Really loud exhaust only on cold startup

Yesterday afternoon I got home, parked my car and it was running silently. I went out that night get in it and start it up and it was painfully loud. As the motor/exhaust warmed up, it became quiet again.

Same thing this morning. Started the car and it was like it had no exhaust. Started driving to work, and no more than 2 minutes later, it was silent and stayed silent.

What the shit is causing that? Loose bolts on the header? Car is a '96 Subaru Outback with a 2.2L H-4 motor.

I’ve heard of cracked exhaust manifolds sealing themselves as they heat up…never saw it before though. Might be worth checking.

have you looked yet to see??? if anythign loosey-goosey

it is trying to convert itself to a rally car, you know you want to let it do so… :slight_smile:

Dunno, brent_strongs idea makes sense, all though i’ve never heard of it happening.

No time. It was late last night, and I woke up this morning at 7:25 and needed to leave by 7:35. Haha. I made it in on time.

I’ll be under it tonite as I needed to do the brakes anyways. I was just wonderinf anyone had experienced this before and if there was anything in particular to look for.

Is the entire exhaust setup stock?

Stock and essentially rustfree.

where is the sound coming from? engine bay? underneath? rear?

is the idle at any higher of RPMS when cold?

[quote=“Jagermeister,post:8,topic:36240"”]

where is the sound coming from? engine bay? underneath? rear?

[/quote]

Sounds to be underfoot more or less. I can’t tell if it’s drivers side bank or passangers side.

under your feet is what? downpipe area?

[quote=“K Cuv,post:9,topic:36240"”]

is the idle at any higher of RPMS when cold?

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Nope. Regular cold idle speed, which is around 1k or so as usual. It goes down to 600 when warm, but it’s always done that.

[quote=“K Cuv,post:11,topic:36240"”]

under your feet is what? downpipe area?

[/quote]

Basically yes.

Imagine a V8. The exhaust setup is similar, but it’s only half the cylinders.

So I foudn the problem.

It’s about midway underneath the car, there is a point just after the cat. where it bolts together with the rest of the exhause, cat-back style.

The flange rotted and the flange itself broke apart. The pipe itself is in great condition.

It seems as if the heat from the cat. is almost more or less welding that pipe back together after a short bit of driving, as the pipe kind of sits inside the other part.

Now I have to see what my options for repair are. I am kind of wondering if an exhaust shop would cut out the flange, and insert a solid section. But one concern of mine with doing that is there are these intersting spring type things on the flange bolts, and there is no flex-pipe anywhere in the system.

[quote=“Bigairskier1580,post:14,topic:36240"”]

there are these intersting spring type things on the flange bolts, and there is no flex-pipe anywhere in the system.

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that is the only flex joint in the system, I wouldn’t replace that with a solid piece.

Flange is done for. it rotted off around the holes completely. Only the cat side that is. The rearwards side is completely fine. All the steel is solid as well aside from the little section on the flange that rotted off.

I’m really hoping there’s some way to save it, because that little section of piping if I buy it online for the best price I’ve found is $300 for the part itself, all because of the cat.

pic? What size pipe?

No pic, I didn’t even think of that. It’s raining now, maybe later I’ll snap one.

The pipe size is rather small. About 2" in outer diameter.

I’m hoping a new flange can be welded on or something. Can anyone recommend a good exhaust/welding shop that could take a look at it?

You can look at it without even jacking the car up because it’s a Outback with the raised suspension and hoigher ground clearance.

take it to a muffler shop, a repair like that is usually pretty cheap.

new flanges can usually be welded on no problem. i’ve done it quite a few times.