Exhaust repair ideas

I have a 97 318i DD/winter beater that has sprung a very annoying exhaust leak, looking for some budget minded repair options. The exhaust header flange bolts are pretty badly corroded which has allowed the flange to loosen up and leak. I was thinking I could cut the bolts off and drill/press out the studs but there just isn't enough room. The proper repair is going to involve removing the header from the car and pressing out the studs on a shop press. I already know I'll encounter a multitude of other unnecessary problems typical with disassembling any 15 year old northeast car and I just don't have the motivation. If I bring it to someone, I can see at least a few hours worth of work and it's just not worth sinking that kind of money into this car. I can deal with the raspy exhaust note but the exhaust is leaking up into the cabin; making the lady friend nauseous probably isn't in my best interest. Any ideas?

Said offending vehicle, shameless photo whoring

Slap some of that putty exhaust sealant around there. It will stop the problem, but will end your chance of any proper repair.

N Sperlo wrote: Slap some of that putty exhaust sealant around there. It will stop the problem, but will end your chance of any proper repair.

Where can I buy that and why will end end any chance of a proper repair?

Baling wire?

I'd snap/cut the studs off, then drill them out and put new studs in and get on with life. Pick up a new flange gasket/metal O-ring while you're at it.

Another thought is to find a couple of spring washers to fit over the studs/nuts and hold them in place with some slotted fender washers, but I don't think there is enough room.

Get some epoxy ether high temperature liquid 2 part epoxy, or High temperature solid epoxy (the stuff you have to knead together until it is a solid color.)

Before using it. Clean the area as thoroughly as possible. When you think you are done cleaning.... Spend 20 more minutes cleaning it. If you can get the area to bare metal (using any means necessary) do it.

After cleaning it. Apply the epoxy to the wound. Jam it as full as you can. Work it in there good. If you can jam a little more in go for it.

After packing it tight let it cure as per the manufacturers instructions. Don't start or move the car. If the car is on jack stands, leave it there until the curing process is fully over.

Finally look to see if any exhaust hangers have been damaged or become detached which may have caused the problem. If so repair or secure them so it doesn't happen again.

I did this 4 years ago in a similar climate to a lesser vehicle. The patch is still holding. Initially I skimped on the thorough cleaning of the area. It held up for a few days. After properly cleaning it, the repair still holds.

if they are screw in studs- and they likely are- then you need to break the nuts off, making sure to leave at least 1/2" of stud sticking out.. use a torch to heat up the flange around the stud as hot as you ca get it- where it just starts to glow orange would be perfect.- and use a pipe wrench (not a vise grip, channel lock, or anything that isn't a pipe wrench) with constant pressure to turn the studs out. it really isn't that hard to do, but you need a mapp or proper oxy acetylene torch to do it right.

if you only have access to a propane torch, then get the flange as hot as you can and spray some good penetrating oil on it- i like the foamy PB Blaster- and smack it with a hammer a few times to jar it enough to let the oil wick up into the threads.. repeat this a few times over a few days, then do like i said before with the pipe wrench.. it will probably come out.

Stargazer wrote:

N Sperlo wrote: Slap some of that putty exhaust sealant around there. It will stop the problem, but will end your chance of any proper repair.

Where can I buy that and why will end end any chance of a proper repair?

Any auto parts store. This E36 M3 can be ground off, I guess, but it's obviously not weldable. Your not going to grind it out of the groves you put it in.

I'd do what they suggest. Fix it right. Remove those suds. PB Blaster.

My Dad has a partner at work that specialized in this. He literally cuts the manifold off in five or six sections so that it can be removed without taking the studs with it. At that point he heats the studs to spin them out. Drilling out those holes and retapping, especially while on the car, can be downright nasty.

Google "clamp-a-stud". You would need to cut off the non-functioning part of the stud (basically "breaking" it), but otherwise this is designed for your situation. They look like this:

http://www.ebay.com/itm/Exhaust-Manifold-Stud-REPAIR-CLAMP-A-STUD-NO-RESERVE-/220930312483?nma=true&si=P9u9pIjGLvP9uUI6tdS8RVBSlCo%3D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

Available at just about any FLAPS for ~$25 retail and should get you by until you need to pull the manifold for some other reason.

now that is a nice looking winter beater. the sideskirts are not flapping that must mean the rockers are still there.

i get this repair done all the time at my local Midas shop for $50.00 to a $100.00 but i have a long relationship with them. i would go and talk to them its free and if you think about it if they will do for less than a $100.00 you will be ahead of the game. repairing exhaust is a nightmare now if you have access to a lift and the tools then go for it. but if you have to lay on your back and only have basic tools get a price from the local muffler shop

Snap the studs off and replace the gasket and use two I beam clamps.

