If you frequent the 128i section of this forum, you may have noticed
another thread where I was talking about my problems with an uneven idle, some power loss at WOT, and persistent codes related to the eccentric shaft sensor. This is a fairly common issue with these engines, so it wasn't too surprising that I was facing it almost 7 1/2 years after my car's build date.
I ordered the parts a few weeks ago: a Genuine OE valve cover gasket set, Valvetronic motor gasket, and eccentric shaft sensor gasket (later I also ordered an oil filler cap gasket, based on the appearance of the original). For the eccentric shaft sensor itself, I decided to save a few bucks and go OEM and picked up a VDO unit. I'm nearly certain this is the same part as from the factory anyway. As long as I was going through all this trouble, I figured I'd do the spark plugs and coils, again going with OEM: Bosch for the coils and NGK for the plugs (literally the exact same part number on these).
There are a bunch of posts on various BMW forums about this job, so I won't go into too much detail, except to say
wow, what a pain in the ass. It's not technically difficult, but
- there is SO much stuff that has to come off before you get to the valve cover, and
- some of it is so damn finicky, so just take your time and don't break anything.
Finally, if you recognize this:
then you know the
massive ordeal that is valve cover removal on these cars. You will swear, cry, and moan before you get to the picture above. A few more tips:
- Don't take any short cuts - all those things you think maybe don't have to be removed or disconnected for access? They do (and then there still won't be enough room!).
- This has been said somewhere before, but make sure you have a good collection of sockets, including extensions and u-joints - you will not get this job done without them. You need a good E-torx set (E18 for the cross brace, E10 for the valve cover). I've been working slowly and deliberately over the course of several days - been busy with work and family obligations, plus I spent all day Saturday doing paint correction on the Mercedes - but a couple times I've been slowed down waiting for tools (like a deep 10mm socket - my deep sockets started at 12mm).
- Speaking of tools, it might be wise to have an inch-lb torque wrench around - the valve cover bolts are torqued at less than 10 ft-lbs, which is less than most typical torque wrenches can handle.
- I still have the car up on four jack stands from when I did the differential drain and fill - I'm not entirely sure it would be worth the effort to raise up the car for this job alone, but my back has enjoyed not having to hunch down so much all the time.
- If you're going to do spark plugs, it's worth picking up this special BMW tool in order to easily hand thread the new plugs before tightening then down with your torque wrench.
Anyway, that's all I can think of off the top of my head at the moment. I still have some ways to go before finishing - after snapping the pic above, I R&Red the faulty eccentric shaft sensor, as well as swapped out the spark plugs. You might notice in the lower right a new sport air filter - the original was installed almost 36,000 miles ago, and I'd rather just replace it than clean it.
Not pictured is the valve cover, which was hosed down and allowed to dry overnight, before I pressed in the new gaskets. I didn't get a chance to refit the valve cover today, but hopefully tomorrow, and my inch-lb torque wrench should be here the following day - right now the plan is to have everything buttoned up and back together before the end of the week.