A few times recently after getting out of the car, I hear a hissing noise near the rear axle. I look underneath, and see steam hissing from what appears to be where the muffler meets the exhaust pipe. No drippage, just hissing steam.
Shouldn't exhaust be vented out the exhaust pipe? I see exhaust venting normally when the car is running. What's causing exhaust to be pressurized?
Thanks!
Norman
'89 535i, 225000 miles, family owned... Williamsburg, VA
Oh, sure, that's what I expected. Admittedly I don't know exactly what's going on inside the exhaust system, but why is it hissing out the muffler when nothing is coming out the exhaust pipe?
'89 535i, 225000 miles, family owned... Williamsburg, VA
Could it be residual backpressure? As in, your muffler has an internal blockage and is building/holding backpressure. I have seen a muffler packed with formerly 'dry' dog food which caused the car to run like crap and sound very quiet.
It may be time to drop the muffler and see what there is to see.
Brian
The muffler has baffles in it. They make it harder for the exhaust gases to pass through. So if there is a hole in the pipe before the muffler the gases take the easier way out. Dont burn your hands, but if you put your palm close to where you think the hole is, you will feel it blowing. Maybe only a pin prick you can stop up with some exhaust putty-for now