Greetings,

I have a 1990 245DL. I am replacing the exhaust system and broke one of the studs between the exhaust manifold and header pipe. I tried a bolt extractor and broke that too. I grinded through the extractor and then drilled all the way through the bolt.

I figure my next move is to re-thread the hole with a tap. Does that sound like the right move? If so, what size stud is it? What size tap do I need to thread a hole that will fit that stud?

Any help, suggestions, experience would be greatly appreciated.

Thanks!

10MM

Just use a bolt

Thanks, Onkel Udo II. It's the stud that's closest to the front of the car. And it seems like I won't be able to get a nut on the bolt with the way the manifold is shaped. I will give it a shot and see what happens.

I had this apart this weekend on my 940. Unless the 240 is significantly different, it is no issue.

Nut still goes on the bottom, bolt drops down from the top. It would be give or take a 10 x 40 mm but you will likely have to buy a 50mm length. Or you could go SAE for that one item and have a wider range of length options at the big box store.

Oh, my envisioning was blurry.

When you said you replaced the studs with bolts, and ran the M10 tap through the manifold flange, I pictured you dispensed with the nuts and put short bolts up through the downpipe flange, threaded into your cleaned-up cast iron.


--
Art Benstein near Baltimore

"Your continuing acquisition of wisdom outpaces the absolute value of my mental decline."

He mentioned re-tapping the hole but I implied (but did not say) to just over size it enough to drop a bolt in from the manifold side...or do not enlarge it at all and just use a 3/8" bolt.

Of course I am becoming more of hack/redneck to older I get.

Hey guys - I appreciate the info and just wanted to report back. It looked unlikely that I would be able to drop a bolt in from the top for that particular side of the flange because the exhaust manifold was in the way. I decided to use a heli-coil for the same size stud and it worked out.

Thanks!