Replacing VANOS solenoid valves woke up my N62!

[electricalserv x5]

Originally Posted by fishhouse4

I'm not entirely sure what the VANOS solenoid valves do exactly...but I replaced all 4 on my 4.8is N62 as part of some recent upgrades (also did new NGK Iridium IX plugs, ignition coils and serpentine belt earlier in the day).

To my surprise the new VANOS solenoids had an awesome improvement to my engine responsiveness. Best way to describe it is that it's SOOO much more smooth now.

Previously I had a lag or delay after giving it gas (either light or WOT). After applying throttle it would just think about it for a second but then suddenly kick it and jerk your head. Now it's accelerating evenly and more quickly like I always expected it to. Seems more "peppy" on the butt dyno.

Am I going crazy?

sorry they do...……..it's like a new x5 NOW right......AWESOME

[andrewwynn]

Originally Posted by fishhouse4;

School me...how does the solenoid work exactly? Guessing it gets input from the wiring harness on the front (the part that sticks out)...but oil runs through the other end that is inside? For what purpose...like what does the solenoid do specifically to make all this fancy VVT function.

A little bit of educated guess here because the solinoids are on/off as far as I can tell and the vanos is analog:

I am pretty sure the solinoids get a pwm signal to send a metered amount of oil pressure to the vanos. Internal to the vanos there are a set of internal helical gears that mesh in such a way that as oil pressure is applied it changes the relative angle between the input and output teeth.

The cam position sensors feedback where the cams are and the solinoids get more or less signal to advance or retard the cams to match the program for the current speed and load.

[andrewwynn]

Originally Posted by oldskewel;

just rebuilt (seals and rattle rings)

Rattle rings? Are those the sets of "recatarings" that seal the oil distribution units?

[oldskewel]

Originally Posted by andrewwynn

Rattle rings? Are those the sets of "recatarings" that seal the oil distribution units?

They're called rattle rings because they fix a problem that causes a rattling noise in the VANOS.

In each VANOS piston, there is a Steel ring with about a 7mm square cross section, about 35mm diameter. Over time, the moving parts within this ring (needle bearing discs and washers) wear slightly, allowing for some extra slop which makes noise and somehow interferes with the timing adjustment. So the fix is to swap those "rattle rings" with ones that are slightly thinner. On mine, the new ones were 0.12 mm thinner. This means that the needle bearings and washers in the middle are now loaded again, so they don't rattle around.

Also, on the question about how exactly does the VANOS change the timing ... there is probably tons of carefully considered info out there on the interwebs, but here's my take from looking at the system recently:

The solenoids meter oil pressure to each of the VANOS actuators - one on each camshaft. So somehow the solenoid lets in the right amount of oil (at system oil pressure) to cause the VANOS pistons to move to the desired position - the pistons are aligned with the camshafts.

Each of those pistons move a little cup thing with TWO sets of helical splines - one on the inside of the cup, one on the outside, and since the two sets are rotating in opposite directions, when the piston moves in or out, it causes a rotational displacement between the pulley (connected to the outer helical splines) and the camshaft (connected to the inner helical splines). So mechanically, that's how the system can get whatever timing shift it wants, continuously.

The primary timing chain runs from the crank chain pulley, rigidly attached to the crankshaft ... to the exhaust camshaft's timing chain pulley ... then the exhaust VANOS makes its angular offset adjustment vs. the exhaust camshaft. The exhaust camshaft also has a secondary chain that drives the intake camshaft timing chain pulley. There, the intake VANOS dials in whatever timing adjustment it wants between that pulley and the intake camshaft.

So this way, in summary, those solenoids control oil flow to the VANOS. The VANOS moves its pistons, which move those double helical cups, which cause the camshafts to adjust their angle with respect to the pulleys. Continuously variable, independent on intake and exhaust. Pretty effin' amazing to see it all there and knowing it works so well.

[fishhouse4]

Originally Posted by andrewwynn

I am pretty sure the solinoids get a pwm signal to send a metered amount of oil pressure to the vanos. Internal to the vanos there are a set of internal helical gears that mesh in such a way that as oil pressure is applied it changes the relative angle between the input and output teeth.

Originally Posted by oldskewel

So this way, in summary, those solenoids control oil flow to the VANOS. The VANOS moves its pistons, which move those double helical cups, which cause the camshafts to adjust their angle with respect to the pulleys. Continuously variable, independent on intake and exhaust. Pretty effin' amazing to see it all there and knowing it works so well.

Exactly what I was wondering...thanks for the education.

