Found my exhaust leak :-(, Broken ear weld - now what? Options

[ThinAir]

I found the exhaust leak on #4. I expected to find that I just needed to tighten things up, but no - that would be too easy!

The welds on one of the "ears" that goes around the exhaust stud has started to tear loose and it took some of the exhaust pipe with it. Now I've got two small holes in the pipe where the welds used to be. (IMG:http://www.914world.com/bbs2/html/emoticons/sad.gif) These are stainless steel heat exchangers.

My temporary fix for now was to fill the holes as best I could with some copper impregnated hi-temp RTV that I use for exhaust gaskets to make sure I don't get a leak. I'm letting it cure overnight before restarting the engine. It can't be any worse than it was.

The question I've got is about fixing it when the time comes (hopefully winter). I'm sure I can find a welder who knows how to work with this stuff, but I'm wondering about the size and alignment of the ears. These have got to be the hardest HEs to attach to the heads that I've ever dealt with. It takes all kinds of finessing to get them onto the studs and I'm always certain I'm gonna scrape the threads right off the studs.

I don't think I can expect any old muffler shop to make these right. Can anyone point me to a source that I can ship to for repairs that understands 914s and can make them right?

[scruz914]

I am currently dealing with the same problem, except my break is clean at the weld. RacerChris recommended that I have the ear rewelded only with TIG and not MIG due to it being SS. Chris also suggested that I check the other ears for cracks.

You may be able to reuse the existing ear. Is it badly twisted?

-Jeff

[ThinAir]

It's not visibly twisted. It's only when I mounted them on the engine that I noticed that they were so difficult to line up with the studs. My son tells me that the SS HEs for 2.0L Type IV engines were/are only made by SSI and that this is a common problem.

[ChrisFoley]

The material is fairly thin and people typically overtorque the nuts. Add that to the fact that the factory workers usually use a small bead with low heat to prevent overpenetration.
BTW, you've just screwed the guy who will do the repair weld for you by squeezing RTV into the crack. (IMG:http://www.914world.com/bbs2/html/emoticons/ohmy.gif) It may be a good temporary repair (I doubt it) for you but it means more work (time, ie expense... and cussing) later on.
To do the repair really well requires a cylinder head (or even a complete assembled engine turned upside down like I use to build exhaust systems) to attach the pipes to. This way the weldor can make sure the fit is good before finalizing the repair.

[JerryP]

I had the same problem. When I took my exchangers off I found they had been rewelded more than once and 2 of the welds were cracked. The position of the ears looked a little off as well, like they had either been bent or were welded somewhat askew. Luckily I had a spare set of SS exchangers. Vastly improved the car with regard to driveability once I got rid of the leak and a changed out the muffler which had a few pin holes.

Anyway, I'm pretty sure whoever did this just rewelded the existing ears which may have worked for a while, but never while I had the car. I'm guessing someone can save the SS exchangers but I wonder if it might be worth it to try and get a cheap spare set(non SS) in the meantime...always good to have.

[ThinAir]

QUOTE (Racer Chris @ Jun 9 2005, 04:51 AM)

BTW, you've just screwed the guy who will do the repair weld for you by squeezing RTV into the crack. (IMG:http://www.914world.com/bbs2/html/emoticons/ohmy.gif) It may be a good temporary repair (I doubt it) for you but it means more work (time, ie expense... and cussing) later on.

Well for now the temporary repair worked. I started it this morning and now I can hear how noisy the cromoly push rods are when they are set with .006" clearance!

Fortunately, I've got spare heads around for a welder to use as a guide. I promise that I'll be very nice to my welder and clean them up well myself before I ask anyone to work on them.

I appreciate the heads up about cleaning them up. So Chris - can I send them to you for repair?

[ChrisFoley]

QUOTE (ThinAir914 @ Jun 9 2005, 11:16 AM)

Chris - can I send them to you for repair?

Yes, if you can't find someone local who you have confidence in, I can do it.

[ThinAir]

Thanks, Chris. I'm hoping to make it until winter when it will be time to put the teener away while it's snowing and I drive the Honda.