I have a 88 k5 w/350, yesterday i was sitting at a stop sign when i started getting a knock from under the hood. It only happens when its in drive and the engine is hot. Any ideas or suggestions?

 

What weight oil are you running? How is your oil pressure? Is it really a knock or more of a tap?

 

I'm running 10w30, it's a knock. when it happens i can feel it in the brake pedal so i know its internal. I'm going to open it up this weekend and see what i find so i'm crossing my fingers.

 

Well just an update, i had a broken wrist pin and ended up getting a crate motor from jasper. I ended up replacing alot of odds and ends while i was under there and damn shes running better then ever.

 

Just curious, How did you diagnose it was the wristpin?
Might come in handy some day.

 

The engine was disassembled, i knew it was something internal but I didn't know what till it was taken apart. It's weird though cause it would come and go it was never consistant but it is very noticeable and you can feel the vibration through the brake pedal.

 

could it be torque converter bolts getting loose?

 

I was going to say, it sounds like torque converter.

 

I did see the cylinder wall scored up and the mechanic that did the swap showed me the broken pieces, but know my question is would it have been the torque converter bolts? I know a chevy 350 is pretty common stuff around a shop.

Would there have been anything other then the knock to give me an indication? I know its kind of a moot point at this stage but just for curiosity sake.