"Front bank: 1-2-3. Rear bank: 4-5-6. Firing order is 1-2-3-4-5-6. Wait—no, that's wrong." He squinted. "1-2-3-4-5-6? Hell no. It's 1-6-5-4-3-2. That’s right. GM’s oddball. Makes it sound like a tractor with a cold."
I can’t generate an actual diagram image, but I can tell you a story that walks you through one—as if a grizzled mechanic named Frank were tracing it with his grease-stained finger on a torn page of a 2004 service manual. Frank pulled the faded diagram out from under a pile of oil filters. "Chevy 3.1L V6," he muttered. "The little engine that wouldn't die—until the intake gaskets did." Chevy 3 1 Liter V6 Engine Diagram
He tossed the manual back on the pile. "Now go draw that diagram yourself. It'll teach you more than any picture." "Front bank: 1-2-3
He circled a lump in the diagram. "See that? The distributor. But by late '90s, it's got a cam position sensor underneath. No rotor. Kids today don't know the joy of setting timing by ear." Wait—no, that's wrong
He slid his finger up a set of vertical lines: .
"Sequential fuel injection, not batch-fire. So the diagram shows six little squares—those are the injectors, one per cylinder. The fuel rail runs right across the top like a silver spine. And that round thing on the front? EGR valve. Clogs up constantly."
Frank folded the diagram. "Moral of the story? The 3.1L was a solid mule—great torque for minivans and Luminas—but it had two fatal flaws: intake gaskets and a timing chain tensioner that whispered lies before failing. If you see one running with clean oil and no coolant loss, shake the owner's hand. They survived the war."