Hello, i have an 88 pickup with the 22re and it has some weird rattling sound at a certain RPM. I’m not sure if I should be worried about it or not, but it is prominent. I attached a video showing the sound. Any help would be appreciated! Thanks.

My first guess would be timing chain hitting the timing cover. And if I’m right, than yes, be concerned. If the chain rubs through to the adjacent cooling jacket you’ll empty your radiator into your oil pan. Quickly. You could pull the valve cover and look to see if the one chain guide is broken.

It’s very hard to determine what the noise is from my phone, BUT I just had my chain guides go south and had the “slap” the noise I’m hearing in the vid sounds too low, either way it doesn’t sound good, I would plan on taking a look before just going with it.

Any loss on performance? Seem sluggish at all??

Sounds like it's low on oil to me or a slight valve train noise....could possibly be a chain