Hey guys, I'm changing out all my exhaust studs and I've run into a problem - they're too loose! I was able to get most of them most of the way, or all the way in by hand, and basically just screwed them in until I couldn't turn them with my fingers anymore. Two I had to use the double nut method, but once I got them in, they were super loose - I can turn them very easily. And I tried putting one of the self-locking copper nuts on one of the others, and the stud started turning as soon as the nut was snug. If I turn them all the way in, they're too short, so what do I do? Anyone had this problem before? Most of the old studs came right out (nuts rusted to studs) when I took the exhaust manifold off, but I didn't think it was a big deal.
-
-
Red high temp loctite worked for me
-
That would work, but I'm not so sure I want to do that in the event I ever need to replace them in the future. I actually installed them with anti-seize.Comment
-
And I'm curious why the copper nuts are being sold vs the original steel non-locking nuts, if I can't get the copper nuts on without the studs turning? I just did a search and it looks like they're not supposed to be any more than hand tight.Comment
-
Where did you come across that the nuts need only to be hand tightened?
As for a copper-plated lock nuts ..... this is something you can search and come back with lots of results. In short, better thermal capabilities but a bit more expensive (plenty of oem's use them).Comment
-
Sorry, studs should be hand tight (allegedly). Not the nuts, obviously.
Post 3: http://www.r3vlimited.com/board/showthread.php?t=253700
Thermal capabilities aside, I'm just not getting why they're lock nuts if the studs are only supposed to be hand tight, and start turning as soon as the 'lock' portion of the nut is on the thread. Without loctite, which I don't see as a good idea, I just don't see how I'm going to get the nuts on without driving the stud all the way into the head.As for a copper-plated lock nuts ..... this is something you can search and come back with lots of results. In short, better thermal capabilities but a bit more expensive (plenty of oem's use them).
Of course this wouldn't be a problem if I had just bought the IE studs that you install with an allen wrench for one extra dollar.Comment
-
The studs have a lot of thread engagement to the head. Some will come out when you loosen the nuts. Just thread the ones that pull out with a little loctite and torque the nuts to spec with a new gasket. The gasket will squish and should prevent the studs from backing out.
Head studs are the same. They are installed with anti seize, but have so much thread engagement that they won't ever back out. The gasket is kinda like a split washer and has a spring like effect. Those gaskets are one time use.Comment
-
This is what I bought and I was about to say "they're exactly the same as what I took out" but before I hit submit I decided to go double check so that I don't make myself look stupid, and it's a good thing I did because they're actually 2mm shorter than the old ones. What the fuck? It says on Pelican that they fit my car, but they clearly don't. RealOEM says they're 8x40 so it's not just Pelican that has it wrong. Edit: just noticed that RealOEM says they're 10x40. That's not even close.
Does anyone know the correct part number?Last edited by rturbo 930; 05-09-2015, 06:51 PM.Comment
-
they are M8 x 40mm, you linked the downpipe studs on realoem, not the head to manifold studs
intake 07129903964 (11 req) and 07129908142 (3 req long ones)
exhaust 07129908134 (12 req)
http://www.realoem.com/bmw/enUS/show...diagId=11_1908Last edited by digger; 05-09-2015, 07:20 PM.89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...
new build thread http://www.r3vlimited.com/board/showthread.php?t=317505
Comment
-
I am so confused. The ones I took out are 8x42. The ones I bought are 8x40, and if I screw them all the way in, they're about 2mm too short. Are they not supposed to be screwed in until they bottom out? If I don't screw them all the way in, they're too loose, and I can't get the lock nut on without the stud turning further into the head.
This should be a really simple job, and so far, it hasn't been. I'm thinking about taking all the studs back out, putting the lock nuts on them, and then screwing them in like a bolt.Comment
-
2mm short for what exactly? if you put the manifold and nut on how many threads protrude through the nut?
ive got a bunch that are from old heads and they are 40mm89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...
new build thread http://www.r3vlimited.com/board/showthread.php?t=317505
Comment
-
2mm too short to engage all the threads of the nuts. No threads protruding. On the old studs, it's only the tip of the bolt that sticks out. I'm using an old stud that came out with the nut still on it for reference.
Pics:
Old, longer stud with nut:
This isn't fully tightened but it's tight enough. Stud was turned in until it bottomed out.
Last edited by rturbo 930; 05-09-2015, 08:09 PM.Comment
-
Didn't see your edit til now. At first glance it looked like the stud (#7) was going into the head side of the manifold. Whoops. Anyway, so I apparently have the right studs, yet they don't seem to fit, unless I'm installing them wrong, and they're physically shorter than the old ones I took out.
I feel like there's something very obvious I'm missing. Any ideas guys? The pics above show the issue.Comment
-
Comment