Over the past couple of days I have noticed a grumbling noice coming from just behind the firewall and reached its loudest yesterday. After mild surgery, I found the exhaust manifold cracked right at a union mark on the resonator. Fellow MINIacs please chime in with suggestions to help get my MINI happy again. I really really dont want to buy a WHOLE new exhaust manifold!!!

 

With so many people replacing exhausts, I would try and find a good used one here on NAM in the wanted section. I have a full exhaust in my buddies attic, but I have a mini with stock exhaust on it so it is a keeper for me.

 

If you have under 100,000 miles, it may be covered under the emissions warranty - call your dealer.

 

It might be possible to have it "Brazed" up.
Costs would probally be more than a used header.

 

I was hoping for this too, but 5yrs or 50K miles. Which ever comes first. And I never bought the extended warranty.

 

Trying this next. How expensive could this be? When I called the dealer to check on the warranty (strike out), I priced a new manifold too. $1086.00 I might as well buy the Milltek performance header for that price. lol. Would Brazing hold?

 

Anybody heard about the Megan header where you cut the empty out and weld the OEM cat onto it. Any success stories?

 

Since the exhaust manifold is integral with the pre-cat and the cat, it should
be covered by the federal emmissions warranty which is 8 years/80,000 miles.

http://www.epa.gov/otaq/consumer/warr95fs.txt

They might say this doesn't apply because the converter itself didn't fail, but
the pic looks like the crack is right on the end of the pre-cat which should qualify.

 

Good call, emissions equipment has a longer waranty...start there...

 

Well, no luck yet.
I thought about the 8/80 but quickly realized my MINI is at 97k.
I tried 2 different welding companies today which they said it couldnt be done.
So I guess I may be moving on to the next step. Maybe the Megan headers which Waylan carries and cut the flange off and weld it to my oem cat. Kinda at a stalemate right now. If I should wait and look around or dive in on the Megan headers.

 

Spening money sucks, but if you get a header, and a nice muffler, a good shop can custom make the piping and you can get a full exhaust. It is always nice to upgrade rather than replace parts as they break. After the wallet hurt, there isn't much of a downside.

 

Has anybody heard of Exhaust Distribution? They have an operational header with cat but cant find any info if they are a reliable source. 420 with shipping. found it on ebay and looked up company name.
- I already have a Magnaflow catback system -

 

Have a shop cut the precat out and just weld a tube in there, shouldn't cost much. As long as you keep the main cat you shouldn't throw a CEL.

Edit: That would be about 15min to cut and fit, 20 min to fit it on the MINI (figure 2 person job that actually takes 10min) and then 15-20 min to clean and TIG it if I am working really, really fast and things are going smooth.

 

the same thing happened to me this past week. I was driving into work and the weld broke in the same spot. i took off the manifold and then cut the sleeve off over the precat. I then ground the weld a little and welded it back together at work. the weld came out good and the car sounds like it did before the pipe broke. i was thinking about putting an aftermarket header on the car but the money is tight at the moment.

 

My R53 just had this same thing happen (135,000 miles).

R53Fort, or anyone else that welded it, any long term data on if it lasted? I have both MIG and Oxy Actylene. I can't make fast good pretty welds, but I can make strong ugly welds slowly . It didn't look easy, but it looked doable.

Just looking for any data points on if it's worth trying to fix while I go try and scare up part prices.

 

Uh, and what's up with all the sub $200 stainless R53 manifolds all over ebay? Seems too cheap to be true. Or is this just a case where supply is really high and demand is low and everyone is dumping inventory?

I'm guessing they don't have a catalytic converter. I'm not in CA, but I'd really rather not run a car without a cat, it's just rude. And I'm guessing the ECU would also throw codes right and left trying to fix what the O2 sensors are seeing, and I'd rather not mess with the tune either.

 

You are correct about too cheap to be true. If you have the ability to weld and the skill, I would just do it. My exhaust manifold broke in two at the Cat. I purchased a used one here on NAM for $150. If I had the tools and the skill I would have just welded the pieces. On a side note: If you've been putting off a leaky Oil Filter gasket/Oil Cooler O-rings, once you take the exhaust manifold off , it get no easier to replace those parts than at that time.

 

The repair actually went really well.

The first thing I should have done (but didn't) was go under the car and scribe some really good witness mark with everything still bolted together, so I could tell how the two parts should be rotated relative to each other when welding them back together. I figured it out based on trying to match the two broken pieces back together like a jigsaw puzzle, and it worked fine, but it was a pretty risky gamble. It was a really clean break, so it would have been easy to have wrong match that looked right, then I would have had to cut it all and reweld after finding out it wouldn't fit right.

