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On both of my 2004 Aeros the studs failed repeatedly. With several requiring a slow and painful drilling and ez-out adventure.
A previous post, many moons ago, mentioned that they had used ARP stainless steel stud kits with great results. So I tried them on the next car to snap a stud. At first I put anti-seize compound on the studs before insertion and torqued them to spec. About two months later I heard something fall from the engine bay and impact the bottom of the car several times while at speed on the highway. I immediately knew, somehow, that it was a stud. And it was. Of course it was the lower #1 cylinder stud. The hardest one to reach and usually one of the first to fail. So I took them all out, more than half were only finger tight, and flushed out the anti-seize goop with starting fluid (mostly out of concerns about any aggressive solvent entering the cylinders and crankcase) and then re-torqued the studs with red locktite applied. One of the cool features of the broached ARP studs is that they have a 3mm internal socket machined into the stud, which really comes in handy. Then I put red locktite on the nuts and torqued to feel. Which was probably close to 40ft/lbs. I then put a standard saab copper based header nut on top of each ARP nut, torqued to feel, just for good measure. That was five years, and 100,000 miles, ago. So far so good.
When the other Aero needed a water pump, I swapped out the previously replaced oem carbon steel studs, just for good measure. When I went to remove them, two of the studs snapped like they were already well into failure, but a close examination of the fractured studs showed that there was no sign of corrosion or pre-existing fractures. So who knows what that means or how far from failure they actually were, but they had been on the car less than two years. I should also mention that since my first manifold stud adventures began, part of my gas station routine has been to check all fluids, both manifold and turbo studs, tire pressures, coolant hoses, turbo plumbing and vacuumm lines, etc. So if a nut or stud does come loose or fall out, it won't be missing long enough to cause further issues. But so far, with the ARP bolts at least, no more stud adventures.
posted by 72.179.156...
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