverse and drive. I bumped a vehicle today, and the surge has become an issue this week and there is not even 9,000 miles on the truck. The afm is rough shifting between V8 and V4 mode too. None of this was an issue until recently. My speakers also vibrate like a blown speaker on high definition radio, but not on regular radio stations.

- South Bend, IN, USA

Fuel injection seals #4 O-ring split - leaking fuel - pooling gas on manifold. Took vehicle in for smell of gas, lack of acceleration and poor gas mileage. This is known issue based on the service bulletin 18-na-137 - vehicle has less than 6000 miles

- Inver Grove Heights, MN, USA