Sounds like it is time for a complete tune-up.
Fuel Pump
its getting ready to explode. jump out quick
Dude, the engine is smoked. Sorry to have to tell you.
Gravity.
Is your oil level?
Common causes of lower back pain when walking uphill include muscle strain or fatigue, poor posture, improper footwear, and underlying conditions such as herniated discs or spinal stenosis.
because it is going uphill and the engine has to work harder?
Bad spark plugs are plug wires.
Once you have achieved highway speed, you would stay in the highest gear, except for steep uphill or downhill grades.
HONKING means to "ride out of the saddle" or standing. Honking is often used when accelerating or riding uphill. HONKING is also a trademarked term for a new form of indoor cycling group class.
Is the vehicles transmission downshifting to a lower gear as you go uphill? If not, that would be your first place to look. After that I would suspect that your engine timing is not autmatically advancing as it should be.
The amount of load it is hauling, whether inside or like pulling a trailer. Also using the air conditioning while going up very long grades on the roadway will cause overheating as the engine has to work harder going uphill and adding the drag of the air conditioning pump only makes that more difficult.