Questions:
1) Bentley's X5 book says to get the BMW tools to hold the cams in place. What is their purpose? Is there a work-around, or should I purchase those tools? Cost?
You will need them to set the cam timing correctly, especially upon assembley because, if its off you may cause alot of damage to valves and such. Id reccomend getting them
They look something like these:
http://www.denlorstools.com/shop/ima...lignment_2.JPG
And it would cost about 200-500$ a rough guess.
2) I intend to keep this vehicle for a long time. Are there other things I should do, while it's down? Are valves, valve guides, cam chains, etc., problematic? Should I pull the other head as well?
Yes, when the head is off, take it to a head guy so he can resurface it and check whats wrong with it, also id do the valve seals since about 25% of us on here are smoking at extended idle due to worn valve seals. Maybe chain rails they go bad sometimes, also get new chain tensioners, febi bilstein ones are good. Valve cover gaskets.. Also dont forget new headbolts since you cant reuse them.
3) I intend to pull the head(s) with the engine in the vehicle. Is this best?
Honestly im not sure, ive only done this to a 550, its the NOT same engine, so everything is NOT the same. But we just dropped the engine out with the subframe and gearbox becaue it was much easier to do that and there was more space. here it is:
4) Is a leaking head gasket a common problem? I didn't notice a high temperature on the gauge, but I was driving around a strange town, late at night, trying to find a motel and a restaurant. It might have over-heated, and I didn't notice. On the other hand, prior to over-heating, there's usually a "check coolant level" message, with the accompanying "ping". I didn't hear that. Water pump was replaced about 10K ago, so I don't suspect a coolant leak. Checked water and oil levels before I left home; all OK. It doesn't leak water, or use oil, usually. I don't know why the head gasket sprang a leak. Any suggestions?
Not sure, someone else should chime in. But its not Very common i dont think, pretty rare. The 550 i worked on had other problems and was overheated a couple times which ruined the seals, guides, and gave the head a slight uneven surface, "twist" to it
Hope any of that helps
