So I have a 1996 Z28 with an engine knock. I compared the noise to some videos on youtube and I thought it may have been a spun bearing. So I drained the oil to look for metal shavings and didn't find any but there was gas mixed in the oil. The check engine light is flashing which throws the code for random cylinder misfire. I unplugged each spark plug wire individually but the knock never went away no matter which one was unplugged. The optispark is filthy and has a brown liquid coming from it. A mechanic friend of mine listened to the video I sent him and he thinks it may be a twisted connecting rod in which there wouldn't necessarily be any metal shavings in the oil. Any suggestions?

Here is the address to the video on youtube if you want to take a look:

http://youtu.be/TLvh90_x1Qs

 

Fuel in oil? Stuck injector? Did you check compression? Rod knock?

 

Fuel in the crankcase USUALLY means you got unburnt fuel washing down the cylider.

As mentioned above, the likely culprit is a stuck (open) injector. The injector is continuously dumping fuel into the combustion chamber.....way too much fuel to get burnt.....the excess fuel is forced past the rings, doen the cylinder and into the crankcase with the oil.

The oil is diluted and this can very easily result in a spun rod bearing (the noise you're hearing....

If it were my engine, I'd pull it and rebuild it. I'd also have all the injectors flow tested to determine which one(s) are bad.....should be able to get them rebuilt as well. Those that are beyond repair can be replaced.

But in any case......the knock you have is the engine calling you for a rebuild.

KW.

 

The noise that you are hearing is opportunity knocking !!!
if you listen real close you can it hear it saying cam , heads , 383
I have seen used LT1 engines on craiglist for 600 dollars and installation from 600-1200 dollars