Hey guys. I've a quick question. Should the exhaust pipe connector gasket, that is, the metal ring that goes between the exhaust manifold and exhaust down tube, be the same for all W123 models? I have a 1979 240d with an audible leak from this area, though I replaced this gasket when I transplanted the engine. Cheap parts suppliers show the same parts number for all 123s, though it seems as though the five cylinder/turbo models would have a larger exhaust system. I'm really having a hard time getting this sealed. Despite the fact one of the bolts is hard to get a socket on, I've been able to apply a good amount of torque to the fasteners with no avail.

Thanks!

Seth

the two sizes should be obviously different - iirc they are 50mm and 60mm in diameter.

would the larger not fit at all? Or do I just need to lift some weights? I had a pretty good breaker bar on this thing, I feel like anything more would just be ridiculous. Anyone else experience this? I can't find multiple part numbers via a google search...

A bolt can put up quite a bit of resistance if it wants to. It seems that exhaust bolts are very likely to get seized. You do want to be careful when try to break things loose; the bolt may be more willing to shear off than the nut breaking loose... You might want to try B'laster or something similar for breaking loose your bolts. Also CRC's "Freeze off" seems to work pretty well.

Try spraying a light coat of paint or if you get some Dykem blueing, cover the ball seal and assemble with the proper torque. Remove the ball and look for an uneven contact surface around the ball on both sides. If you have a high spot somewhere, you can take it down and re-test. Clean the fasteners of rust and torque dry. Too much torque will pull the studs out of the casting. Look for evidence of that happpening already.