Help! N51 Exhaust Header Nuts Removal/Replacement

[crowtrobot]

Urgent help needed. Started replacing headers last night, bit off a little more than I could chew I think. After losing a ton of skin, managed to get all but the last nut off, but the last nut was tucked behind a vacuum line for the AC compressor.

Late and frustrated, ended up venting the damn AC all over the engine bay to get at that nut. Got the headers out, but still wondering, what tools are you guys using to make this better?

I've got a flexible 3/8 drive ratchet. Will a flexible box wrench be better here? Universal joint? How the hell can these nuts be torqued?

Advice appreciated, thanks!

[crowtrobot]

Just an update in case anyone searches for this in the future - picked up a 11mm flexible box wrench:



worked wonders for the rest of the work on the manifold stud nuts. Still not easy by any means, but made life a little better.

Performance-wise, new AA headers are night and day on my 128i. The added pull is amazing. NVH-wise, I have found some horrendous resonance/drone at ~2400rpm that's rattling the windows a bit, so I'm hoping I can track this down. Also there's some idle-hunting, which I think may be normal as the DME adapts, only put about 40mi on the car since the install. The way it is currently, not sure the added volume and drone are worth the day-to-day impact for gains at the track...

Will be swapping the PE out for the original exhaust shortly to isolate that part of the system.

[Fume]

Good to know! How'd you torque the nuts for the install if the clearance is that tight? Would seem like it would be impossible to fit a torque wrench in that case so I'm guessing you just tightened it up tight and called it a day?

[crowtrobot]

Originally Posted by Fume

Good to know! How'd you torque the nuts for the install if the clearance is that tight? Would seem like it would be impossible to fit a torque wrench in that case so I'm guessing you just tightened it up tight and called it a day?

The shape of the new AA headers is a little more open in certain places which allowed us to get a shorter 3/8" drive torque wrench on two or three of them to get a feel, then then rest were done by hand.