E60 - N52 Exhaust Flange Leaks?
 

Greetings!
Let me get this out of the way and say that I have a bit of that OCD / Perfectionist thing can't help it.
Five years ago we helped our older son get a 2008 528i (LCI) with the N52 engine. The car had about 110k miles on it then. He's had it for 5-years now and has put over 50k miles on it. Incredible vehicle that still rides like new at 165k miles, but admittedly there are a lot of leaks.

Here is the issue:
- Front subframe is out to replace the oil pan gasket
- Found out that the main oil leak is the rear main seal, so I have to drop the transmission after I get the engine bay work completed
- All coolant hoses, water pump, thermostat, and water pipe gasket and O-ring being replaced
- Already dropped the exhaust system as part of the transmission removal
- Removed the passenger side engine mount bracket to make it easier to get to the coolant pipe connection to the block

Now that I'm in there, I can't help but notice that it would never be more convenient to pull the headers/CATs and replace the flange gaskets, studs, and nuts.

So, does it make sense to replace the exhaust flange gaskets? Do they ever leak?

Thanks in advance!

Terry
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With the condition yours is in I woudn't bother. I don't hear much about the head to manifold gaskets going but the lower ones can go(that being said they are pretty easy to replace under the car

Thank You neilv, for your response.

I was tempted to dig in further, but decided not to. It was actually nice to start installing some parts before I move on to drop the transmission out to do the rear main oil seal.

Kind regards,

Terry