Dwarf has the simplest/cheapest answer.

or a small pair of harbor freight vise grips. it works for quite a while....ask me how i know. lol.

I'd tack weld the two flanges together. You have a lot of meat there. If you ever want to get it apart, just slice the welds with a zip wheel on an angle grinder.

Wow tons of great ideas, thanks everyone. I knew I posted this question here for a reason. Leaning toward giving the i beam clamps/vice grips a shot and going from there if that doesn't work.

Tell me again why you are going direct to ghetto rather than just remove the nuts and put new ones on?Looks like there is thread under that nut

I work on a tonof brit-E36 M3 that has rust down to an art, and my steadfast belief is tha the best way to deal with broken bolts is to not break them in the first place. So , why are you not considering a torch and some penetrating fluid and a healthy application of patience?

There are even sockets made to grap rounded off nuts that might come in handy.

Last one I "fixed" I used two of these.

About $4 at the local hardware and about 15 minutes to install. They lasted over 50K miles, until the car went to the junk yard. The clamps are hanging above my bench now. Apparently they were better quality than the bolts they replaced.

European wrote: or a small pair of harbor freight vise grips. it works for quite a while....ask me how i know. lol.

Been there done that. I forgot that I had them installed when I sold the car. The new owner called asking if I wanted my vice grips back. At first I had no clue what he was talking about.

NOHOME wrote: Tell me again why you are going direct to ghetto rather than just remove the nuts and put new ones on?Looks like there is thread under that nut I work on a tonof brit-E36 M3 that has rust down to an art, and my steadfast belief is tha the best way to deal with broken bolts is to not break them in the first place. So , why are you not considering a torch and some penetrating fluid and a healthy application of patience? There are even sockets made to grap rounded off nuts that might come in handy.

there is no thread under those nuts any more.. they are one with the stud and the only way it is coming apart is to cut/break the studs and use some combination of fire, penetrating oil, finesse, and brute force to get the studs out.

If you go the route of removing the studs, they may be easier to remove if you can release some of the clamping force of the flange on the stud.

The easiest way is to make horizontal a cut into the flange from each side until it reaches the stud.

If the studs are pressed in, they will knock out with a hammer easily and can be replaced by through bolts with nuts. If they are threaded the release of tension in the hoop direction around the stud should help break the grip on the rust and with penetrating oil allow them to be removed easier.

novaderrik wrote:

NOHOME wrote: Tell me again why you are going direct to ghetto rather than just remove the nuts and put new ones on?Looks like there is thread under that nut I work on a tonof brit-E36 M3 that has rust down to an art, and my steadfast belief is tha the best way to deal with broken bolts is to not break them in the first place. So , why are you not considering a torch and some penetrating fluid and a healthy application of patience? There are even sockets made to grap rounded off nuts that might come in handy.

there is no thread under those nuts any more.. they are one with the stud and the only way it is coming apart is to cut/break the studs and use some combination of fire, penetrating oil, finesse, and brute force to get the studs out.

^ This. I didn't even bother trying but I guess it's worth a shot. I'm fairly certain either the nut will round itself off or the stud will shear.

jstand wrote: If you go the route of removing the studs, they may be easier to remove if you can release some of the clamping force of the flange on the stud. The easiest way is to make horizontal a cut into the flange from each side until it reaches the stud. If the studs are pressed in, they will knock out with a hammer easily and can be replaced by through bolts with nuts. If they are threaded the release of tension in the hoop direction around the stud should help break the grip on the rust and with penetrating oil allow them to be removed easier.

Ok, I might give this a shot. Seems like a good balance between 'too much effort' and ghetto. From the backside the studs appear to be pressed in so hopefully they'll just pop out. Anyone see a problem with attacking the flange with an angle grinder?

Cut the nuts off, drive the studs out with a zip gun, go buy new studs and a gasket, done.

In reply to Stargazer:

Not always. I tried to press out the OE studs from the cat back flange of a MINI header. I ended up breaking the bench vice instead.