alternator busted and VANOS

Well, my alternator is busted and is now not producing much juice (test #9 shows 10.6V when idling).

I plan to change it this Saturday, and since I'll have the fan and fan shroud out to have more elbow room anyway, I want to just man up and do the VANOS procedure too! Very excited indeed. Is there anything else I might as well get done in there?

Thanks!

The VANOS solenoids apparently have O-ring seals; replace them.

How many miles on your last cooling system overhaul? Never done? S/b at least 90k for all components.

+1, cooling system is more important than the Vanos, even though it results in zero net difference in performance. It only ensure survival of your engine.

You don't need to remove the fan and shroud to replace the alternator. BUT if you havent done the cooling system then you might as well if you have those items removed. I had to remove the alternator when I replaced my oil filter housing gasket. Before that I replaced the hoses from the power steering reservoir.

Of course if you are going after the vanos seals, replace the valve cover gasket & spark plug seals. The valve cover gasket may be plasticized and welded to the top of the cylinder head, necessitating slow, careful prying and separation with appropriate tools (putty knife etc); flex the plastic cover too much and it may crack.

Be sure to have a small torque wrench that's designed for very light torque specs and that's accurate in either direction.... The vanos piston bolts are reverse-threaded (turn CW to loosen) and will take only 6-7 ft.lb of torque.

edjack mentioned replacing the vanos solenoid O-rings. That's a job you can always do separately at a later date if they give you problems, but it should be much easier to remove the solenoids when the vanos unit is off the car.

This is also the perfect time to refresh the entire cooling system with new parts because you have to remove the fan shroud and expansion tank to have good access to the vanos unit.

Oh yeah .... about your alternator. It's possible to replace the regulator unit without removing the alt from the car. If the bearings in the alt are not shot, the fault is almost certainly the regulator. Of course, it never hurts to have a spare alt on the shelf, so don't throw the broken alt away. Someday you may want to try and refurbish it.

That alt might not be all that bad--could be the voltage regulator gone bad--reg has three screws that hold it to the back of the alt--would run you under 50 bucks and you wouldn't have to remove the alt to make the fix--

Originally Posted by poolman

That alt might not be all that bad--could be the voltage regulator gone bad--reg has three screws that hold it to the back of the alt--would run you under 50 bucks and you wouldn't have to remove the alt to make the fix--

Where's the source for good quality under $50 voltage regulators? IIRC, usually closer to $100.

I snagged mine from Bimmerspecialist for 48 bux, a tad more than Autohaus or ECS, where they are ariund 40. Shipping to Canada was the killer.

Originally Posted by doru

I snagged mine from Bimmerspecialist for 48 bux, a tad more than Autohaus or ECS, where they are ariund 40. Shipping to Canada was the killer.

Thanks. My bad. Air cooled VR cost alot more than water cooled VR.

Thanks, Guys!

I did my cooling overhaul last year and never looked back.

The regulator thing is interesting, but well, I already bought a re-manufactured alternator.

The refurbishing the old one idea in a future date is really nice, made me feel less bad that I already bought another alternator. Thanks!