ok, so i had gone to get some pizza today from a local joint, and left the RS running (it was running just fine). when i got back out to the car
i could hear a rythmic knocking that sounded like it was coming from the top end of the engine. i got home, shut it off and came back out to it about 4 hours later and fired the car back up. at first it sounded fine, until i gave it some gas. then the knocking started to gradually come back. any ideas on what it is???

1990 Camaro RS
3.1L MPFI v6, bone stock
173,000 miles on the odometer
looking for boost

 

Knocking from top of the engine is not very common unless something broke. Are you sure it is coming from there, or is it more like a ticking/clacking noise rather than a knock?

 

It may sound like its coming from the top end (sound is lighter than air so it travels up ) but a dull knocking may be your lower end taking a ****e.

 

i can guarantee it's coming from up top. it's MUCH louder up top than under the car

 

Put a piece of heater hose to your ear and move the other end around the engine to locate where the noise is exactly coming from. The hose will act like a stethescope. Or if you have a stethescope use that. Finding the exact location might help you to determine what the problem is.

 

How much oil is in the engine? Is the oil pressure good?

 

i have no clue on my oil pressure (guages have pretty much taken a dump), but i just changed to oil last week.

 

Find a way to check oil pressure, My father went through this on his '89 Suburban. Oil pressure was non-existant and the motor was knocking like MAD, the lifters were all dying, once he got the oil back up to the top of the engine it stopped and runs fine. Aside from who knows what may have happened when it was being run anyway.

 

I would say it would be the lifters if it is a ticking noise, never really new it was probably due to being 1/2 a quart low, but every chevy I have rode in most likelly burned oil at one time or another and always made a ticking noise, lumina, camaro, blazer. When you press the gas the tickingwould gofaster. Put more oil in but not toomuch or the lifters could be all gunked up with sluge.

 

i was wrong...[&o]

pulled the bottom end apart, found the oil pump had literally eaten itself alive[&:] 3 main bearings spun[:@] i'm done with the 3.1, time to find a trans for the 350, and get that into the RS