Deleted my previous thread and am putting it here. I noticed a quick/constant pulsating hiss coming from the rear axle area under the car. I had my diff taken out to replace bushings so they had to take apart the exhaust from the Y pipe to access it. Wondering if it wasn't put together properly? What would an exhaust leak from that area sound like? What does the fuel pump sound like?

 

That sounds like an exhaust leak. Exhaust leaks can sound like "puffs" of air constantly pulsing like you describe. Get down under the car while it's running and see if you can feel the leak with your hand. Put your hand close to the flanges on the exhaust and see if you feel air coming out. If you feel a leak at a flange, tighten the bolts up in alternating patters from side to side until the leak stops.


The fuel pump sounds like a constant hum, and if your ears are good enough, you can just barely hear the high pitched whine of the pump. It will not be a pulsing sound.

 

Mine does this too. I thought it was exhaust leak but shop couldn’t find a leak when I took it 2 weeks ago. It sounds like hissing sound that seems to come from rear passenger qtr panel area. There isn’t really anything else it could than an exhaust leak giving it’s coming from behind me. I know my exhaust is super rusty and crappy b/ I live on the beach so that could be the reason for me.

 

Yeah I'm probably going to try to take it in to the shop since they warranty their work after installs. I never heard this before.

 

OP, you did replace the gaskets when reinstalling the exhaust? It sounds like you had a shop do this. If so, they didn't check for exhaust leaks before releasing the car. I'd expect them to correct the issue without charging you additional labor. Charging you for exhaust gaskets would be reasonable.

 

I did have a shop do the work, so I'm guessing they just reused whatever was there. Do the gaskets need to be replaced each time the exhaust is taken apart?

 

Depends on their condition. They should of tested for leaks and proceeded accordingly IMO.