First off I have an ap1(00) with 75k and recently I started hearing a metallic rattle coming from my motor starting at about 3.5-4k to about vtec, it may rattle until redline but my car is so loud that i can't hear it beyond that. It also sounds like It's coming from the exhaust side. I think it's a cracked retainer or bent valve since I was going 80+ an. Shifted into second gear . The car idles fine and runs great still so I hope it isn't a bent valve. Amy input or ideas would be great, thanks.

 

Make a video

 

I'll try to that soon but u might not be able to hear it from inside the car through the recording. It's really prominent from 4-5k rpm at 50% or more throttle

 

I would get a compression test first. If any cylinder has low compression, do a leakdown test to find out if it's a bent valve (s). I would start here. Hope things turn out fine![:

 

Thanks I'll probably start here!

 

Yeah, you should also check your retainers by looking at any sunken valve stems just to make sure you dont have any broken retainers.

 

Yeah, you should also check your retainers by looking at any sunken valve stems just to make sure you dont have any broken retainers.
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Yeah I initially thought it was broken retainers since I did over-rev the s**t out of it

 

I found something like 11/16 of mine were cracked. A couple people made a big point of looking for bent valves. Well the shop that did the work toasted my motor so i got to take the old one apart. I didn't have a single bent valve with 11 cracked keepers. Takes a lot to bend these valves.

 

keepers? I thought you would say retainers. How do you know it takes a lot to bend valves?

 

Broken retainers make no noise at all.