Sunday, July 25, 2010
I got a late start today because I just couldn't fathom the idea of getting up early on my birthday. The weather forecast also promised 90+ degrees with high humidity so I was not exactly rushing out the door to work on the car if you know what I mean.
In any case, I got to work around 1:30 and managed to accomplish the following before leaving at 7PM:
- Removed the cruise control unit and airbox
- Removed the engine driven fan / clutch assembly
- Removed the alternator cooling ductwork
- Loosened the bolts holding the power steering and water pump pulleys
- Removed the belts
- Drained the coolant via the radiator drain
- Drained the ATF from the power steering system using my optimal flush method
- Removed the water pump and installed the new unit
- Disconnected both negative and positive battery terminals from the battery
- Removed the alternator
- Removed the power steering pump
- Removed the oil pressure switch and VANOS oil line from the oil filter housing
- Removed the oil filter housing from the block
- Cleaned up the block in the vicinity of the oil filter housing with brake cleaner
- Cleaned up the oil filter housing and reinstalled it with a new gasket
- Installed new VANOS oil line with new crush washers
- Installed new oil pressure switch
I had originally planned to do an "official" power steering flush as part of this work but quickly ruled that out because I didn't want to waste any more time trying to acquire the necessary fittings. Fortunately, the ATF that I purged from the rack was still in very good shape so I know I won't be doing the new pump any harm by swapping 90% of the fluid again. Truth be told, this is exactly the way a technician would do it.
Even after I drained the radiator, when I removed the water pump a bunch of coolant flowed out of the block. I was expecting some coolant but not that much. Needless to say I didn't have a drain pan underneath the car at the time and covered the floor in coolant. I hosed the floor down and then got back to work.
Believe it or not, until now I had never removed the air conditioning belt so I didn't know exactly how to de-tension the belt because it is equipped with a different tensioner (hydraulic) than the mechanical tensioner I've worked with before. I figured it out pretty quickly, however. Both belts were showing their age and definitely needed to be replaced. Mike Miller of the BMWCCA has more than once recommended 60K as a proper service interval for good quality serpentine belts. Crappy belts on the other hand, might not last as long, so that's why it's important to check them at least once a month.
I was somewhat confused about how to remove the power steering pump, as the new pump was assembled in such a way that it appeared to require only two long bolts to install it, but as it turns out it is installed using a total of four bolts, including two bolts accessible from the rear of the assembly. Oddly enough, one of the brackets provided with the new unit will have to be removed from the pump to install it.
The oil filter housing gasket was very hard and remained stuck to the block when I removed the housing. I carefully peeled the gasket from the block and then used some duct tape (the only thing I could get to stick) to close off the oil passages before spraying everything down with a can of brake cleaner. This wasn't the least expensive or the most environmentally friendly way to do this but I needed a stream of degreasing agent under pressure and this did the job. For whatever reason I don't yet have a compressed air cleaning wand in my tools arsenal that I could use to spray a more friendly degreasing agent (like the ZEP citrus stuff) but I plan to buy one soon.
I had some difficulty finding a torque spec for the six bolts that hold the oil filter housing to the block. I did find an obtuse reference in the TIS for 40Nm and that's probably safe for a cast iron block, but generally speaking most of the block fasteners have relatively low torque specs in the neighborhood of 25 Nm (18 ft*lbs) so I went the conservative route and torqued to 30 Nm (22 ft*lbs). I think this will be acceptable because I could feel the housing pivoting over the gasket so I knew it was doing its job. Whatever the torque spec, the key to installing the housing correctly is to evenly torque the bolts so the housing mates evenly with the block. I had to use a 12" extension and a deep 13mm socket to torque the bolts.
I'm still on vacation tomorrow and plan to finish the work then. So far I have about four hours in the job. I took several breaks and was forced to sit on my hands for about 45 minutes while I waited for a strong line of thunderstorms to pass, but I have to admit it was nice just to relax for a change and listen to the soothing sounds of wind, rain, and thunder.