[dadysev]

Originally Posted by fishhouse4

I'm not entirely sure what the VANOS solenoid valves do exactly...but I replaced all 4 on my 4.8is N62 as part of some recent upgrades (also did new NGK Iridium IX plugs, ignition coils and serpentine belt earlier in the day).

To my surprise the new VANOS solenoids had an awesome improvement to my engine responsiveness. Best way to describe it is that it's SOOO much more smooth now.

Previously I had a lag or delay after giving it gas (either light or WOT). After applying throttle it would just think about it for a second but then suddenly kick it and jerk your head. Now it's accelerating evenly and more quickly like I always expected it to. Seems more "peppy" on the butt dyno.

Am I going crazy?

Thanks!! I'm facing the same issue on my E70. I think it may be the inner O-rings on the solenoids as the seal up the oil from the inner timing cover to the vanes chamber that goes up to the actual vanos on the cam. No faults or anything. Sometimes at low rpm, if i just tap the throttle at little to accelerate 5km faster i hear a slight ping/knock also. Almost feels like out of timing slightly= Vanos!!

Failing that i will probably just replace the solenoids that come with new orings anyways, but for now this is a 20$ fix.

[dadysev]

Originally Posted by oldskewel

They're called rattle rings because they fix a problem that causes a rattling noise in the VANOS.

In each VANOS piston, there is a Steel ring with about a 7mm square cross section, about 35mm diameter. Over time, the moving parts within this ring (needle bearing discs and washers) wear slightly, allowing for some extra slop which makes noise and somehow interferes with the timing adjustment. So the fix is to swap those "rattle rings" with ones that are slightly thinner. On mine, the new ones were 0.12 mm thinner. This means that the needle bearings and washers in the middle are now loaded again, so they don't rattle around.

Also, on the question about how exactly does the VANOS change the timing ... there is probably tons of carefully considered info out there on the interwebs, but here's my take from looking at the system recently:

The solenoids meter oil pressure to each of the VANOS actuators - one on each camshaft. So somehow the solenoid lets in the right amount of oil (at system oil pressure) to cause the VANOS pistons to move to the desired position - the pistons are aligned with the camshafts.

Each of those pistons move a little cup thing with TWO sets of helical splines - one on the inside of the cup, one on the outside, and since the two sets are rotating in opposite directions, when the piston moves in or out, it causes a rotational displacement between the pulley (connected to the outer helical splines) and the camshaft (connected to the inner helical splines). So mechanically, that's how the system can get whatever timing shift it wants, continuously.

The primary timing chain runs from the crank chain pulley, rigidly attached to the crankshaft ... to the exhaust camshaft's timing chain pulley ... then the exhaust VANOS makes its angular offset adjustment vs. the exhaust camshaft. The exhaust camshaft also has a secondary chain that drives the intake camshaft timing chain pulley. There, the intake VANOS dials in whatever timing adjustment it wants between that pulley and the intake camshaft.

So this way, in summary, those solenoids control oil flow to the VANOS. The VANOS moves its pistons, which move those double helical cups, which cause the camshafts to adjust their angle with respect to the pulleys. Continuously variable, independent on intake and exhaust. Pretty effin' amazing to see it all there and knowing it works so well.

Rebuilt those from Besian systems on my e53 3.0. What a huge difference on low end power!
I did one on a friends E60 530i also. It was the first time he's heard the car leave a patch of rubber behind! lol.

[ajacks8]

My two questions are, what is the estimated time for replacement on the N62? AND, which of these do I need to accompany the solenoids? 11367513222 and/or 11367546379? Thank you for any insight.

[dadysev]

Originally Posted by ajacks8

My two questions are, what is the estimated time for replacement on the N62? AND, which of these do I need to accompany the solenoids? 11367513222 and/or 11367546379? Thank you for any insight.

Just did all 4 of mine on my N62. Took me half hour. Need 4 of each. Good time to clean up the little screens on the solenoids. I found some filter material on mine !!

Going to take it for a test run in half hour

[ajacks8]

Originally Posted by dadysev

Just did all 4 of mine on my N62. Took me half hour. Need 4 of each. Good time to clean up the little screens on the solenoids. I found some filter material on mine !!

Going to take it for a test run in half hour

Thanks! Do you need both sets of O-Rings, or just 4 of the larger. It looks like NEW genuine solenoids already come with the smaller one attached. Also, I scored 4 solenoids (pn #11367560462) for $120.99 apiece. I pulled the trigger on 4 after trying to get a few other vendors to price-match. I soon learned that this was less than cost, so I could not resist purchasing. Right after I hit submit order, they were jumped back up to $167.99. Interesting, right??? RealOEM shoes $118.xx...a little hard to figure why. Anyway, hopefully I only need the larger O-Ring for replacing with new solenoids. Thanks.