2003 Jeep Liberty 3.7l sport has hissing noise from rear

I don't have a hissing, but am failing the OBD with a "small leak in the EVS", and I'm trying to find the leak myself. It's a 2003 Liberty.

Your pictures are great, but a little too low resolution for me to see completely. Where did these come from? I didn't see anything about the EVS in Chilton's.

Thanks.

Thanks. I swapped the cap with my Caravan. Luckily they're the same. But the problem is still with the Liberty. The neck looks good to me, but I'm no expert either.

I did follow some lines that came down from the filler tube. I'm not sure I followed the right ones, as they disappear for a bit, but it looked, from your picture, like they went into the leak detection pump. A line coming out of that pump is joined by a rubber connection to another line, and that rubber sleeve was split. I gooped it up with Shoe-Goo (the best stuff I had on hand :-)) and am now waiting to see if anything comes of that.

Otherwise, I may leave it to the pros. I'm not a mechanic in any sense of the word and wouldn't know where to rent a smoke machine, nor what to do with it if I could get one. And dropping the tank doesn't look like my kind of fun :-(

My jeep had this same exact noise- people would stop me to tell me my tire is going down. Really fast! I took it to my jeep dealer, while getting a oil change, and they replaced a vaccum hose, it was a @2.00 part that they did not even charge me for! Wished I knew exactly what hose was called or where it was located-

Hi everyone, I have the same problem, the hissing noise and found where it's coming from...but I don't know what it is to replace it. I've circled it here in red. It's a hose coming out of the LDP, and in between that hose and another, there's a black "connector" that is cracked on both ends. When I cover the cracks with my thumb, the hissing all but stops.

If you look at the images uploaded by ServiceWriter, 3rd image, the hose coming out of the LDP on the left near the arrow for #15, follow that to the right and you'll see the "connector".

Anyone know what that "connector" is called?

Thanks!

Tim

I have the same hissing sound with my 2007 Jeep Liberty and when I did a smoke tested it (using something that smoked) the smoke was drawn up to the top of my gas tank. I felt around up there and could feel air being drawn but I couldn't find the exact hole. I tried to smoke the fuel filler line and I couldn't keep the smoke contained enough as it was being sucked towards the top of the fuel tank. I guess I'm going to have to drop the fuel tank to find it. There is not enough room to see never mind get your fingers in. Those last photos on mine pass through the frame cross member. This has been going on for a year with a gascap light and a P0456&PD, P0455 recently. Now the engine misfires and diesels when the engine warms up. I have replaced all the hoses and some pipe from the solenoid to the engine and down under near the O2 sensor along with the solenoid at a previous time.

My 2002 Jeep Liberty Renegade had the same hissing noise coming from the rear of the vehicle & as others had mentioned, people were frequently saying I had a tire going flat. Ended up being the vacuum line from the engine compartment to the LDP had split. Shop Tech. Found the problem quickly. Thanks for posting info like this to assist others!