I have noticed lately that my car is a little sluggish. When I accelerate to high RPMs (3+) the car begins to jerk and I can also hear a metallic knock coming from the engine. I'm not quite sure if this is something to be concerned about.

 

yes a knock is a bad thing. it's the sound of running lean and means you could explode the motor, since it's a high RPM issue i would check the entire fuel system first. Pump, filter, lines, injectors. all of it.

 

The car runs really sluggish on acceleration and spurts/jerks a little around 2.5k-3k RPM. It also makes the heavy knock around 3k+ and when I give it lots of gas, the car jerks more.

 

Just had fuel pump replaced, car seems to be running good at times with acceleration, but other times it goes sluggish. The car begins to jerk around 2.5k+ I'm still puzzled. Engine light came on, but I can't get it into the mechanic until next week.

 

New description:

My car recently died and after having it towed to a mechanic shop, I found out that they had to replace the fuel pump. After receiving the car back, I have noticed that my car is a little sluggish at times, especially when the A/C is on.

The car will run really sluggish on acceleration, almost as if there is a major drop in power to the engine. It always spurts/jerks moderately around 2.5k-3k RPM. It also makes the knock around 3k+ and when I give it lots of gas, the car jerks more.

I have also noticed when I shift it into 5th gear (final gear) on the highway, the car won't want to accelerate much over 70mph and the RPM usually hangs around 1.5-2k.

I'm not sure if this is a simple spark plug issue or a clutch problem.

 

Do a serious Seafoam treatment the proper way. One can in gas tank, one can pulled through vacuum line while engine running for a good induction cleaning. Secondly, are your spark plugs new and gaped properly? Fix those two items and use quality gas, then go from there. Always check for vacuum leaks around the EGR, they are brittle lines that crack easy. Good luck-

 

if you find out what the CEL code is it should point you in the right direction instead of just guessing. advance, autozone, napa, all do code reading for free