Ok , I have the headers all done and fixed the leak I had by the cat.I had the jeep running and it purrs like a kitten , but then I hear like a popping sound , tracked it down and it is coming from this thing , it looks like some kind of electronic vacuum control solenoid? It has a plug so it has power to it , and 2 hoses one goes to the throttle body , the other one I am not sure where it goes , it disappears into the front end by the radiator. The first pic shows where the bottom hose goes to on the TB , the second pic is the unit itself.I unplugged it and it stopped the popping it was making , so I don't know if this thing is supposed to do this or if it has gone bad , but it doesn't affect the jeep.








Oh , it sits bolted to the inner fender panel on the driver side near the air box.You can pull it up as it has a rubber mount that sits on the part bolted to the fender.If anyone with the 5.2 can take a look while their jeep is running and see if it makes any kind of noise so I know if this is normal or not it would be appreciated. I have no idea what it would fall under in the manual , so would be a pita to try and find.

That device is the evaporative emissions system Purge Solenoid. It operates on a pulse width modulated output from the PCM. The ticking clock type noises it makes are normally heard as the vehicle is warming up. The noise can be bothersome to some people, as it may be audable from inside the Jeep. If it is, you can add a second rubber isolator to it's mount, something I used to do regularly as a Jeep Dealer tech.

Thanks Marty , I had no idea what it does.I wasn't driving the jeep , just had the hood open with it running while I was listening for exhaust leaks from the headers.I had the jeep running for about 25 minutes so it was all nice and hot , and I happened to hear that thing clicking away.Unplug the wire and it stopped but there was no change to the jeep at all.

so it sounds like it is normal for that to make some noise , I have never heard it from inside the jeep.As long as the jeep keeps purring like a kitten I guess that solenoid works fine.