How to secretly sabotage an engine

Kys

Come on dude give me something real. This guy has been a knife in my ass for years. He can't even afford the fucking thing

Loosen his oil pan drain plug just enough so that it will come out the rest of the way while driving.
Or loosen his oil filter so it does the same.
you could also take out his spark plugs, pour gas in a few of the cylinders and then put everything back together. When he turns the car on it should cause detonation.

Well I don't wanna kill him. I want to do it subtly

I'm tempted

Why fuck with his vehicle then? Just take a shit on him while he's sleeping or something.

I don't want him to know I did anything. The dudes psycho. He'd stab me or some shit.

Lol you're a fucking idiot

what else is new

Sounds like you deserve it. Don't fuck with somebody's vehicle.