How to fix your car exhaust, without welding or power tools.

The old clunker's exhaust was blowing a bit, so I sealed it.

Then it fell off. It had rusted right through between the catalytic converter and the silencer.

"You know what you're going to have to do, don't you?", said Kitewife.

"Fix it?"

"No, write an Instructable!"

Step 1 Materials and tools.

This is a fairly simple job (it only took me half an hour), but you do need some specialist materials:

• Wheel ramps or axle stands. Do NOT attempt any jobs underneath a car supported just by a jack. People die like that.
• Eye protection _{(unless you enjoy rust, dirt and toxic chemicals being dropped in your eyes...?)}
• Metal snips.
• Jubilee clips.
• Screwdriver (flat-head, to match the jubilee clips).
• Assorted pliers, spanners and thumpy things.
• Exhaust repair paste (available from any car spares store).
• An empty tin can.

You should also wear appropriate clothing - spare a thought for whoever does the laundry in your home, and be aware that you could quite easily get un-removable gloop on your clothes. An old hat might help as well.

Comments

[Yerboogieman]

We used to use a beans can like this for melting down pop cans while camping. It would stay red hot for about 2 hours or sometimes more before it finally broke. Since I have an axhaust leak, I will have to try this. Thanks Kiteman.

[latemtech]

you could have just cut off the flange, clean the area, and put an adapter over it and use muffler clamps. $10 at autozone.

[Kiteman]

...plus the cost of the tools to do the cutting ;-) (I did say it was a bodge-job. I don't even have the car any more, I sold it for spares.)

[starpenchal]

hey man, I also did the same today, but around the pipe still leaking, so i just put some addhesive materil, let me see what will happened. This so much useful. Thanks a lot, i just spend 6 $ for this process. Thanks man

[emuman4evr]

Would PVC pipe work?

[vanmankline]

I wouldn't use pvc, but I have used 2 inch galvanized steel pipe (bit heavy, but did the job). I also suggest coating seams with some high temp gasket maker (I used some wood burning oven sealant that was laying around) if you need to go through emissions testing.

[Babyshoes]

No, not unless you found some incredible PVC that could withstand temperatures of over 400 deg.C... Exhausts can get very hot, especially near the engine!

[JerryMopar]

probably would work really near the end of the tailpipe, no closer though, Burning PVC dosnt give the healthiest fumes.

[see-saw]

As compared with nice healthy exhaust fumes :-) hehe

[The Dark Ninja]

I was wondering the same thing. Could regular (or even special plumbing) PVC be used after the muffler instead of steel pipe? Not sure how hot the exhaust gets that far away from the engine.

[puffyfluff]

Nice. I like the intro: "The old clunker's exhaust was blowing a bit, so I sealed it. Then it fell off."

[ermockler]

I used to use furnace cement, which hardens with heat. A dedicated glove for shmearing while the car idles. you can also use window screen to wrap the muffler for strength. I have done a lot of this (and don't miss it), it doesn't last very long, you will probably only get 2-3weeks out of the repair. The cement cracks when you hit a bump.

[Sunny124613]

WOW your on a roll with instructable making!!

[Babyshoes]

Nicely done for a bodge job! Just a couple of points I would like to add: 1) When you say to move your hand along the pipe to feel for leaks, remember that it will get HOT, so be very careful. You can also listen if you can get far enough underneath to move along the pipe. 2) Never use exhaust paste upstream of the catalytic converter - if any breaks off inside the pipe it will smash up the blocks inside the cat which could stop your car from working, especially if it has a Lambda sensor. 3) You could have put exhaust paste around the 'male' section of the tin before putting it inside the pipe to make a better seal. Only put it on the outside of the 'male' pipe though, so that any excess paste gets pushed out not inside, where it can cause problems - see above. Oh, and as for the comment asking about rust-free exhausts, they are available but being made of stainless steel cost a lot! Also, the high temp paint wouldn't work terribly well to stop rust, as exhausts rust from the inside first. Did you know that a litre of petrol produces nearly a litre of water when it is burned (plus various nasties that cause pollution)? Most of that enters the atmosphere as steam, but when the car is cold it collects in the exhaust, which is why the back box tends to rust first, as it is furthest from the heat of the engine. The only way to stop exhausts rusting using paint would be to dip them in it, which would cost more and probably cause other issues!

[Kiteman]

1. Ah, good point - I will edit that.

2. I didn't know that, thanks for the info (it's not mentioned on the tub of paste)

3. I thought of that, but decided that I didn't want to risk restricting the gas-flow any more than I really had to, since the back-pressure can have a big effect on the engine.

[Babyshoes]

2. It probably wouldn't be mentioned on the paste as it is designed for mechanics who SHOULD know these things, but often don't! 3.Fair point, I see why you didn't, but if you used a thin layer and had excess squeeze out I doubt it would make much of a difference to the back pressure. Better safe than sorry though, I guess, especially with an old engine. Also, depending on the brand of exhaust paste you use, gloves may be a very important safety device! Some of them are quite caustic.

[Lithium Rain]

Haha! That's so ghetto! Also, yay Kitewife!

[Kiteman]

Hah, that was her sole contribution to the affair.

[timheppner]

Just a FYI, I did something similar to an old car of mine, I used a tin can and clamps to fix a hole in the exhaust. It lasted for all of a couple of months, and the tin can, being a thinner metal than the exhaust pipe, broke. I don't think that tin cans are meant to handle the heat of your car's exhaust.

[Kiteman]

I think it's probably the lack of rust-proofing... A couple of months is all I need from this fix - I start shopping for a "new" car at the end of October, and this thing is worth less than a hundred pounds (unless I trade in for a brand new car, which I'm not going to do).

[thematthatter]

Is this your famous car that gets like 60 "kilometers to a liter" (ha ha) you could have cut the whole section off and left it running a straight pipe, make your car sound like a teenager drives it .

[Kiteman]

The section I repaired is just pipe, and was before the silencer - if I lopped off the silencer I would have had the car impounded for breaking noise regulations (two, if I'd driven it at night). This old clunker gets around 40mpg, mainly due to being old and spending most of its driving time in queues.

[PKM]

Kilometres to a litre beat, I don't know, stadia to the firkin or furlongs to the bushel or whatever the Imperial measurements are. Ells per dram? Chains per cupful? OK, I'll stop now.
_{Maybe football pitches per tablespoon...}

Also, isn't there some sort of high temperature paint suitable for use on exhausts? They seem to be such a common source of extensive rust woes that you would have thought some enterprising soul would have come up with "exhaust-rust-b-gone". That said, it would probably just rust from the inside...

[Josho]

Those ramps scare me. They're rusty and like my dads old pair. My brother drove his Polo Coupe up on them and they fell through. Thank goodness we weren't underneath them. I totally agree with the jack bit, my grandad was changing his wheel when the jack slipped and he had his legs uder it. Luckilly they were clear of the wheel and his legs were under teh bumper, so it merely touched his legs. NEVER EVER EVER go under a car with just a jack. If your car wo't go on a ramp, do what we do with my brothers new car, jack it up and put the ramps underneath the axle.

[Kiteman]

The ramps are stronger than they look - it's all surface rust. I prefer ramps to axle stands, because they're wider and more stable, but some jobs need a wheel off...