Hey all! I'm new to this forum so I'm not sure if I'm posting this in the right spot. I need help identifying an engine noise. It's driving me crazy and it's been going on for about 3 weeks. I think I've isolated it to the intake. It sorta sounds like air moving through fluid. It doesn't sound metallic in nature. I took a pvc pipe, stuck it to my ear, put it on every part of the engine and the intake is where it's the loudest. The noise doesn't seem to change while revving it, and I can't hear it going down the road but then again road noise, I think it's drowning it out. So here's what I've done so far to try and fix/find the noise. I pressure checked the radiator and noticed it wasn't holding the the pressure. I couldn't find the leak, but I have been losing a small amount of coolant over the past month or so. I also noticed a small oil leak on the block near cylinder 6. So I thought maybe the lower intake gasket might be leaking. Yesterday, I replaced the lower intake gasket, valve cover gaskets and upper intake gaskets on the plenum. (Cleaned all mating surfaces) There was a leak on the left side near the back. I also flushed the coolant system checked all the hoses and thermostat, everything looked good. Today I start it up and the noise is still there! This is a very well cared for jeep. It has 168k on the odometer, oil has always been changed every 3k, all scheduled maintenance has been done on time. The oil has 2k on it right now, I've included a picture of what the oil looks like.
