Manic Mechanic is episode 6a of season 3 of the Rocko's Modern Life.
Rocko's car breaks down on the way to a big concert. They try to get it fixed by professionals but they simply laugh at the car. So they take it upon themselves to get it fixed.
Rocko and Heffer have received front-row tickets to a classic show and are about to drive there in Rocko's car. At first, the engine chokes a bit as Rocko attempts to start his car, but it finally activates and Rocko and Heffer ride through the road. But the car's engine shuts off again as the car approaches a stop sign. Since Heffer has pulled his hamstring, Rocko has to push the car uphill. But the car begins to slip and starts falling downhill. Rocko tells Heffer to put on the brakes. But the car crashes down the hill since Heffer has misconstrued Rocko's words and thought he said "steaks." Rocko forgives Heffer's mistake and becomes worried that his car is sputtering. While Rocko contemplates taking it to the shop tomorrow, his car's spirit floats up in the sky and comes across the grim tow truck, who leads it to the big garage in the sky.
The next morning, Rocko and Heffer haul Rocko's car to the car shop to get it fixed. But the mechanic mocks the car, saying that it is a tricycle with an extra wheel. He also says that he and the others are participating in the O-Town Rally on Sunday and says that Rocko is better off selling his car for scrap. Rocko becomes angered and says that not only is he going to fix his car himself, but his car is also going to prevail in the O-Town Rally. Heffer hops inside the car and Rocko pushes it home.
Back at Rocko's house, Rocko and Heffer prepare to fix the car with a tool box and a repair manual. When they find that there are a meager amount of tools inside the box, Rocko decides that he and Heffer would just improvise, having himself work while Heffer reads. Rocko attempts to remove the outer housing plate screws, but ends up getting sprayed with oil, forgetting to heed Heffer's warning of first turning the bolts a half of turn clockwise. As Rocko starts working under the car, Spunky ends up eating most of the tools. Rocko then decides to acknowledge the fact that getting his car fixed is futile, until Filburt comes around on his moped and takes a look at Rocko's car, stating that he is an official graduate of mechanical school. He says that he will bring the car back to life and while repeating dialogue from the film Frankenstein, he has Rocko's car raised through the roof of the garage. But it only ends up being struck by lightning and Filburt ends up trying another tactic.
While fixing the car, Filburt tries to connect the wires to the correct spots. But he fails when he connects the red to negative and black to positive (which is really the other way around) and soon, he finally runs out of ideas. Rocko then tells him that he noticed that there is a switch inside the car that was on "broken" the whole time. So Filburt orders Heffer inside the car and Rocko flips the switch to "fixed," literally bringing Rocko's car back to life. As Heffer celebrates, he accidentally hits the gear shift to reverse and the car rides away in reverse. Filburt tells Rocko that he has forgot to connect the accelerating return springs, the transmission cable, or the brake pads, meaning that in order for the now-running car to stop, it would either crash into something with great impact or the engine will overheat and explode. So while Rocko's car continues to ride through the road, Rocko and Filburt prepare themselves for safety and ride along on Filburt's moped. They come across Heffer riding through the train tracks, with the train following behind. Filburt brings the moped to a stop and Rocko hops off to hit the lever to separate the train tracks so that the car Heffer is in escapes from the train. Rocko's car then falls off the cliff, rides through the Cliffside Amusement Park roller coaster, and ends up participating in the O-Town Rally. Rocko and Filburt catch up and tell Heffer to hop onto the moped to avoid getting into contact to the impending explosion of the car, which Heffer quickly acquiesces to. Rocko's car ends up winning the race (and running out of gas in the process as well) and gets a free tank of gas, which causes it to run into reverse and collide into Filburt's moped, two of which crash into a brick wall together and end up with their spirits floating to the sky. Filburt puts on his silly head dress and says "Boom shwatti oosh" as the episode irises out.