Ok, I did the job this weekend. Before I fixed it, oil was leaking from the engine, below the oil filter housing at a pretty considerable rate, maybe 10 drops a minute. I had 10w40 redline in it, and I didn't really want to go any thicker.
I have heard time estimates between 4 and 7 hours at a shop. I put 4 or 5 hours into stripping it down to pull off the housing. This included:
underside cladding - you guys know the drill, i swear I'm going to wear out those bolts.
power steering reservoir - just undid the strapping and put it to the side with a rag under it as the cap does leak slowly
Drained the coolant
coolant line (above headers) - just makes the access so much easier for the rest of the job. Removed the hose clamps and the bolts holding the metal tube to the head.
headers - 13mm nuts on studs, access is fine with a wrench and a universal joint on a ratchet. Unbolt from down pipe below car. again, access is "fine" with a wrench and a ratchet, but if you're like me and only have jack stands and can only get the car as high as you can lift it onto those stand with your factory Porshce jack and a 35 year old Triumph Jack, then you probably look like T-rex when you're doing this part. I also took off the two bolts supporting the rear section of the exhaust to the car to make it easy to slide the headers out. One of the articles said you could just slide the headers back and it was ok, but I can't imagine, and it was about 5 more minutes to just completely remove them.
heat shields - removing this made me want to stab whoever designed it. It comes out in two sections. where the rear part joins the front part there are 3 bolts, one accessed from the top, two accessed from the bottom with a few ratchet extensions put together for ease. This frees the rear section, and now the rest is socket cap screws, one holding the front part of the head shield on, centrally located below the shield. Pretty much the worst place possible. I removed it from below. The other two socket cap screws are holding the support where the two shields meet to the oil housing. Removed this to make it easier to get the housing in and out of the car.
radiator - I removed this to gain access to the socket cap bolt for the oil cooler/housing connection. It's actually the easiest thing to remove. The bolts for the cooling lines was pretty tight, so i figured, why not. I would recommend doing this. you just undo cooling lines to the radiator wherever you see fit, removed the airbox support member (4 10mm bolts), pop the 4 little clips off holding the plastic shroud to the front of the radiator, unplug the three plugs (cut 2 zip ties holding the wires) and it slides out. Now that I've written it out, it sounds like a lot of work, but it's not really once you're in this deep.
oil pressure gauge - Removing the oil pressure unit required a 24mm wrench. I bought a standard 24mm from Napa because it was all I could find, I thought I might need to modify it to fit, but it was ok. Due to the tight space for turning the wrench, I had to do one turn from the top of the engine, one turn from the bottom of the engine. fun. In retrospect I imagine this could have been left on the housing...I don't know why it needed to come off. The article listed in this thread says to take it off.
oil pressure relief valve - 24mm socket turns this part out, be careful, it's expensive, haha.
...and finally the housing. This is 4 13mm bolts, the bottom right one is quite hard to find. Other than that, it is straight forward.
As Pete had mentioned, the job pretty much just involves turning bolts, but figuring out whether to access those bolts from the top or the bottom of the car, and just getting your hand in there is the most time consuming part.
My old gasket was the newer style with the metal gasket with 3 gasket surfaces molded to it. It was pretty flat on one side though, and it did clearly seem to be what was leaking. i cleaned everything and oiled the gasket and put it in place with the housing, which is a bit tricky as it seems to only be able to come from the bottom of the car. i just lined everything up and put the top bolts through the housing and gasket and then hand tightened everything. There is a special tool you put in place of the oil pressure relief valve when installing the housing so you don't mess the valve. you tighten everything on and then remove this tool and insert the valve. Easy enough though it was a bit difficult to get out after everything was tight. especially because the end of the tool is knurled. So I grabbed it with a wrench and managed to get it to come back out.
That's pretty much it. I cleaned the oil and I built everything back up. I put coolant in the car, turned it on, warmed it up, and then turned it off and changed the oil. I don't believe I had oil in the coolant or coolant in the oil. I had replaced both recently as I had done the Timing belts and changed to synthetic oil, but I didn't want to take any chances.
Everything is working well. I drove it around the block with the cladding off to see if I had any dripping. There doesn't seem to be any oil leaking anymore, which is a relief.
The rebuild took about 6 hours, so over 10 hours total, but I would imagine i could have made it in 7 with a shop.
The only thing that is bothering me is that the car, especially at first, didn't want to restart when it was hot. When I turned it off I had to wait several minutes to restart it. This seems to have gotten better since Saturday, but I can't explain it, any guesses?
Hope this helps someone. I was dreading doing this, almost had a shop do it, but now I can go buy myself new snowboarding kit instead.
-Phil