The bolts were of course rusted to solid masses, so they had to be cut. I cut them flush with an oscillating saw with a tungsten carbide blade, which released the collector side. But the remainder of the bolt was still good and stuck in the other side (which I left on the car while attacking). Those studs were pressed in tight even before they rust welded themselves in. I drilled them out with progressively larger drill bits, and when they were big enough to relieve the internal tension, I was able to punch them clear using a punch and hammer. Took forever though, so file this approach under "affordable and effective, but slow and annoying?. I probably should have just fired up the oxy acytylene torch and melted them off and out, but I try and follow the "first do no harm" philosophy of mechanics, and I do a lot of harm when the cutting torch comes out.

It would be worth trying an air hammer with chisel tip, if anyone has tried that and if it worked, let me know. That oscillating tool with the carbide blade solves a lot of the same problems an air chisel may solve, but is probably slower and more expensive ($8 per blade or so, and a blade may get trashed after two or three bolts).

Anyway, then it was time to pull the header and downpipe assembly. I pulled the bolts holding the header in from the top, again mildly annoying but not hard to get too, and they all came out nicely without threat of shearing (a big relief, that would be a massive PITA to extract with the engine in place). Then I could barely wriggle the down pipe out the bottom of the car (it looks like it won't fit, but it eventually did with only a little bit of prying and forcing.

I left the O2 sensors in place and just unplugged the wiring. Maybe they would have come out easy on the Mini, but they never have on any other car I've owned.

So bringing the downpipe over the the bench, I tried flux core mig welding it. It sort of was working, but it was also sort of a mess. I'm not great with a MIG, but I'm not terrible, so I think the real problem is that flux core MIG just sucks, and my cheap MIG unit has irrational feed speed behavior (literally imperceptible adjustments to that feed speed **** go from "too slow" to "too fast). Gas shielded MIG, and a sanely designed feed speed ****, and MIG would probably work fine.

In my case, I also fortunately have Oxy Actylene (the reason I don't bother to upgrade the MIG, the Oxy just works SO well for me). I broke all that out with a small tip, and it welded up beautifully and completely under control. The other advantage of Oxy Actylene is that you don't have to clean the surface as well, the heat pretty much burns off all the crap while things are getting hot enough to weld. And given the shroud over that broken joint, it is really hard to get in there for a proper cleaning to use MIG (or presumably TIG).

I didn't worry too much about accidentally melting the edge of the shroud thingy, so a few bits of the shroud became filler rod. It was easy to get in there with a small torch, but I did have to stop and preposition it pretty often to get clear access and keep gravity pulling the molten steel the direction I wanted it going.

From there I just had to add the one or two obligatory arm tattoos by not waiting for it to cool enough and bumping it, then took it back out to the car and wriggled it up there and put it all back together. I had new gaskets for both ends of the header pipe on hand, and used them, but the old gaskets came out and looked like they probably would have worked fine resused (they were good metal gaskets with no sealer). I installed the new gaskets dry (no RTV or anything). The header bolts looked in really good shape for a 130k mile car and for being header bolts, that's usually a really bad environment for a bolt. I reused them.

I didn't see anything on the header bolts going into the head, I put anti-sieze back on them. And I grabbed a few spare bolts off the bench junk coffee can and used those in place of the studs that I drilled out that joined the collector / cat to the rest of the exhaust. I could have welded the bolts in as captive studs, but I chose to just use two wrenches, which was easy enough.

It's been a couple weeks now, and the car has been driven all over, and it is holding great so far. I used fairly soft ductle steel filler (really cheap harbor freight steel wire actually, because my stash of proper filler rod was used up). I may regret that, as it will rust a lot faster than the semi-stainless that the header is made out of. Or it may be a case of "better lucky than smart" as the thick weld won't rust fast anyway given its half my soft steel and half the original stainless, and given it broke before, less brittle is perhaps more important than less rusty.

We will see how it lasts, but I'm very happy with how well it went. Most of the time was spent cutting the old bolts off, I could have found a lot of faster ways to do that, but those also may have created more and even worse problems.

If anyone is passing through the Cincinnati / Dayton area and has a mini with the same problem, drop by with the down pipe removed and marked for how the two pieces should go together, and I'll weld it up for you. I'm always looking for some excuse to weld.

If you don't have a welder, and won't be welding that often, consider getting an oxy-actylene rig over a flux core MIG rig. You can do a lot more with it. TIG would be cheaper to use, but is really expensive to buy. I've not tried gas shielded solid core MIG much, so I don't really have an opinion on if it is a good middle ground or not.



(Still glowing, and waiting for me to sear an elbow on it, which of course I somehow did to *both* elbows before I was done)

 

Glad you were able to save it.

 

Nice work reepicheep, mine just separated today. I can't weld and I'm unfortunately not near you. I'm headed to a muffler shop tomorrow to see if they'll weld it for me. Do you think it could be welded on the car? or does the manifold have to come off?

 

They will absolutely have to take off the header from the engine. Probably an easy job for them, they are used to it, and the mini is a lot easier than most cars to get at those header bolts. They can probably reuse the gaskets fine.

They will likely have to cut the bolts at the other end, past the catalytic converter. If they do it carefully, they should be able to keep everything but just use three new bolts with nuts.