Strange sound on deacceleration

[Ubertino]

I'm looking at a '02 wrx 97k, a few mods (find me one that doesn't have any, and I'll buy it) that on test drive is solid, drives well, etc. However, I noticed that when I was deaccelerating with the car in gear (not engine braking) that there is strange sound coming from the engine compartment. Not a grinding in the metalic sense, but only there on the deaccel, not on acceleration. I'm thinking it might be the timing belt/tensioner, not sure. Obviously I'll have the dealer investigate before I buy, but I would like to arm myself with knowledge first if possible.

Second question, piggie back: what possible tests can I do to figure what kind of shape the transmission is in (manual). I know the whole glass thing, I've done me research, search is my friend, etc. Nowhere does it say how to check and see what kind of condition the tranmission is in.

I'd love any input.

Thanks!

[SaskWRX]

Bump. Think this is my problem as well. Live up in Saskatoon, Canada. Really cold lately (close to -40!!!) but have noticed this noise lately as well. Almost feels like the noise is coming from the turbo. Not sure if lubrication or such might be a problem as well. Maybe the oils used aren't viscous enough for this cold weather? Will check my belt as soon as the garage warms up.

[garfunkle187]

hey, Saskatoon STI owner here, mechanic too. Can you give me a better i dea of the kinda noise you're getting? Also are you sure it's coming from the engine? When it's really cold here the diffs can sometimes make a noise under deceleration.

Anyhow, let me know