Debate on header to exhaust port torque values?

[Maxhouse97]

This is what AI output when I searched for the torque value for the nuts to bolt headers to the engine:

Overview

The BMW E46 M3 exhaust header bolts, specifically those attaching the header to the cylinder head, should be torqued to 16 lb-ft (22 Nm), according to a BMW E46 bolt torque spec guide from Garagistic. Some individuals suggest a higher torque, such as 30 lb-ft, or even 60+ lb-ft in cases of leaks, but the factory recommendation is 16 lb-ft. It's also recommended to use new bolts or apply anti-seize to the threads when reinstalling.


I didn’t realize there was a debate about the torque values. What is the common wisdom from this board?

[Maxhouse97]

Actually disregard … no flipping way Im getting a torque wrench in there. Going by feel.

[discoelk]

Did you ask ChatGPT if that was okay though?

[bigjae46]

I was going to say...I'd shoot myself if I tried torquing all of those bolts with the engine in the car.

[M3llowM3]

gotta get it to the german torque spec... Guten tight

[samthejam]

https://nam3forum.com/forums/forum/main-forum/e46-2001-2006/414-e46-m3-torque-spec-thread-every-bolt-on-the-car-on-diagrams

[Slideways]

Guten tight might not be good enough

The factory uses an oval copper nut that sometimes gives the false sense of being tightened when going hand tight. As you tighten them, there is quite a bit of resistance.

A 1/4" torque wrench with small extension will allow you to get to all the bolts from the top (factory and euro headers). Hand tighten one flange then go back with the 1/4" torque wrench. You might find that there is quite a bit more rotation to get the full torque on the fastener. The gasket really needs to be crushed against the head to provide a proper seal and keep your 500F+ exhaust gases from escaping.

[Ramps]

I’ve never torqued them and never had a leak. Just tightened by feel.

[Cubieman]

I do remember attempting to re-tighten a number of the nuts a few months after installation and was surprised how "loose" some felt, everything seemed to be sealing however.