Replacing Cat, removal question

[atle36m3]

Hey guys. i will be replace my cat with a new bolt on unit this week. I was wondering if there are any special tricks with the exhaust header bolts? i have been soaking them in pb blaster since they are all nice and rusty.

i can see that there are little holes on the top of each bolt on the header, do you need to put something in there to keep the bolt from turning? i wouldnt think so but i want to know before i break something...

thanks!

[IronmanE30]

That hole in the top of the header flange is the top of the stud which should stay in the header pipe. If not it is no big deal and can be replaced with a new stud and a dab of red locktight which will make it stay put the next time you work on the exhaust system. Note: Do not use locktight on the lower portion of the stud threads where you are going to put the nut on. I use a long extension with a swivel next to the socket and my largest breaker bar on the end. One of two things are going to happen. The bolt will break free and with the help of the big breaker bar, you knuckles should still be intact or the stud will bust. I have not had a bolt break on the E30 maybe it is because of the special nuts that BMW uses or I have just been lucky.

Cheers,

Jim

[atle36m3]

That hole in the top of the header flange is the top of the stud which should stay in the header pipe. If not it is no big deal and can be replaced with a new stud and a dab of red locktight which will make it stay put the next time you work on the exhaust system. Note: Do not use locktight on the lower portion of the stud threads where you are going to put the nut on. I use a long extension with a swivel next to the socket and my largest breaker bar on the end. One of two things are going to happen. The bolt will break free and with the help of the big breaker bar, you knuckles should still be intact or the stud will bust. I have not had a bolt break on the E30 maybe it is because of the special nuts that BMW uses or I have just been lucky.

Cheers,

Jim

thanks for the info jim!

[5KWattson]

any time i do exhaust work or if the bolts look like there might be a slight chance of stripping/breaking, i spray PB on them that shit is amazing i think its like 4.50 a can but it is damn worth its weight in gold