I have a 1999 chevy express van 5.7L engine and when I drive only it makes a loud rattling knocking noise any answers???

SOURCE: 04 Endeavor rattling noise

I had the same problem! I crawled underneath the car and discovered that a heat shield on the exhaust header pipe was corroded and rattling against the exhaust pipe. (Before the muffler)
I removed the portion and clamps and solved the problem. Give it a try.

SOURCE: 1999 Chevy Express Van Side Door will not open

You need to replace the handle itself. The inside of the handle where the metal cable fitting attaches causes too much strain on the plastic and the molded groove breaks. Ford has the same problem. I don't know why these car man. dont just go back to all metal exterior handles. If you have time you can probably fix it with epoxy and washers, but the fastest way is to get one aftermarket or from a junkyard. Hope this answers your question.
Please remember to rate this fix.

SOURCE: Rattleing noise between 2500-3500 rpms 01 protege

Just took my car to the shop for the same appearent reason me also thinking it may be lifters. My mechanic said it spounds like a worn wrist pin ...... bad news for you if this is the case .......recomendations rebuild the engine or buy a new or remanufactured one. if the wrist pin lets go then you could throw a rod. If you must drive the car please be gentle

SOURCE: engine or transmission knock / rattle upon

I had the same problem on my 2006 Lucerne and it was the engine mount located on the front of the vehicle behind the radiator.

SOURCE: 2000 chevy express 1500 van having starting issues

Start with fuel system. Listen for fuel pump humm at fuel tank No humm check wiring to pump for power. Then check for spark at plugs and wires. Remove wire from coil and hold near engine and see arch when you crank. No arch. Replace ignition Modular inside distributor cap or cap or rotor