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Water Drip from Muffler Seam

Hello! Thank you for letting me join the CarTalk community. I have a 2015 Honda Accord, V6, dual mufflers. There is a water drip from the seam closest to the exhaust pipe on my driver side muffler. There is no drip under the passenger -side muffler. There are some water droplets in both tailpipes. The weather here in Plano, Texas, has just started getting cold and that is when I noticed the water puddle under the driver-side muffler. I don’t see any weep holes. Sometimes it does not drip at all and sometimes it drips a lot. No pattern. The car isn’t driven much - I drove about 300 miles between 15 August and 15 November - I work from home, so no commute. The last time I filled up was 15 November and before that it was 15 August.

I know the water is from condensation (a natural by-product of combustion) building up in the muffler, but why is this drip on only one muffler and at one seam? Is this something I need to have my dealer check out? Is it something to be concerned about. Thank you in advance for your help and thanks again for letting me join your community. Richard

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Assuming you actually have a leak at a seam you need a muffler shop . And yes it needs to be looked at because leaking exhaust pipes can be dangerous.

Likely you don’t have a true dual exhaust system with the full pipe coming from each side of the manifold going all the way back. More likely it is a single pipe going back with a Y at the back to split off into two tail pieces. That means one pipe is longer than the other and won’t heat up as far, thus the dripping from the one. Depends on whether the system is stainless now or regular steel as to whether it will rust out faster. On my Buick with the muffler way in the back, I’d go through a muffler about every two years. Finally, the guy put a couple small drain holes in the muffler to try and drain the water out. At any rate warming the car up enough to dry the water out will help. Pretty normal though.


Hello Bing. You are correct on the piping. One pipe comes from the manifold then splits off to two muffler/tailpipes. The pipe on the passenger side is the shorter one; the pipe to the driver’s side goes across, the longer one you mentioned. The passenger side tailpipe also has less water droplets than the left one. Don’t know if it is stainless. Since I have a full warranty on the Accord, I’ll drop by and see what they want to do. Maybe they’ll drill weep holes? Like Volvo V10 said, if it is a seam leak, the muffler should be replaced under the extended warranty. Seems logical to me. Thank you both for your replies. I’ll report back when I get it fixed.

I’ll bet lunch they’re “weep holes”. Many mufflers have them, generally next to the seam at the forward end of the muffler, as that’s the lowest point.

The reason you’re only seeing it on one muffler may be simply the internal dynamics of the exhaust system. Dual exhaust systems have cross pipes that allow the gasses to follow their preferred path, the path of least resistance, and in your case that may lead to the left side when there’s low exhaust flow, like at idle. Having the system “prefer” one side when idling is perfectly normal.

You could simply back the car up onto ramps (chocked and with parking brake on) and slide under the car with a flashlight and see if you can see the weepholes.

I doubt holes of any type are allowed in mufflers. B/c if they were, exhaust gasses would be forced out of the holes under exhaust pressure, right? And all of the exhaust is supposed to come out at the tailpipe, for safety sakes. My guess, OP needs some exhaust system work done to return their vehicle to safe operating condition. One diy’er method to test of exhaust leaks mentioned here before is idle the engine & have a helper hold a board or piece of cardboard so it almost covers the tailpipe. That will force exhaust gasses out places where there are leaks, so the leaks are easier to ID.

I did look under both mufflers and could not see any weep holes. You mentioned a weep hole would be generally next to the seam at the forward end of the muffler. This drip is at the exhaust pipe end seam, not the tailpipe end if that clarifies more. ANd I have noticed those puddles under that muffler since it has gotten cooler here in Texas past couple of weeks. Thanks for the explanation of the gases and their paths in a dual pipe exhaust system.

Make sure you’re not loosing coolant.

I know newer F150’s DO have weep holes in the exhaust. I was looking at one for possible purchase and crawled under it while it was idling (yeah I’m THAT guy!). Factory holes, not rust, sputtering little water droplets out. I found it odd, but they’re there (on that model).

OP, I don’t think it’s a big deal, but if it was under warranty I’d take it in. If it’s out of warranty, and I couldn’t hear an exhaust leak, I’d let it go, personally, unless there’s a clamp or flange nearby that could be tightened.

Since it has the extended warranty, I guess I’ll take it in to the dealer and let’s see what they say. It would make more sense to me if both mufflers were dripping water droplets - then it would be a weep hole issue probably. Maybe the passenger-side exhaust gets most of the gases and is hotter so there is no dripping, and the driver-side pipes don’t get as much gases and are cooler leading to moisture build-up and dripping. Thank you all for your suggestions.

A complaint that one muffler drips more than the other won’t be well received by the dealer, should they install mufflers that drip more equally?

Despite having an extended warranty expect to pay an inspection fee for something that does not sound like a failure.

When I complained that the door lock button on my Chevy Citation’s passenger door vibrated and rattled constantly while I drove, the J.O. service manager at the dealership told me “that’s the way it’s supposed to be”. So, I told him that because I wanted everything on my brand-new Chevy to work as it is supposed to, I expected then to loosen-up the door lock button on the driver’s door in order to match the one on the passenger door.

Yes, I was taking a chance that this jerk would actually do what I suggested, but my calculated response got the desired result, and when I picked the car up, the passenger door lock button had indeed been fixed.

The dealership went out of business a couple of years later, so I was apparently not their only dissatisfied customer.

I’ve seen mufflers with tiny weep holes. You could have a small gap at the seam that isn’t supposed to be there. I don’t think it’s a big deal but have it looked at anyway.

They’re allowed, but must be aft of the passenger compartment. My '79 and ‘89 pickups’ mufflers had weep holes. My checking out what I thought was a leak in my '79 many years ago was my first introduction to weep holes.

Good one, Nevada! Cracked me up! I’ll just ask them to take a look at the dripping one. I won’t insist on a matching dripper.

Oh no, that’s the lubricant for your muffler bearings leaking out!

I’ve seen weep holes at the front seam, middle bottom or rear seam depending on make…

Great segment on Wheeler Dealers recently that showed the way dual exhaust works in some cars. The exhaust in the focus car was always from one of the two outlets unless the car was driven hard, then the second opened. It was a Mitsubishi 3000GT. So, like the folks above confirm, the exhaust is not equally distributed, hence the single leak. Keep that V6 Accord. They are not making any more of them. I loved both of mine despite the quality issues.

TwinTurbo, you cracked me up with “muffler bearing lubricant”! Good to know that weep holes can be at the seams.

Hello gorehamj. Good to know, like other members mentioned, that exhaust is not equally distribute; hence, dripping at one muffler. I like my 2015 3.5L, V6, 278 HP Accord, 360 W audio, champagne pearl color, nav, sunroof, leather, heated seats and side mirrors, and more. Plenty of acceleration for me. Major improvement over the 2003 Honda Civic 5 speed we had before it.

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