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Thanks to everyone for their advice on freshening up my cylinder head. I wish I could say I've got to the point where I can actually make use of it, but I've hit a snag removing the head. I cut my teeth on a NA headgasket job last year, so figured the turbo one would be a little trickier, but not by much. Everything unbolted like a charm, and I opted to go with the technique in the FAQ to leave the turbo and exhaust manifold in place, and maneuver the head towards the intake side, presumably slipping the exhaust studs out through the manifold. Looked good on paper, but I can't for the life of me get the head out! Even with a lot of jiggling from side to side, I still get stuck on those studs, and now I'm worried that I'm scraping up the head on those two raised points on the block.
Has anyone actually been successful with this technique, other than the person who put it in the FAQ? I'd like to avoid removing the turbo, since this is an on-the-street job and it looks almost impossible to do anyway, without the resources of a real garage at hand. Can I detach the turbo from the exhaust manifold and lift up the head with the manifold attached, or is the manifold still bolted to the block somehow? Is there any flexibility in the coolant/oil lines on the turbo so I can jack it up with the exhaust pipe slightly, possibly easing removal?
Any insights greatly apprectiated!
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"Can I detach the turbo from the exhaust manifold and lift up the head with the manifold attached, or is the manifold still bolted to the block somehow?"
I would think yes because your 93 has the Mitsubishi turbo that attaches with easier to reach nuts. Shouldn't take long to detach turbo compared to removing the head. Might as well try your idea propping up turbo and go for it at this point!
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I was able to get mine off using the technique. However, to get back on I needed to loosen four nuts on the exhaust manifold on the side and one underneath. That may help for removal also. I also used some rope to tie the intake and exhaust manifolds as far away from the block as I could.
Brian Mee
92 945T
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Thanks, Spook and BrickDad - this addresses my particular issue perfectly. Have no idea how I'm going to reach those bolts, though - I can't even see the one underneath, and clearance is so tight from above for the other four. From below, there are a lot of obstructions - but hopefully with good lighting and cooperative weather I'll figure out how to get at 'em.
I also just thought of another possible technique - remove the exhaust manifold studs from the head while it's still on there. It seems like they're just long enough to get two nuts on each one. It also looks like there'd be just the right amount of wiggle room from the manifold to squeeze the gaskets into place and then thread the studs back in on the re-install. Maybe this is a pipe dream, but if I get desperate I'll give it a shot and post the results.
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I just got the head off! After almost giving up on my stud removal theory (most of them simply wouldn't budge) I finally managed to get the lower stud off exhaust port #4 (closest to the firewall), the upper stud off #3, and the upper stud off #1. The removal of the 2 rear ones allowed the head to slip off with amazing ease. For a car with almost 300,000 miles, the head and block look terrific - just a little carbon buildup on the head that I'm removing with carb cleaner, and some cement-like substance on the block from the couple of tiny gasket cracks that a stop-leak treatment took care of a couple of years ago, before I knew any better (and which fortunately comes off easily with a razor blade). I'll post back when I actually try the re-install. Ironically, with the head off, it's so easy to get to those two bolts holding the exhaust manifold bracket the the block, AARRGH!
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I re-installed my head today, and found that the process went just as easily as taking the head off. Definitely the key to getting the most maneuverability from the head with the exhaust manifold bolted to the block is to remove some studs. The only thing to watch out for were the new exhaust manifold gaskets: hanging them off a single upper stud was fine, since they hang down but don't go past the bottom of the head, so you can just swing them up into place and thread the missing stud through the lower hole once everything is in place. But hanging from a single lower stud is problematic, there's way too much risk of damaging the gasket while maneuvering the head into place, since it swings far below the head surface.
I solved this problem by installing the new spark plugs in the head while it was off, then taking a small zip tie and looping it though the hole in the one gasket that didn't have an upper stud to attach to, then looping the other end around the tip of the neighboring spark plug. This kept the gasket out of danger, then after the head was safely in place, I cut the zip tie while holding the gasket, and carefully threaded the missing stud in through the outer manifold side.
Of course, I was very lucky to get 3 studs out while the head was still in place. I tried removing the other exhaust studs when the head was out and I had a better angle, only to find the remaining 5 completely stuck. So even though this technique ended up working, it very much depended on luck for the outcome. Even with the head out of the way, those two bolt heads holding the exhaust bracket to the block were so corroded that I would have never been able to get them loose. So if I hadn't been able to get those studs out it would probably have been a tow to the garage - and a great deal more expense. Definitely worth a try for those in a similar bind.
Now hopefully I did a good enough job of cleaning everything up and tightening to spec - or this whole exercise might have to be repeated in a few months! :)
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You are right. That underneath nut reminds me of working on the 86 Jaguar! I spent a long time with various 12mm wrenches reaching down from above and up from below during that process. One handy tool was an adaptor thing that allows you to put a socket on the closed end of a normal wrench so that it will fit if there isn't enough room for a real ratchet head.
The stud removal method sounds technicaly correct, however you open the possibility of breaking off a stud, which is not too bad if you were going to send the head to the machine shop anyway.
Good luck.
Brian Mee
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Let us know how you make out and any edits that might be good for the FAQ.
Steve
--
See the 700/900 "FAQ" at the menu bar top screen left side.
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Dear benfingland,
Hope you're well. The following may help:
http://www.brickboard.com/RWD/volvo/1519555/940/960/980/V90/S90/head_reinstallation_question.html .
Yours faithfully,
Spook
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