1G Eclipse '91 Noises--need help figuring it out.

[romeroom]

I need help figuring out 2 different noises coming from under the hood.

1. When start, there is a squeal noise similar to when there is a bad belt or idler pully on old cars. After just a few seconds or if I rev it up a little the noise goes away. The alternator was replaced a few months ago. The belt looks fine, and honestly does not feel very tight. Should I tighten or loosen it?

2. There is a metallic (valve sounding) rattle during acceleration; it stops during cruise. I've noticed it getting a bit louder. The sound is like what I remember an engine doing when the timing was off (We're going back to 1970+. At that time manually adjusting the timing by turning the distributor cap would make that noise.

Thoughts?

 

[dwb]

Please fill out a vehicle profile so we know what car and mod list we're talking about. Manual or automatic? Turbo or NA?

A video of your issue would help us understand better.

1. When start, there is a squeal noise similar to when there is a bad belt or idler pully on old cars. After just a few seconds or if I rev it up a little the noise goes away. The alternator was replaced a few months ago. The belt looks fine, and honestly does not feel very tight. Should I tighten or loosen it?

Tighten the accessory belts and see if it helps. Otherwise it might be something like the AC tensioner pulley (if you still have it installed). Could also be a timing belt pulley - when was the timing belt replaced last?

2. There is a metallic (valve sounding) rattle during acceleration; it stops during cruise. I've noticed it getting a bit louder. The sound is like what I remember an engine doing when the timing was off (We're going back to 1970+. At that time manually adjusting the timing by turning the distributor cap would make that noise.

Is it one side of the engine or the other? The 4g63s are naturally pretty chatty so you might be hearing something like the HLAs. I hope you have verified the oil level.