Get the sound? Was crusing home on a 300 mile trip, all fluid levels good then all of a sudden this loud noise. Stopped car had to get towed home verry little power what was this and is it fixable? what do you think?
where was the clank coming from? engine i am assuming.... it is hard to say exactly what it is. First off everything is fixable if the car was still running and just lacking power then you havent thrown a rod yet. It might be your timing chain...something like a broken guide or tensioner allowing the cam timing to slip and that would cut down your compression and your power or a broken valve. If you think it is internal as it sounds it is....then pull off the valve cover and inspect the rockers and the cam sprocket....if you dont find anything wrond there pull the front cover....nothing there pull off the head. with the head off you can see the heads of the pistons to see if anything is striking them...you can then pull the engine and check for rod/crank damage.....or you could be lucky and just had something break off you clutch....there are a million things that could go clank clank clank...does the engine run rough? spool up rough? is it turbo'd?
If it sounds like valve train noise look at the lash pads. In the past 2 weeks 2 l28's come in the shop I work at that have had their lash pads fall/break off. It makes a loud clacking noise and the car will missfire bad causing a majoor decrease in power.