- Because it's hard to get in there and see the camshaft seal, I'm skeptical that it can be diagnosed properly without taking the car apart. Could an apparent oil leak (there's some drippage on a hose underneath the left head) be caused by anything else? How should I go about independently diagnosing this leak? Should I bring this somewhere else for another opinion?
You can always go to a separate mechanic for an independent opinion. In fact, I would recommend it. However, it isn't that hard to diagnose. All you have to know is what you're looking for, which in this case is where the oil is coming from. If it's leaking from the front cover (which covers the timing belt) just below where the cam sprocket is located, it's a pretty good bet the seal is what's leaking.
- I understand that a leaking camshaft seal can compromise the timing belt, leading to a catastrophic engine failure and damage (see this post). Supposing I do have a camshaft seal leak, and the timing belt, pulleys, water pump, and thermometer are all gross and oily, what should I replace? Keep in mind that I replaced the timing system one year ago (see above). What if all these components don't look dirty/oily?
If it is leaking and there is oil on the belt, change it. Oil will deteriorate the belt and it's one piece of equipment on your vehicle which you don't want compromised. Since timing belts are most easily obtained as kits (which are usually not much more expensive than a the belt itself), your best bet is to replace all of the same parts so you can be assured of another 60k trouble free miles.
- In the timing belt removal section of my repair manual, it says not to rotate camshaft sprockets after the timing belt has been removed, else the valves will be damaged. However, in the camshaft sprocket section, it says I should remove the timing belt assembly before loosening the camshaft sprocket bolts, which seems super risky if they're not supposed to be rotated. Doesn't it make sense to loosen these bolts with the timing belt on, then remove the TB, then remove the sprockets?
I believe they are saying this so as you don't put undue stress on your timing belt (coming off and/or going on). When you are removing the sprocket, you still don't want it to turn any. You need to lock the cam in place and then loosen the bolt for the sprocket.
- I am an amateur, but enthusiastic auto (and bicycle!) mechanic, but I've never done any engine work. I had no problem with rear strut replacement and two front axle replacements -- both of these are relatively easy on my car. Who of you have confidence in me? What could go very wrong that I should look out for? Do I need any specialized tools? I have one small and one large torque wrenches, and many sockets. No air tools. I'm hoping to avoid a rusted-part disaster since the whole thing was taken apart and reassembled 1 year ago.
I'm not going to tell you what to do, but needless to say, this isn't a job for the uninitiated. There are a lot of gotchas. The big one being aligning your cam timing. You didn't say, but I believe your engine has four cam shafts which have to be time along with the crank. If you don't get this right, you will most likely have cost yourself an engine. If this is something you fell you must do, have a competent friend come help/watch to ensure you are doing things right. You can watch some of the videos on YouTube, which may be of assistance.
NOTE: I just looked online at the engine which you probably have. Depending on which one it is (2.0TC, 2.5, or 2.5TC), it could have 2 or 4 cams. If this is one with 4 cams, I believe it has cam phasers (used in variable valve timing). If so, I WOULD HIGHLY RECOMMEND YOU NOT DO IT YOURSELF. There are just too many variables to try and tell you to avoid while doing the work and putting it back together.
- Do I need to remove my radiator for this job? How about drain the oil? Drain the coolant?
For the most part, no.