Exhaust Flex Pipe Questions

[joshjani]

My latest mechanic pointed out that the flexible braided pipe on my SW2 is worn out- I did notice it, but haven't done anything about it yet.

He tells me that the flex pipe cannot be removed from the downpipe, that I'd have to replace both. OK with me, if that's true. He's putting on parts that I buy, and I'd like to know what to buy.

So, is it common to have to replace both that downpipe and any flexible pipe? They ARE seperate parts, right? I suspect he says he can't change just the flex pipe because it's so rusted and corroded to the pipe.

Neither my Chilton book nor my Haynes book depict any type of flex pipe being used in the exhaust system. In their drawings, the header looks to be attached to another rigid pipe- is this the downpipe? I just can't figure it our from these scant drawings!

Thanks for any assistance.
JC

[LowSC2]

Do you have any pictures of the flex pipe? Because unless it's leaking exhaust I woudlnt worry about it.

[amazinghl]

You replace it by cutting the old one off and welding a new one on.

[93 saturn sl2]

when i got my exhaust done they told me that my flexpipe was bad so i came in a couple days later and got it replaced looks like they just cut off the old one and weld on the new one to the cat and downpipe.

[joshjani]

Originally Posted by LowSC2

Do you have any pictures of the flex pipe? Because unless it's leaking exhaust I woudlnt worry about it.

Here's A pic- looks bad at the ends, but I don't smell any exhaust.

Mechanic said it sounds like it's bad because the engine is noisy- but I also have the bottom of my airbox cut out, and it growls a bit.

So whaddya think of the condition of that pipe? Can I just wrap the thing with that stupid muffler tape and hold off for a while?

JC

[Bill Murray]

IMHO it doesn't look bad......close inspection should reveal any leakage

[Low Saturn]

If it looks like that on the opposite side as well, then it doesnt look like there is anything wrong with it. I've seen a LOT worse. If it was leaking there would be black soot from the spots were it leaks.

[joshjani]

Thanks all-

I'm gonna wait a while, then. I go for inspection in August. I'll see if she passes!
JC

[irish56]

Go to www.napaonline.com and check out part #52165 - it's the pipe from the exhaust manifold to the catalytic converter (does not include the converter). I plan to install it on the '95 SL1 sometime in the next month because the original pipe is leaking fumes pretty bad and is noisy to boot.

I will post pics when I do the job. I am a little concerned about how to join the new pipe to the cat because it looks like there's a welded joint right where I want to cut/splice the pipe. It would be much easier to replace the cat too (#15842) but that's a lot of money.

[joshjani]

Yep- that's it! I svaed the link, but I think I'm gonna wait a bit anyway. Is $87.99 a good price for that? Seems OK to me, but I don't know, really.

[irish56]

$88 is a little high, I think, but it's WAY cheaper than the Saturn dealer or Midas. Advance Auto's web site lists the same part number for something like $63, but has no picture, so I can't be sure it's the same part unless/until I stop by a store.

[saturnhacker]

the outer braided pipe is not gas tight. its really for protection and strength of the pipe assembly. the exhaust gas is actually carried by a double wall corrugated pipe inside the braided pipe. i would not worry about it unless its obviously broken/leaking.

[katarn444]

I have a question about the braided pipe, What is it for? My only guess would be for vibration dampening. I am thinking about replacing mine with a straight pipe. The entire system is isolated from the car with the rubber hangers. My only concern is for the exhaust manifold, some extra forces might be applied to it.

The reason I ask is because my cat is dead, rattling pretty badly, and my 93 has the downpipe, flex pipe and cat all connected. I was afriad that when I take it off to fix the cat the flexpipe would break. I looks like joshjani's picture. So I was going to pull the whole thing off, cut off the cat and weld it back on, and if the flex pipe break then just replace it with a straight pipe.

Any thoughts or suggestions?
Thanks
katarn

[kmix99]

The braiding acts like a heat shield. They have a tendency to come loose because the tack welding that holds it to the ends of the flex pipe rusts easily. If this is the case, you can purchase two large ( preferably stainless, from Lowes etc..) hose clamps and clamp it to the flex pipe, one on each end where the weld rusted.

I've seen others cut it off completely.

[saturnhacker]

Originally Posted by katarn444

I have a question about the braided pipe, What is it for? My only guess would be for vibration dampening. I am thinking about replacing mine with a straight pipe. The entire system is isolated from the car with the rubber hangers. My only concern is for the exhaust manifold, some extra forces might be applied to it.

The reason I ask is because my cat is dead, rattling pretty badly, and my 93 has the downpipe, flex pipe and cat all connected. I was afriad that when I take it off to fix the cat the flexpipe would break. I looks like joshjani's picture. So I was going to pull the whole thing off, cut off the cat and weld it back on, and if the flex pipe break then just replace it with a straight pipe.

Any thoughts or suggestions?
Thanks
katarn

i wouldnt remove the flex portion. when the engine torques (twists) its going to put constant stress on the pipe. if the flex part is not obviously damaged/leaking dont mess with it imo. the outer mesh might be loose/scraped but the inner pipes should be good, they dont fail often even on cars with miles.

[sl_don]

Originally Posted by saturnhacker

i wouldnt remove the flex portion. when the engine torques (twists) its going to put constant stress on the pipe. if the flex part is not obviously damaged/leaking dont mess with it imo. the outer mesh might be loose/scraped but the inner pipes should be good, they dont fail often even on cars with miles.

the engine torquing is the only reason i see for having the flex pipe. but i have had other 4cyl fwd cars where their was no flex pipe and no problems so it it would be nice to know a good reason for it. if a good reason dose not exist i will eliminate it when it gose bad.

MK2 Jetta had no flex pipe
sunbird 2.0 OHC had no flex pipe

[ssicarman]

Unless you have an actual exhaust leak from the flex pipe there is no reason to change it. The wire mesh is there to protect and give strength to the metal flex joints under the mesh. It would need to be in very poor shape to replace the flex pipe and even then I wouldn't do it until it was leaking exhaust. At that point is is a safety issue.

[katarn444]

One other note is that many other cars which I would consider to have engine that torque in the engine bay a lot more then the 1.9 do not have flex pipes, ie my jeep cherokee. The only real difference is the inline 6 4.0L is of coarse rear wheel drive so the engine movement is in a different direction, side to side versus front to back.

I think I will take it off if the flexpipe beaks I will put a straight pipe on and see what happens. I still have not decided weather or not to get a new cat or just let the crumbled insides pour out. I do not like poluting any more then I have to but I also do not like spending $80 or so on a cat, plus I need a new muffler.

I will give an update if I do indeed replace the flex with a straight peice.

katarn

[ProDarwin]

http://www.jcwhitney.com/webapp/wcs/...atalogId=10101

Use one of these.