Tapping noise near computer 1994 Chevy 1500 Silverado

Have to remove the front timing cover
& replace the gears & chain set on a V6

On a 4 cyl you may only have to do the chain &
tensioners

Need a manual for torque specs & anything you
don't understand

do you have a thermostat in

Try starting the truck so it makes the noise.
Then switch the air control to "fresh".
If noise stops, it is probably the motor that closes flap to recycle the cab air.
It would be found under the dash, under the glove box, & would need to be replaced.

it means your transfer case is not engaging or front diff not engaging.should here a shifting noise under the floor .if not the shift motor is not working try tapping the motor and see if it works.poss water has rusted the connections or the motor seized.

It could be lifters but its more likely that your not getting oil to the top right away. Probably plugged oil passages in the cylinder head. Remove the valve covers and clean it out. Change your oil and see if it helps. The damage may alreay be done though

As with all vehicles it seems the first part that they build around is the heater core. It is under the dash above the floor housed in a black plastic sealed box. Sealed with goop. Locate that box and start removing everything around it that is peventing taking the cover off. Of course disconnect the heater hoses under the hood a thefirewall.

Warning it is never as easy as it sounds.

turn the key to accessory , towards drive. Use a paper clip to press in in key face hole and remove the tumblers. the see if you can push the key out from the othe or by tapping it on a firm surface. Good luc

The coil, one is a constant 12v source, the other is a remote ignition source.

Hi!
From your Brief description it appears you have a lazy lifter, A good engine oil flush with a Quality ~Synthetic oil replacement plus filter should help also try a fuel additive you may be using poor quality fuel?
Press the Blue Button please to appraise my FREE! Effort.
Thank You!
Paul 'W' U.K.

your speed switch located in heater box usually one wire to it in passenger feet area above "TOES" usually you loose 1 or 2 speeds on fan but it is unplugged or completely cooked good luck!