Metlic53

I had a vacuum leak that was causing the problem when trying to switch the air vents to front circulation, it would whistle, i found the leak and fixed it and it worked for 3 months. it just went out again and i've checked every vacuum known to man on this XJ, is there anything else i could check? I don't really want a shop to take the entire dash out and spend a crap load of money for it.

Andrew_1122

I had the exact same problem with my jeep. Another guy recommended that i check the lines under the battery. I would start there and also check the vacuum canister that you can access under the battery from the bottem. a black canister. Mine had 2 massive holes in it. Hopefully your problem lies here.

Metlic53

Thanks alot!!! Hopefully that is what it is. I'm tired of looking for it.

Andrew_1122

No prob I actually fixed mine today lol. You can access the canister from below. Remove the 3 10mm bolts and you should have access.

ZachsXJ

most likely thats your issue, the line between the canister and the selector lever in the cab.

maverickdan

had same problem with mine, had a crack in the hvac controls replaced, fixed the problem

Metlic53

mine XJ is a 97 model, i dont know if it is different or not but there is nothing underneath the battery tray.......

Metlic53

bump

93XJLI

bump? you have a vacuum leak. find it. when my 93 did this there was some check valve that went bad and faulted shut, cutting off vacuum. it was near the firewall somewhere. if you pop the line off with the motor running and it doesnt go PSSSSSHHHHHHH then theres no pressure, follow the line back til you find the fitting (or crack in the line) thats at fault, and replace as necessary. if you really think you looked everywhere, its a line behind the dash. there also one behind the HVAC controls and one near the blower motor resistor.

Metlic53

i have plenty of pressure coming out of all my lines, it actually sticks to my hand. i'll keep looking.
yes bump

winston427

The vacuum resevoir is located inside the front bumper on the passenger side. It may be hidden by the inner fender liner.

mycherokee

So my vacuum canister only has 2 vacuum line sgoing into it and on the other end they are missing and there are 2 holes in it. I guess thats why my vents dont work? lol Now I just need to figure out where they actually go to. And what to buy.

Metlic53

i have bushwacker flares on it and there is nothing there. is it like a round bubble looking thing that has i think 2 lines going into it? if so there is nothing wrong with that, i thought that was for the 4wd though.

Metlic53

i just have that sitting up by all my computer fuses. does it need to be faced in a certain position?

Rmart30

Ive had 4 Xjs with vent problems and they all turned out to be vacuum leaks.
. Either they didnt change positions or blew partially from all locations.
1 was the vacuum canister cracked, 2 were the large line running by battery tray cracked/broken, another was a smaller vacuum line broken under the hood.