noise coming from under the hood near the brake fluid container

when i start the car cold i hear a strong vibrating noise coming from under the hood. the noise is directly in front of the drivers position. problem is it only makes the noise when im driving and at about 1k-1.5k rpms so i cant hear it at idle(noise goes away over ~1800 rpm's)

when i look under the hood it seems like its coming from under a black cover thats right near the brake fluid container(sorry i dont know names of parts)

after a few minutes the noise goes away.

i just had the head gasket done. the noise was there before it but now its louder.


any help?


1990 4runner V6 115k miles auto tranny

Hard to know without hearing it.

If the 90 has a crossover exhaust behind the motor but above the tranny it has a heat sheild that can break its spot welds.
Try putting a screwdriver blade in between the sheild and pipe to see if it stops.
If it does a quick but temporary (less temporary in wet weather) is to take a wad of steel wool and cram it between the pipe and sheild that will keep it from rattling for a while, mine actually lasted a year.

this was just a wild guess based on first hand experience.

Good Luck, please post if you find out what it was, curious.

Check the mounting bracket for the main exhaust pipe right out of the driver side header there is a clamp to the bracket attached at the bell housing. Best viewed from ground up.

This sounds similar to my symptoms but I replaced the crossover pipe as well....

http://www.automotiveforums.com/vbulletin/showthread.php?t=221616