Muffler water drain holes

[dom14]

Hi Guys,

I'm beginning to think that I might have created a problem, rather than solving a problem,
when I repaired my leaking muffler box couple of years ago with welding.

Basically, the muffler was leaking and making that annoying noise.
So, I went under it and as it shows in the picture, I spotted the problem areas.

The only thing I didn't know back then was that there's a thing called "Muffler weep holes"
So, there was a definite rust deterioration on the side wall as in the picture, which I welded and repaired,
which I believe I did the right thing at the right time.

Then at the bottom I noticed four holes as well. At least three of the holes appeared to be leaking exhaust gas,
'cos I could see the soot around the holes. So, I thought I should repair them as well.
Even though they appear to be holes, I couldn't actually see a hole into the inside of the muffler.
It was more like rusted little circle, even after wire brushing it.
Any way, I filled it with mig weld and cleaned and sprayed some heat resistant paint to make it look good.
It's been going ok for almost two years, until few months back I just had to touch up the bottom ones again.

Now, I got to know about the "weep holes" to drain the exhaust moisture that get trapped in the muffler, I began
to think that I must have blocked the weep holes.

Muffler is still going fine as far as I can see. I've attached a video as well of the exhaust, showing little bit of water dripping
form the end of it, while the engine was running(this morning). The water was still dripping after 5-10 minutes of engine running,
though today was a very very cold morning(zero degrees)

https://www.youtube.com/watch?v=1h66gPBF_Hg

Now, I'm bit worried whether I've blocked the "weep holes" and created a problem by causing the muffler to gather water and
cause corrosion, blockage and eventual blow up.

What should I do?!

Should I drill a small hole in one of the blocked hole spots to allow the water weeping thing to happen again?

Any advice would be great.

Thanx

[Bloodyaussie]

Time for a new muffler.... that thing would be stuffed inside.

[dom14]

Time for a new muffler.... that thing would be stuffed inside.

It appears to be going ok. I hear no noise or rattling, etc.

I blew the inside with compressed air last year.
I couldn't feel a resistance. No crap came from inside either.

Is there a backyard method to test a dying muffler?

I reckon I should go back to my vacuum tester?
I wouldn't mind keeping it going for a while, if that's doable.

Thanx

[Bloodyaussie]

Start the car and get someone to bloke the end of the exhaust with a rag while you have a listen for any leaks around the muffler..

[Cuppa]

My opinion fwiw...... I’d be inclined to continue using it as is until it rusts out ....... & then get a new one. The fact that it rusted 2 years ago suggests it was on it’s way out, & you have managed to keep it going. Any extra time you get on it now is a bonus, so not really worth stuffing around with it now.

[dom14]

Start the car and get someone to bloke the end of the exhaust with a rag while you have a listen for any leaks around the muffler..

Hi mate,
There're no leaks at the moment. I've fixed all the exhaust leaks. There were minor ones from flanges.
But, not so minor, 'cos my misfiring and backfiring problems don't seem to appear after I fixed all the very small exhaust leaks
(one in manifold flange gasket, another in the flange gasket after that).
I also blocked the vent on the top of the TVV(Thermal Vacuum Valve) with sticky tape.
If you've followed my previous thread, you may remember I had the TVV issue with it's venting from the top of the valve.
It's not suppose to do that I reckon. So, I sticky taped it.
I'm not 100% sure whether my misfiring was fixed by fixing those exhaust leaks or 'fixing' the TVV.
I'll start another thread to discuss that.
I reckon I'm just gonna do the vacuum test at the intake again and see if it shows any exhaust blockage.
But, the compressed air test I did(last year in December though) was a good one, 'cos I set it up in a way to let go a fair
bit of compressed air into the muffler. It didn't blow any crap, nor it showed any resistance.
That's why I like to keep this muffler going for a while.
A new one is usually more expensive than extractors themselves, so I reckon I should try to get as much life as possible from
this old exhaust.
As a matter of fact, two years ago when I repaired the leaks, I did a 'good' job with it by painting it to look like a brand new one.

[dom14]

My opinion fwiw...... I’d be inclined to continue using it as is until it rusts out ....... & then get a new one. The fact that it rusted 2 years ago suggests it was on it’s way out, & you have managed to keep it going. Any extra time you get on it now is a bonus, so not really worth stuffing around with it now.

Hey Cuppa,
Should I open the hole by drilling it, that was apparently meant as a water weep hole?
At least one hole, just to extend it's life bit longer?
BTW, aftermarket mufflers(many of them) don't seem to have weep holes.
Why is that? I'm wondering.
Thanx

[Throbbinhood]

Never seen weep holes on any of my mufflers. Got a nice little one though where a rock decided to poke it's head in and take a look around.

[dom14]

Never seen weep holes on any of my mufflers. Got a nice little one though where a rock decided to poke it's head in and take a look around.

i would fill the hole with either weld or some of the heat resistant putty stuff(Maniseal, etc). Small hole can turn into a big hole in no time, as in the case of my muffler.
I was able to repair it with fair bit of patience and a combination of mig and arc welding(yes, I used an arc welder as well, don't ask me how I manage that. ).
It's a real PITA to weld thin sheet metal used in mufflers, even with a mig welder. It's pretty easy to blow a bigger hole, rather than filling the existing leak hole.
IMO, the ideal welder to repair mufflers is TIG. But, TIG doesn't work with rusty surfaces, so needs heaps of wirebrushing and removing all the rust contaminants first.
I haven't done that yet. It's easy to write about it, rather than doing it.

[Cuppa]

Hey Cuppa,
Should I open the hole by drilling it, that was apparently meant as a water weep hole?
At least one hole, just to extend it's life bit longer?
BTW, aftermarket mufflers(many of them) don't seem to have weep holes.
Why is that? I'm wondering.
Thanx

I’m no expert, but I also can’t recall having any weep holes in a car muffler before, so I’d be inclined to stick with the instinct you had when you welded them up. I have had a weep hole in a mototorcycle exhaust before, a Moto Guzzi le Mans with aftermarket Italian pipes, but from memory it was at the lowest point of the pipe, not in the muffler, & then only because the mufflers were upswept. They still rusted out, but the pommie habit of salting the roads, in combination with crap Italian chrome probably had a lot to do with that.