Truck will work relatively normal when cold, as soon as engine heats up acceleration gets sluggish and very busy especially when going uphill. Been told about it being in "limp in"mode and something to do with transmission maintenance. Would like more specific model/year details to go fix. There is also a loud roaring sound when accelerating and it gets quite hesitant when switching to Reverse (R). Thank you.
My car has 114000 miles.
My car has an automatic transmission.
Hey there. If your truck is in limp in mode, the PCM (powertrain control module) believes there is something wrong and it is attempting to protect itself. The place to start is connecting a scanner to your truck to read any codes and study the scan data. Only with this information can we point you in the correct direction. By following a diagnostic process that begins with a scanner, we can discover clues as to what is wrong.
As for the roaring sound when accelerating, this is most likely your fan clutch locking up. When the hydraulic fan clutch locks up, the fan will pull lots of air through the radiator and create a very loud rushing noise. This is normal, with one exception. If the fan clutch is frozen, it will be permanently locked up and this will creating a non-stop rushing noise heard at all times. If the noise goes away once you reach speed, then it is working correctly. If the noise is always there (cold and warm), then you should have the fan clutch replaced. A qualified professional from YourMechanic can come to your car’s location to diagnose the vehicle’s loss of power if you are still having trouble.
Have a car question? Get free advice from our top-rated mechanics.