As the title suggests, I think I may have a bad rod bearing. '91 z28, 305, around 175k miles (est.)

There is a horrible metallic knocking noise coming from the engine that increases with the RPM's. The car has absolutely no power.

Now, if the car has a bad rod bearing, it's getting junked. I've spent more on this car in parts than it's worth, and I have neither the time, or interest, in tearing down the engine on this headache of a vehicle. That being said, I love my car to death, I don't want to get rid of it, nor can I afford a new car right now.

There are, however, a few things that make me wonder if it's actually a bad bearing.

For example, there is an EXTREMELY rich gas smell from the exhaust. It is dumping in far more gasoline than it should, a quarter of a tank in 5 minutes of idle, in fact. Upon giving the car any gas, it bogs down. Obviously the engine is flooding.

There's also the fact that the car worked perfectly fine when I parked it (changed the water pump, serp belt and t-stat) and after all that was done...engine knock.

The old V6 I had before this car had a bad CTS, which gave it a rich gasoline exhaust smell, and caused the car to bog down. Unfortunately, that doesn't answer what the knocking sound is. What makes me think CTS is that fact that my temp gauge reads 220+ less than a minute after start up.

OEM water pump/t-stat were used.

Does anyone have an idea, or is this car going to ruin my christmas?

 

ok i primarily work on diesels but, By fuel consumption and the sound you describe, Im thinking one (if not more) of your injector tips has broken off..The tip falls down on top of the piston causing the noise you are speaking of..Unfortunately if this is what has happened you are going to need serious engine work to fix this..Like i said i am a diesel tech, and have seen this on 7.3 liters more than once..I am by no means a great car engine mechanic but hope this helps...pull spark plugs to see what cylinder is your over fueling and go from there..good luck and keep us posted

 

What does the oil look and smell like? Oil pressure normal or reduced?