Exhaust Question

GKLCPA · Post by **GKLCPA** » Dec 10, 2012 8:41 PM

Put a new performance chip in my eta today and while driving around enjoying my third and fourth gears, my 02 sensor pops out of the downpipe. This is about the 3rd time it's done that in as many weeks. The problem is that hole the sensor fits in is not catching the sensor threads, so the sensor fits in there snug rather than tight like it's supposed to and once the exhaust gets hot, it pops out. Looks like the previous owner stripped the thread in the down pipe at some point. I'm not certain if a new thread can be tapped or not as the hole is slightly larger than what it should be.

Is my best option here to just procure the portion of the downpipe running between the engine and the cat and just have it welded in?

alijonny · Post by **alijonny** » Dec 10, 2012 9:02 PM

Can't you just go to the local exhaust shop and have the old bung cut out and a new one welded in? Shouldn't be too expensive... A new bung is like $5

GKLCPA · Post by **GKLCPA** » Dec 10, 2012 9:18 PM

alijonny wrote:Can't you just go to the local exhaust shop and have the old bung cut out and a new one welded in? Shouldn't be too expensive... A new bung is like $5

Ok. Wasn't sure if it could just be a generic part or not. Let me check that out with my shop. Thanks !

ahab · Post by **ahab** » Dec 10, 2012 10:07 PM

I bought a bung at NAPA in Allentown for $3. I can't remember the size, 1.25X18 I think.

GKLCPA · Post by **GKLCPA** » Dec 10, 2012 10:22 PM

Simple, cheap and easy-----all of which I can deal with.

I'll pick up a new bung somewhere tomorrow.

GKLCPA · Post by **GKLCPA** » Dec 12, 2012 4:14 PM

Took the car to my exhaust shop today and just looking at the location of the bung (I have an eta), there's not enough room/access to do any welding unless the down pipe is dropped. If this was my 535i, this wouldn't be a biggie, but I don't see how this is a easy weld job. We got the O2 back in, but I suspect it's gonna pop out again. Any suggestions here?

Rich Euro M5 · Post by **Rich Euro M5** » Dec 12, 2012 5:58 PM

GKLCPA wrote:Took the car to my exhaust shop today and just looking at the location of the bung (I have an eta), there's not enough room/access to do any welding unless the down pipe is dropped. If this was my 535i, this wouldn't be a biggie, but I don't see how this is a easy weld job. We got the O2 back in, but I suspect it's gonna pop out again. Any suggestions here?

JB Weld

demetk · Post by **demetk** » Dec 12, 2012 6:05 PM

GKLCPA wrote:Took the car to my exhaust shop today and just looking at the location of the bung (I have an eta), there's not enough room/access to do any welding unless the down pipe is dropped. If this was my 535i, this wouldn't be a biggie, but I don't see how this is a easy weld job. We got the O2 back in, but I suspect it's gonna pop out again. Any suggestions here?

Can't you weld the old one shut and relocate the new one?

pleasefixitup · Post by **pleasefixitup** » Dec 12, 2012 6:14 PM

GKLCPA wrote:Took the car to my exhaust shop today and just looking at the location of the bung (I have an eta), there's not enough room/access to do any welding unless the down pipe is dropped. If this was my 535i, this wouldn't be a biggie, but I don't see how this is a easy weld job. We got the O2 back in, but I suspect it's gonna pop out again. Any suggestions here?

Guessing it's your 528e. It can be done. I have the downpipes--I'll post a picture in a second. But I can see how the exhaust shop would "stray" away from doing the work.

I think the last picture shows it the best--Hopefully you're talking about a 528e. I personally don't like the design of the downpipes but it's nice that the 02 sensor takes a reading from all 6 cylinders and not just 3.

You could always be nuts and weld it in (not saying you should or that I would!)

demetk · Post by **demetk** » Dec 12, 2012 6:30 PM

Never mind my question. I see the problem now.

