Muffler rust hole at the seam is dripping water

[SalvadorP]

I've been fixing issues with the exhaust systems the last few days but I've decided to make a new post because this is a separate issue I just found.

Middle muffler has 2 rust cracks at the bottom along the seam, 1 at the front and another at the back. Cat has a pretty good crack too.
I patched the 3 leaks with exhaust putty that claims to hold up to 1500ºc.
After a few hours drying both the back crack on the muffler and the cat leak were looking good. When I inspected the front crack on the muffler I noticed the putty was still wet. Upon further inspection and after pressing on the leak area it started dripping water pretty profusely. Turns out there was water inside the middle muffler and it made rust hole on both ends, but because the car was not completely level but facing down, the water gathered there and only prevented the putty from drying at the front seam.

Has anyone have this happen before?

Tonight I parked the car facing up and after it's cold I'll apply a bit more putty and let it dry overnight.

Car was vibrating like hell at idle and 1500rpm. Was making a weird ratlling noise that sounded like tranny or clutch. Still is making both, but is much, much better. Maybe patching the other leak will fix the problem entirely.

Link to pic of the crack: https://imgur.com/5gscYgy

[griston64]

Originally Posted by SalvadorP

I've been fixing issues with the exhaust systems the last few days but I've decided to make a new post because this is a separate issue I just found.

Middle muffler has 2 rust cracks at the bottom along the seam, 1 at the front and another at the back. Cat has a pretty good crack too.
I patched the 3 leaks with exhaust putty that claims to hold up to 1500ºc.
After a few hours drying both the back crack on the muffler and the cat leak were looking good. When I inspected the front crack on the muffler I noticed the putty was still wet. Upon further inspection and after pressing on the leak area it started dripping water pretty profusely. Turns out there was water inside the middle muffler and it made rust hole on both ends, but because the car was not completely level but facing down, the water gathered there and only prevented the putty from drying at the front seam.

Has anyone have this happen before?

Tonight I parked the car facing up and after it's cold I'll apply a bit more putty and let it dry overnight.

Car was vibrating like hell at idle and 1500rpm. Was making a weird ratlling noise that sounded like tranny or clutch. Still is making both, but is much, much better. Maybe patching the other leak will fix the problem entirely.

Link to pic of the crack: https://imgur.com/5gscYgy

It's because exhausts rust from the inside out. You will be forever patching holes up as once you seal one another one appears. You can get a complete cat back exhaust from FRF in the UK for under £200 posted

[SalvadorP]

Originally Posted by griston64

It's because exhausts rust from the inside out. You will be forever patching holes up as once you seal one another one appears. You can get a complete cat back exhaust from FRF in the UK for under £200 posted

Thanks for the tip. I was looking at the ones on Skandix. Can you send me a link? Can't find it on google. Sorry if it's well known. I never heard of it.

I will need to replace the cat eventually too. It has a crack also. But I'm going back to Barcelona this weekend and there I don't have a place to work so it will have to hold up for at least a year. My thought is, if it fails inspection (because of cat), I'll fix it, if it passes I'll patch it until I come back to Portugal.

[griston64]

https://www.frfvolvo.co.uk/

Quote code C3 for forum discount

[TonyS9]

Engines produce water when they burn fuel, its normal. The exhuast is very acidic and will corrode an mild steel exhaust in a few years if you only do low mileage, as many 940 do these days. With higher mileage they dry out and don't rot as much.
I was welding the ehaust pretty regularily. For me the solution was to move to stainless with a full down-pipe back custom system for about £500.

[tofufi]

Originally Posted by TonyS9

For me the solution was to move to stainless with a full down-pipe back custom system for about £500.

Stainless definitely the way to go if you plan to keep the car long term.

I've got stainless exhausts (or part stainless) on 7 of my 8 cars.

The 8th will have one once I manage to justify the expense of building a stainless exhaust for a 5.5 V8 with tubular manifolds and huge silencers.

If you're able to MIG weld making your own from the downpipe back is pretty easy using stainless welding wire, and stainless tube and silencers bought from eBay.

[Rversteeg]

I understood that the quality of exhaust systems is so quetionable nowadays, that it is not uncommon that they only last for 3 to 4 years. I was so fed up with exchanging that I also went for stainless steel from Ferrita. The standard one, not the sports version. Perfect fit, good dampening and nice appearance. A bit more expensive, but for me worth it.

[SalvadorP]

Tried applying putty to exhaust and cat crack. It cracks right after. Doesn't hold even from a small ride, even after drying overnight.
Bought another brand of putty, but I'm not expecting anything at this point. Especially because I'll be applying it over the other...

I guess I'll have to accept a noisy exhaust until I change cat and exhaust... That's gonna hurt. Where should I look for a cat? Do I have to look especifically for a 940 catalytic converter? Or do some others fit?

I wonder if I had brought it to a welder if he couldn't have solved the cat issue, since it was a crack on the weld. Now that already botched it with putty I am probably completely lost!? No way to remove it right?

[griston64]

Originally Posted by SalvadorP

Tried applying putty to exhaust and cat crack. It cracks right after. Doesn't hold even from a small ride, even after drying overnight.
Bought another brand of putty, but I'm not expecting anything at this point. Especially because I'll be applying it over the other...

I guess I'll have to accept a noisy exhaust until I change cat and exhaust... That's gonna hurt. Where should I look for a cat? Do I have to look especifically for a 940 catalytic converter? Or do some others fit?

I wonder if I had brought it to a welder if he couldn't have solved the cat issue, since it was a crack on the weld. Now that already botched it with putty I am probably completely lost!? No way to remove it right?

You can get an aftermarket cat for a 940 for £40

[SalvadorP]

Originally Posted by griston64

You can get an aftermarket cat for a 940 for £40

Are they worth it? The cheapest I found was 150 on ebay and I was reading online people saying they were crap.

If it was you, where would you buy it or what price range would you go for? I was looking at Skandix. They go for 350€ :s