Hello all,

I have had this problem now for about a month, first off the car is a 1994 z28 all stock, i keep getting knocking from the engine when I'm driving down the road and i push on the gas just slightly, almost sounds like bad gas but I'm only using 93 octane. the other day i took to get emissions done to it and had to hold the rpm's at 2500 for 20 sec's, well after that it was knocking real bad for about 10 sec's when leaving, i have put a new opti, plugs, and wires, any thing else i might look at to get this problem fixed?

 

What grade/viscosity oil are you using? Have you checked the oil to make sure it isn't being diluted by fuel? What is the oil pressure at idle? ..... at 2,000rpm?

 

well i just had oil changed 4days ago an d had 5w30 put in. and the oil presseure is in between 60 and 80 psi at 2000 rpms.

 

Did the knocking happen after the oil change cause my sister had the same type of problem and it turned out that the oil shop ran it with out oil and snapped a connecting rod

 

nothing beats a mechanics stethoscope for narrowing down where the noise is emanating from. top, bottom, front or rear. you need to get one and do some checks while shooting some rev's and listening to your motor. diagnosis is key.