[stevebuick23]

Recently my 1997 Cadillac STS, has been making odd noises.

When I'm accelerating under a heavier throttle, in first gear, the car will make a odd very loud intake noise from around 2800 RPM-5500 RPM where it will stop for the last littl ebit of first gear. Its not apparent in the other gears either.

The only thing that I've done to the car was change the upper dogbone engine mounts, and added tranny conditioner to the car. (about 1000 km on it already though, was making the noise about 500 km after the conditioner).

I can't identify whether its on the right or left side of the engine bay. Its not the airbox, i've tried removing it and it still creates the noise when accelerating.

Please share any insight. I'm worried its going to cause damage. I might add that there is no noticable drop in performance either.

STeve

 

[cadillac_tech]

Maybe your exhaust is grounding out on the brace under the middle of the car. Typically happens on hard accel and changes or goes away with changes in engine load.

 

[z06bigbird]

Check exhaust manifold. If leaking, you will get noise and discoloration around area(s) of exhaust leak.

Most likely, grounding, though, as other member indicated.

 

[stevebuick23]

It only happens when the vehicle is in gear, and only in 1st gear, and sometimes when it hits into second. I'm thinking its something hitting something. I'll have to throw it on the lift one of these days I guess