Official X5 4.6is & 4.8is Thread

[retcav1sg]

[retcav1sg]

I found it...Touren wheels

[Henn28]

Gents, hoping to get a parts check from the 4.6 motor brain-trust. What I'm calling my "4.6i" threw the accessory belt just when I was really starting to trust her, after 1100 miles on the new motor. I've got the car at a local indy for a deep dive, since my money is on a mistake I made causing the belt to come apart. He's also doing a rear axle because I think I'll have a stroke if I need to do another axle any time soon.

At any rate, can you guys confirm if you have, or don't have the small idler pulley attached to the power steering pump? The part number for the pulley is 11287500560, and RealOEM refers to it as a "deflection pulley". I didn't have this on my 4.4 when I pulled it, so I didn't build my 4.6 with it. However, I lost the belt and am now wondering I screwed this up. I will say that the indy working on my X5 has owned and built several 540 based projects over the years and has seen this pulley on the 540. However, it was such a pain in the butt he said that on one of them he deleted it and drove the car with no problems for years. Neither he nor I can determine which, if any X5s have it. RealOEM refers to "automatic transmission" cars, but its anyone's guess if autos have, or don't have this pulley.

Assuming that it's not as simple as me not tensioning the thing right (could have happened, but it is pretty straight forward), the other option is that the complete accessory drive refresh kit I bought had the wrong belt included. The 4.6 belt is a different size than the 4.4 due to the harmonic balancer being a slightly different diameter.

On another note, I'm looking at a zionsville all-aluminum E53 replacement radiator for my car to replace the factory piece that was spewing old-faithful style from where the plastic meets the aluminium, at the upper hose region. Lots of money, but they are beautiful and what price peace of mind!? An electric fan swap for the oem clutch system too sounds pretty nice.

Thanks all - Brian

[AV8R4AA]

Does anyone here know what, if any differences the harmonic balancer
is between the M62 4.4 and the 4.6. I’m driving a 4.6.
Asking because mine has a slight wobble and would like
to replace it with better pulley.
New is 500+

[bcredliner]

Not sure. Compare part numbers at www.realoem.com

[740ilDuke]

Did you look them both up on realoem.com ?

[bcredliner]

Originally Posted by 740ilDuke

Did you look them both up on realoem.com ?

I didn't look them up. Suggesting that is where to find out if they are different by looking up both part numbers.

[AV8R4AA]

They are different part numbers. Very close to same engine, yet different pulley

[Henn28]

Originally Posted by AV8R4AA

Does anyone here know what, if any differences the harmonic balancer
is between the M62 4.4 and the 4.6. I’m driving a 4.6.
Asking because mine has a slight wobble and would like
to replace it with better pulley.
New is 500+

I’ve had them both in my hand, recently. I ended up getting a new 4.6 balancer for my motor build…three actually since the first two arrived damaged from BMW. The 4.4 and 4.6 cranks are different, ergo, different balancers. The 4.6 has 6 dimples drilled into its lip while the 4.4 had fewer. Three or four, I seem to recall. These extra dimples I guess serve some purpose in balancing the 4.6 crank. The 4.6 balancer is also an under drive piece which extracts a bit more power out of the motor by running the accessories slightly slower. Not critical, but I think the different number of balancing dimples are probably reason not to sub the 4.4 balancer. Although I suppose the dimples could also serve to balance the actual balancer. Although it is a pretty precisely machined pice of metal.

As you mention, they (4.6 pieces) are close to impossible to find used. I also looked for an after market from ATI, but they wouldn’t build one for me. They said all their BMW pulley/balancer orders go thru VAC, who told me “no” when I asked if they could make a 4.6 balancer.

Getbmwparts.com had a pretty good discount on it, and took the first two back with no questions when they both showed up damaged.

[AV8R4AA]

I always assumed the dimples are “lightening” holes.
I’m talking weight and mass, not thunderstorms.
Both of the crank flange ARE the same part number.
I would presume that they would bolt up the same.
If the diameter is different than I am at a loss.

My goal is to keep the old redhead on the road. Not break the bank.
I have not checked yet, but a different diameter should require a different belt.


JUST CHECKED
Different serpentine belt part numbers.
Guess I need a new balancer.