Help! 3 exhaust studs backed out! (Page 1/2) Modesto JUN 22, 08:24 AM I have less than 200 miles on my 3.4 swap and I used the exhaust manifold studs from Rodney Dickman. I installed the studs using the appropriate (E6 or E7?) socket torqued to the 25 ft lbs specified in the manual. Then put on the gaskets, manifolds, etc. applied antisieze to the threads before torquing down the nuts. I'm reading now about ultra high temp threadlocker. Is that my only hope? What am I doing wrong? pmbrunelle JUN 22, 08:54 AM What gaskets did you use? Modesto JUN 22, 11:19 AM The Felpro that looks like a direct factory replacement. pmbrunelle JUN 22, 12:57 PM quote Originally posted by Modesto: I installed the studs using the appropriate (E6 or E7?) socket torqued to the 25 ft lbs specified in the manual. I don't think the service manual would have a torque spec for exhaust studs, since the Fiero doesn't use exhaust studs from the factory. Anyway, the practice of tightening studs in the threaded holes seems bizarre to me. I think that finger-tight is standard. I have to get to work now, so I don't have time to think about the subject in-depth. Modesto JUN 22, 01:37 PM Well I used the value for the bolts, but the Saturn's (since that is the original application) call for like 8lbs for the studs and 16 for the nuts. Rodney said he had never heard of them backing out, and suggested I just tighten them up to 35 or 40 ft lbs. pmbrunelle JUN 22, 11:12 PM I have had no epiphany. ARP suggests installing head studs finger-tight: https://arp-bolts.com/p/faq.php I would also avoid overtightening the studs to facilitate future removal. Do your manifolds sit flat on the heads? I don't know what could go wrong as such, so I'm grasping at straws. I had a problem with cheap gaskets, but that was fixed when I used the Fel-Pros. How is the ignition timing on this car? Is it OK? Too much retard would increase exhaust gas temperature, which would heat the manifolds more, making them move around. Modesto JUN 23, 12:04 AM The timing was set per the FSM instructions. I'm really at a loss as well. Patrick JUN 23, 12:06 AM quote Originally posted by Modesto: I'm reading now about ultra high temp threadlocker. Is that my only hope? That's what I would use. Keep in mind though that thread locker won't work properly unless all threads are clean and dry before application of the locker. Out of curiosity, I google searched how tight to make the studs. You definitely do not want to tighten them to the same torque value as a comparable sized bolt... the reason being that unlike a bolt, a stud is either bottomed out in the hole or has reached the end of the threads on the head side of the stud. Over-tightening a stud therefore can cause issues. Good article Here. Modesto JUN 23, 01:15 AM That is a very informative article! Looks like when the bolts come in I'll need to address some potential issues. On the upside found in my notes that I only "snugged" the studs. I couldn't finger tighten them because they were too tight in the threads, which looks like may be by design, though I don't know if they bottomed out or were shouldered. It looks like the nuts were taken to the higher side of the FSM torque value at 27 ft lbs. All the others are tight as can be, odd that those 3 decided to boogie. pmbrunelle JUN 23, 12:23 PM quote Originally posted by Modesto: It looks like the nuts were taken to the higher side of the FSM torque value at 27 ft lbs. All the others are tight as can be, odd that those 3 decided to boogie. If the Rodney Dickman nuts are prevaling-torque, then the FSM value (which applies to the stock bolts) is not applicable. When turning a prevailing-torque nut, a large amount of the torque is used to combat the thread friction. Less torque is "left over" to actually clamp the joint together... usually it's a certain amount of clamping load that is sought after. So the torque spec should be increased with a prevailing-torque nut. Did the tightening "feel good" when you were doing it? A fixed torque spec makes sense in the factory with repeatable parts, but in the context of automotive restoration, strictly following book torque values can lead you astray. We regularly see people here snapping off their brake caliper bleeders as they torque to the book spec. With experience, it is possible to get things screwed together without a torque wrench, feeling for the torque rise indicative of the parts being clamped together, rather than the torque value itself. It's rare that I reach for a torque wrench while working on my Fiero.