[elegant]

My 2008 335xi coupe was a few months old when I had my dealership where I bought it, install the BMW Performance Exhaust. Ten days ago, just two months after it was installed by them, I removed the exhaust (long story -- though nothing to do with its sound, with I love).

In the process of just starting to lower the exhaust, my friend and I immediately got soaked. And more and more water came out as it was tilted down and lowered. We were sure that when we had it on the floor, it was now empty. However, when we tipped it up, quarts of water came out of each muffler. Impossible to tell, but our best guess is that the water was originally just below the height of the bottom of the exhaust tips, i.e., that both mufflers were half filled with water.

I took the muffler system in my BMW dealership several days ago. Their parts department reviewed the situation, then today called to tell me that having lots of water in the mufflers is normal. I question this, and calls to many muffler shops in my area confirms that while most removed mufflers do have some condensation in them, it is a rarity that they are half filled with water. As one muffler shop told me today, we remove about 15 mufflers every day, and sometimes weeks go by without one being even close to half-filled with water. He did say, in fairness, "my shop doesn't remove many mufflers from turbocharged BMW's." Other muffler shops echoed that having water filled mufflers was unusual, though two shops suggested drilling a small hole in each exhaust, in the rear, about 1/4" above the bottom of each muffler, noting that many new mufflers come with drain holes

I am concerned about the longevity of halfway-water-filled mufflers, less than thrilled with the thought of carrying out 20-30 pounds of water around, and not excited about drilling a hole in each exhaust to let the water out.

Do you think that the dealership is accurate -- that this is normal and okay, and does anyone have knowledge as to whether 100% of the metal in the BMW performance exhaust is stainless, or just parts of it? What do you think about drilling drain holes? Thank you in advance for your response.

[Bimmer007]

would a high rpm WOT get rid of the water?

[DrGP]

Since they are BMW parts installed by BMW mechanics, I would make a complaint or at least a call to BMW customer relations. I don't believe that any exhaust system is meant to collect any apreciable amout of water that will not EXHAUT out of the car. Te stock system doesn't do that so the replamant exhaust should't either. I would not allow them to drill a hole in the muffler without the express blessing of BMWNA. I think you need to go over the head of your local dealer on this one.

[stressdoc]

+1 Epic fail by your dealer.
I am most curious if this is common with the Perf exhaust, as it is high on my wish list.

[bsamoul]

Maybe they decided to install your exhaust in a lake.


But seriously, it is unusual to have that much water in a muffler

[chazzz]

I think your car was parked overnight, every night and it builds up the condensation inside of muffler??

[rmorin49]

This why it is important to to drive your car enough to completely heat up the exhaust system thus minimizing the build up of water in the muffler or mufflers.

[clickclickboom]

A product of combustion is water. The water vapor cools and condenses in a cold muffler. When the muffler warms the vapor doesn't condense add passes out the pipe along with water that was in the muffler. Most mufflers have a tiny hole to allow water to drip out so it doesn't build up.

[vAnt826]

Very abnormal. With that much water I am very sure your exhaust is losing performance.

[Dillusion]

usually the exhaust sytems are installed on an angle inside and at the tips. I can literally point my hose at my tips when washing my car and the water will come gushing right back out.

[Spoolin335]

since exhaust gases are like 500C im surprised it didnt evaporate within a few minutes.

[Quasimodem]

This is a built-in feature in the latest BMWs. It is there in case you get lost and run out of gas in the desert and have no source of water for survival.

[Aurora Bearialis]

Originally Posted by Dillusion

usually the exhaust sytems are installed on an angle inside and at the tips. I can literally point my hose at my tips when washing my car and the water will come gushing right back out.

I burnt my leg on my exhaust when getting something out of my trunk so it gets really hot and I can't see water being in there without evaporating

[e90fanatic]

btw can u take pics of ur performance exhaust? i have not yet seen one on a coupe!

[ezatnova]

Originally Posted by e90fanatic

btw can u take pics of ur performance exhaust? i have not yet seen one on a coupe!

http://www.e90post.com/forums/showth...exhaust&page=3

[mike-y]

Do you have a short commute in the morning, or do you take frequent short trips? On short trips, the exhaust doesn't get hot enough to evaporate the condensation that forms on cold starts, so over time, you can get water build up. This is the first time I've heard of so much water collecting inside the mufflers though.

Also, maybe some water got sprayed in there during a car wash? If your mufflers don't drain, it could be really easy to spray water into them.

[mmm def]

my E90 stock exhaust leaked about a half gallon of water when I removed it a few weeks ago..and it had only been on my car for 6 months.