Exhaust manifold removal/reinstall

[iptman]

I'm replacing my exhaust from manifolds back and I figured I'd pull the manifolds to get them ceramic coated as well as replace the studs and nuts. The last 2 nuts on the rear manifold are a bitch but I did get them off. When I go to put the manifold back in are there any tips that will make those two any easier? I was a half second away from posting a "these nuts are impossible" thread before I got the last one out. And just for some self deprecating humor, I pounded on the manifold with my 2lbs dead blow about 5 times before realizing there was that last nut/stud back there. What the hell is that one for anyway?

 

[Mighty690]

I'm in the same boat with those back two. what kind of wrench did you finally have success removing them with? Any luck, ideas?

 

[iptman]

I used a combination of 1/4 and 3/8 drive ratchets and a closed end wrench at different stages of getting them off. I'm really not looking forward to putting all back together either.

 

[Kernal]

Got any photos of the problem area and tools you used?

 

[clownmidget]

I would advise running a tap into each of the manifold stud holes to properly clean up the threads. Then use the newer Toyota studs with the torx heads. Read the service manual for proper torque specs on installing them. Then use new manifold gaskets & nuts. I've found the job goes so much better when you use new hardware with freshly cleaned threads.

 

[DARKNESS]

I broke the studs that connect to the y pipe on both manifolds. I managed to extract them from one but not the other. I wound up buying new ones, so if anyone needs just one manifold let me know.

My studs in the block all came out very cleanly. One point on installation: I think the proper way to install them is not to torque the studs into the block. Put them in hand tight with loctite, let it dry, then put the manifolds on and torque to spec. Of course I didn't learn this until after I installed mine. Probably not a big deal, but if I do it again that's how I'll do it.

 

[mikedamageinc]

I just replaced my exhaust too and broke one stud on each manifold downpipe. I had to take to manifolds off to drill out and retap the studs since they were basically welded in there. I just used new replacement studs for the heads. Be careful on tightening them, i put the studs in first and started to do the 29#/ft but it started to feel looser as it was going tighter so i stopped quickly and just snugged the rest up by hand. BTW that was the sequential center-out method too, probably should have tried the DARKNESS method above. I also didnt run a tap, couldnt find the right size locally and didnt want to wait for mail order.

Anyways the rear studs werent too bad. Climb in the engine bay and reach back there with a box or open wrench and snug it up little by little. I might have been able to sneak a ratchet in there too with no extention, cant remember now.

Are you getting the heat shields coated too? I thought about that after putting mine back together. Manifolds were too much so I coated downpipe back.

 

[iptman]

I saw nothing in the FSM regarding the torque spec for the studs. If you guys found it let me know where. I did see the torque specs for the nuts for both the manifold to head and Y pipe to manifold but not for the studs themselves.

 

[DARKNESS]

I think that's because they're supposed to be installed like how I mentioned.

 

[QuackAxel]

I would advise running a tap into each of the manifold stud holes to properly clean up the threads. Then use the newer Toyota studs with the torx heads. Read the service manual for proper torque specs on installing them. Then use new manifold gaskets & nuts. I've found the job goes so much better when you use new hardware with freshly cleaned threads.

What size "torx" socket fits the studs? They look more like a star "e6"?? Will a 12 point 6mm fit them? I have 3 that are being stubborn!

 

[MissahPapaJ]

I broke the studs that connect to the y pipe on both manifolds. I managed to extract them from one but not the other. I wound up buying new ones, so if anyone needs just one manifold let me know.

My studs in the block all came out very cleanly. One point on installation: I think the proper way to install them is not to torque the studs into the block. Put them in hand tight with loctite, let it dry, then put the manifolds on and torque to spec. Of course I didn't learn this until after I installed mine. Probably not a big deal, but if I do it again that's how I'll do it.

I usually copper anti-seize and give them a tiny sqeak of torque using the double nut method. Haven’t had one fall out yet.. but I’ll keep you posted.