What's are the symptoms of BENT RODS and how does it sound like?

[10kredline]

There's this sound coming from the engine and I can't seem to figure out what it is. At first, I thought it was the fan rubbing against something but it wasn't and seems like it's coming from the internals of the engine. Also the idle isn't smooth, its like having misfires but very minimal and I changed all the spark plugs along with new 2.0T coilpacks. Under part throttle, it bogs when I release the gas. Some hesitation during WOT. Just wondering what are the symptoms of a bent rod or valves? Been searching but can't really find the answer..

Specs:
1.8TQM AEB: FT21, UM stage 3 630cc, 034 2.0T conversion, stock internals...

Edit: I'll upload a video tomorrow.

[redline380]

Bent valves would be an easy diagnosis, just do a compression test. A bent rod is a little harder to diagnose without the head off. But I would remove the plugs and stick a skinny rod attached to a depth gauge. This will let you know which hole isn't coming completely to the top of the stroke, if any.

[BlueBoostedAudi]

Have u tried to take a screw driver and stick the flat head on block/head and then take the handle hold it up against your ear and listen to it run. That should help u hear where the sounds are coming from.

[kruftindustries]

I haven't had a bent rod in one of these engines but last time I did, it wasn't firing on that cylinder. It might be worth it to pull the head or at the very least borrow a borescope from oreillys and have a look before driving the destruction home lol

[Seerlah]

Bent valves would be an easy diagnosis, just do a compression test. A bent rod is a little harder to diagnose without the head off. But I would remove the plugs and stick a skinny rod attached to a depth gauge. This will let you know which hole isn't coming completely to the top of the stroke, if any.

This!

But motors can run on bent rods. And bent rods don't make any noticeable sounds in particular. If you suspect the rod possibly hitting something else internally, the rod would have snapped by the time it had any chance of doing that (so I would think, especially with ~300ctq at a minimum with your setup). Maybe something else came loose internally. Happens a lot, like a piece of the plastic oil pump tensioner for example. Post videos and we can help further. Till then, all we can do is conjecture.