Exhaust manifold advice - Land Rovers Only

DougG · 11-18-2006, 03:12 PM

I'm in the process of replacing the right side exhaust manifold gaskets. I have all the old hardware off, and the mating surfaces are clean. I have all the new hardware on the exhaust manifold. Some of the bolts are not lining up properly with the holes on the head. They are slightly off line. They will screw in, but they won't go in easy. The bolts closest to the firewall are straight, the two forward of those are slightly off line, the next two are straight, and the two closest to the front of the vehicle are off line. No matter what I do, I can't get them to line up. I did notice that when taking some of the old bolts off, some came off slightly off line as well. Any advice?
Thanks,
Doug

Paul Grant · 11-18-2006, 03:32 PM

You didn't mention the three studs holding the down pipe to the exhaust manifold. Have you loosened them in an effort to align the manifold to the head? If not, you'll find it a lot easier if you loosen them. A word of warning. Whenever you loosen the nuts on the studs use an impact wrench. If you just use a normal socket wrench the likelihood of breaking the stud is great. The act of ratcheting torques the stud until it snaps. By using an impact wrench you may remove the stud but it is unlikely you'll break it.

DougG · 11-18-2006, 03:59 PM

I didn't loosen the studs to the down pipe, didn't think I needed to. I don't have an impact wrench.

Paul Grant · 11-19-2006, 02:10 AM

Well, it's my guess that the weight of the entire exhaust system, which is still attached to the manifold, is what is making it difficult to align it with the head.

DougG · 11-19-2006, 06:28 AM

Thanks Paul, but how come only 4 bolts are off line and the others go in straight. Like I described earlier the two bolts closest to the firewall go in straight, the next two(going towards the front of the vehicle) are slightly off line, the next two are straight, and the next two closest to the front of the vehicle are off line. How can that be due to the weight of the exhaust, wouldn't all of them be out of alignment. I have the exhaust on a jack stand to support the weight.

Paul Grant · 11-19-2006, 08:59 AM

I'm not there, I can't argue with what you are seeing. I just know from personal experience that it is a whole lot easier to simply loosen or remove the three nuts that secure the downpipe to the manifold. Then you don't need a jack to support the exhaust all you do is hold the manilfold in one hand and bolt it to the head.

Maybe the previous owner, forced the bolts in and cross threaded them when he was doing work on the truck. You don't seem to want to take my advice so at this point all I can say is good luck and perhaps familiarize yourself with heli-coils.

DougG · 11-19-2006, 09:27 AM

Paul, I appreciate your advice, and I realize removing the manifold from the down pipe would make moving the manifold around easier, but I don't see how it would help me line up the holes when some holes are straight, and some are not lined up. If the front most hole on the bottom is not aligned, it would make sense if the rear most upper hole is not aligned as well, but the rear most upper hole is straight. I don't have an impact wrench, so you have advised that removing the down pipe nuts with a ratchet would not be a good idea.

DougG · 11-19-2006, 09:34 AM

Paul, what is the worst case scenario by removing the down pipe nuts with a regular ratchet? Do they always break, or just some of the time?

gordo · 11-20-2006, 12:55 PM

Ive broke a few myself and it is never fun. Good tip on the impact wrench Paul. Nothing worse than trying to drill and tap out a head on the truck. Been there done that and seen the green fluid before that I didnt want to see!!

Dude just remove the exhaust manifold from the Y pipe and it that doesnt work, then drill out the holes a bit to make it fit. If you have trouble getting the Y pipe/exhaust manifold bolts loose just soak them real good in PB blaster and maybe try to heat them a bit. They are not as hard to drill out and replace as the ones that hold the manifold onto the head. Good luck. Gordo

DougG · 11-26-2006, 12:36 PM

OK, so I followed everyone's advice and removed the manifold from the down pipe. The holes are still not lining up, even with being able to move the manifold at will. Is my next step to drill out the holes on the manifold? If so, any advice on that? Thanks, and sorry for all the questions, just want to do it right. The nuts on the down pipe actually came off pretty easy with just a ratchet and socket.
Thanks,
Doug

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