GKLCPA · Post by **GKLCPA** » Dec 12, 2012 6:47 PM

pleasefixitup wrote:
GKLCPA wrote:Took the car to my exhaust shop today and just looking at the location of the bung (I have an eta), there's not enough room/access to do any welding unless the down pipe is dropped. If this was my 535i, this wouldn't be a biggie, but I don't see how this is a easy weld job. We got the O2 back in, but I suspect it's gonna pop out again. Any suggestions here?
Guessing it's your 528e. It can be done. I have the downpipes--I'll post a picture in a second. But I can see how the exhaust shop would "stray" away from doing the work.

I think the last picture shows it the best--Hopefully you're talking about a 528e. I personally don't like the design of the downpipes but it's nice that the 02 sensor takes a reading from all 6 cylinders and not just 3.

You could always be nuts and weld it in (not saying you should or that I would!)

Yep, this is what we were talking about (and what I was wondering before I got there). He's afraid of stripping the studs and making this an even bigger job.

GKLCPA · Post by **GKLCPA** » Dec 12, 2012 6:49 PM

Rich Euro M5 wrote:
GKLCPA wrote:Took the car to my exhaust shop today and just looking at the location of the bung (I have an eta), there's not enough room/access to do any welding unless the down pipe is dropped. If this was my 535i, this wouldn't be a biggie, but I don't see how this is a easy weld job. We got the O2 back in, but I suspect it's gonna pop out again. Any suggestions here?
JB Weld

That might work until I have to replace it?

pleasefixitup · Post by **pleasefixitup** » Dec 12, 2012 6:49 PM

manifold studs ? or downpipe studs?

GKLCPA · Post by **GKLCPA** » Dec 12, 2012 6:51 PM

pleasefixitup wrote:manifold studs ? or downpipe studs?

I'm guessing the one's on the downpipe

GKLCPA · Post by **GKLCPA** » Dec 12, 2012 6:52 PM

You don't have to deal with the manifold studs anyway right?

pleasefixitup · Post by **pleasefixitup** » Dec 12, 2012 6:57 PM

GKLCPA wrote:You don't have to deal with the manifold studs anyway right?

no you don't. Those are simple.

The problem is two of the 6 bolts are unaccessable from beneath with sockets / long extensions.

you need muscle and a open end box wrench, I think 13 mm.

look closely for the 2 nuts that aren't removed at the flange. One for each downpipe.

Those are the two you will have trouble with (maybe my 88 seta was different) but I couldn't reach those. Maybe I needed a different combination of pivoting sockets / extensions...but I got annoyed and chopped it off because I my dad had 3 welders so I can just weld later, plus I needed m30b34 downpipes for my new motor--so chopping had to happen anyway.

GKLCPA · Post by **GKLCPA** » Dec 12, 2012 6:59 PM

pleasefixitup wrote:
GKLCPA wrote:You don't have to deal with the manifold studs anyway right?
no you don't. Those are simple.

The problem is two of the 6 bolts are unaccessable from beneath with sockets / long extensions.

you need muscle and a open end box wrench, I think 13 mm.

Are you going at those two from the top?

GKLCPA · Post by **GKLCPA** » Dec 12, 2012 7:01 PM

never mind---you answered

pleasefixitup · Post by **pleasefixitup** » Dec 12, 2012 7:06 PM

whether you precisely cut and weld a new bung in, or add a new set of downpipes with an intact o2 sensor bung--you've still got a "bit" of fabrication on your hands.

for me--fun. get some thick gloves and a long sleeve shirt or two!

GKLCPA · Post by **GKLCPA** » Dec 12, 2012 7:12 PM

pleasefixitup wrote:whether you precisely cut and weld a new bung in, or add a new set of downpipes with an intact o2 sensor bung--you've still got a "bit" of fabrication on your hands.

for me--fun. get some thick gloves and a long sleeve shirt or two!

Yep..that would appear to be so.

I'll be outsourcing this one!

pleasefixitup · Post by **pleasefixitup** » Dec 12, 2012 7:47 PM

GKLCPA wrote:
pleasefixitup wrote:whether you precisely cut and weld a new bung in, or add a new set of downpipes with an intact o2 sensor bung--you've still got a "bit" of fabrication on your hands.

for me--fun. get some thick gloves and a long sleeve shirt or two!
Yep..that would appear to be so.

I'll be outsourcing this one!

not a bad idea, smaller exhaust shops can get a job like this done cheap.

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Exhaust Question

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