Sunday, February 4, 2007

1/27/2007, 159342 miles: Timing Belt, Water Pump

It pays to read.
There's plenty of resources out there on doing the timing belt service, and I got them all. Picked up the Bentley, the really good book from Pelican, a Haynes (useless, not worth it), and a Chilton (same one I was using for the M5). I also read and re-read the write-up on E34.net and on E30.net.

Parts arrived earlier that week, and with the missing tools bought that morning, I felt I was ready. With the hood removed, it was pretty easy to get at everything. I was working slow, and got off to a really late start (12:30ish) so it took almost 5 hours to finally get the belts and crank pulley off. The biggest hassle of all was the radiator fluid...I'll never understand why engineers can't design the engine block drain to make less of a mess. This is the third car I've done the block drain, and it's the same result: fluid EVERYWHERE. So I spent a chunk of time cleaning up the floor on the (borrowed) garage.

One other hitch was the accessory drive belts (power steering, alternator, A/C). I was rushing things a bit and forced the toothed adjuster nut, ended up stripping the teeth on the mounting bracket for the power steering pump (doh!). You're supposed to loosen all the bolts first and then loosen the adjusting nut. So now I gotta order a new bracket (was able to tighten the belt OK, though).

I've been working on Nissans so much, I got really used to the socket sizes...the most common ones are 10mm, 14mm and 17mm. But on the German car, I spent SO MUCH time relearning the different sizes. Turns out they like to use a lot of 13mm nuts/bolts. That took a while to get used to, reaching 3 or 4 times for different sockets and wrenches.

Other frustrating thing is I didn't read closely enough. To remove the camshaft sprocket, you need a T-50 torx SOCKET, not the bit. I wasted at least 90 minutes trying to find this special socket (really tough to do on a Saturday night). So instead of delaying the project any further, I decided to postpone replacing the camshaft seals (damnit) until the next timing belt change. Hopefully, not too much oil is leaking out of that area.

All in all, with a 2 hour dinner break, I ended up calling it quits at midnight, with the motor pretty much wrapped up, leaving only the coolant fill & bleed the next morning. It was waaaaay too late to be firing up a loud ass 2.5L with no cat.

Came in the next morning to fill the coolant, bleed, and reattach the hood. All was well.

Except I didn't read how much coolant the system held (11 quarts). And I only bought 1 gallon of BMW antifreeze. For a 50/50 mix with distilled water, that leaves me 3 quarts short of full. Doh!!! So the mix is actually more water than antifreeze, but it should be OK in this climate.

It sure was a nerve-wracking moment preparing to turn that key! My mind raced through the checklist: any bolts missing? Timing checked and rechecked? It was definitely a relief to hear that motor spring to life with a roar. (And a slight squeal of a fan belt - damnit - I'll get to that next time)

Next up, valve cover gasket and ignition (distributor, rotor, coil, plugs, wires). And after that, the go-fast suspension goodies, then tires, then LSD, then new seats.... oh, the fun never ends!