Will this replacement flex pipe damage the exhaust manifold?


#1

The flex pipe on my '94 Ford Escort came detached due to rust. I bought a replacement flex pipe and had a welder at a custom exhaust shop weld it in place. Comparing them side-by-side under the vehicle, I noticed that the original section of flex pipe was somewhat longer, and looked much more heavy duty than the one I replaced it with.



Basically, the replacement looks kind of wimpy compared to the original, even though they both look basically the same?they are both the kind with the metal mesh around it.



Even though I had some doubts, I went ahead and had the exhaust guy/welder replace it anyway because he said the replacement part would be ok (not that that means anything, of course) and I was just REALLY tired of sounding like a pack of Harleys driving down quiet residential streets in my little Escort.



I love driving a quiet car again, but should I get a flex pipe on there that matches the original more closely?


#2

I forgot to add, thanks in advance for your replies!


#3

If the replacement is shorter and thinner gauge, yes, it probably won’t last as long as the original. But even if it only lasts half as long, that puts you out to 2015. Maybe you’ll be able to buy another car by then!


#4

Ha, you’re right about that!

Just to clarify, I’m not at all concerned how long the job will last, my only concern is not to cause damage elsewhere (like at the manifold) due to lack of flexibility.


#5

It’s a flex pipe. It will flex. Since, it’s most likely made of lesser quality alloy steel than the original (and probably made in China) it’ll last a much shorter time than the original. It won’t have any negative impact on the rest of the engine.


#6
 The flex pipe flexes at the other end . . .where it attached to the rest of the exhaust, not at the manifold end.  Not a problem, just replaced one myself on my Honda.  Curiously though . . . my replacement seemed a lot heavier than the original.  Good luck!  Rocketman

#7

It’s impossible to tell without looking.

If the original was longer, the replacement may not provide sufficient flex and strain on things like motor mounts or even the header pipe may result. If the inside diameter is smaller the new pipe may have insufficient CFM (cubic foot per minute) capacity and provide too much back pressure.

I emphasize that it’s impossible to tell from here. But if the future I’d suggest getting only “direct fit” replacement parts.


#8

Thank you for the info (even though that’s not the answer I wanted to hear!)

Just from having eyeballed them, the replacement did seem somewhat smaller in diameter, so I hope whatever extra back pressure this creates won’t be damaging.

In light of what you’ve said, I suppose I’ll consider this just a temporary fix until I can get the actual replacement part installed.

Side note: I know it’s an old cheap car, but I’m really fond of it and I’d like to see it go as long as it can.


#9

I would like to add that you shouldn’t worry about the flex pipe damaging the exhaust manifold. Usually it takes a blocked catalytic converter to do that. It’s also a 94 Escort and nobody worries about replacing those. They are easy to replace.


#10

I second what PDV said - just motor on with the flex pipe you put in and don’t worry about it! This isn’t a Ferrari; I’m sure it will not be affected by a 1% difference in size, etc. I personally would not spend any more money on that part of the car. PDV would probably counsel you not spend any more money on the car, period. He doesn’t like old cars. :slight_smile: