hissing noise

dellstopjeep

NAXJA Forum User

Location

KUNA, ID

• May 26, 2004

• #1

when my jeep 1990 4.0 xj 4dr is running there is a hissing noise, it has always been there, my neighbors 1989 4.0 does the same thing, does anyone know what that is?? :huh:

 

9

90NHXJ

NAXJA Forum User

Location

Milton, NH

• May 26, 2004

• #2

Where's it sound like it's coming from? It could be a vacuum leak. Also the fuel pump in the gas tank can be noisy.

 

S

SouthernXJ

NAXJA Forum User

Location

South Carolina

• May 26, 2004

• #3

Gonna have to crack the hood and stick your head in there while it's running. Does it increase when your RPMs increase or is it steady?

 

8

89xj

NAXJA Forum User

Location

aston,pa

• May 26, 2004

• #4

dellstopjeep said:

when my jeep 1990 4.0 xj 4dr is running there is a hissing noise, it has always been there, my neighbors 1989 4.0 does the same thing, does anyone know what that is?? :huh:

Click to expand...

from engine bay or rear??????? my crystal ball is broken.

could be vacuum leak. brake booster could be leaking.

from the rear, it could be the fuel pump.