N62 engine differences between X5 and 750i

[Cody4130]

I wanted to share my experience replacing the 4.8l N62 engine in my 2008 X5.
I'm new to this forum and hope to contribute useful things. If this has been covered before I apologize but I could not find it.

Backstory:
I bought my car as a non runner with 127k and was told the head gaskets needed replaced. I'm an experienced home mechanic so I figured no problem. In my area no local mechanics want to work on vehicles like this, so a loaded sport package X5 for a very cheap price was too tempting to pass up ...once I got the vehicle towed home I noticed the block had a hole from one side to the other right behind the motor mounts so I couldn't see it prior to disassembly.

Time for a new motor...no big deal right? I don't have a lift in my garage so pulling the motor out from the top was very difficult. If you have a way of getting enough clearance under your X5 to drop the entire subframe out the bottom it will save you hours of cursing. But alas I only had 24 of the 32 required inches (by my measurements)

After searching the internet I noticed that 5, 6 and 7 series engines were significantly cheaper than X5 engines about 1/3 the price. Found a nice looking 750i engine with about 120k for $800 and jumped on the deal.

Immediately I knew the oil pan would be different but since I had the complete x5 engine already (albeit with a hole in each side of the block) I figured any differences would be easily accounted for. I already ordered a full gasket set and all the special tools to set the timing and do valve stem seals. I knew I would have to do them when I bought the vehicle.

I began disassembly of my X5 engine while I waited on the 750 engine to arrive. Unfortunately as soon as I pulled the X5 oil pan I hit a snag. A rod had gone through the upper oil pan and also damaged the oil pump beyond repair. The inside of the engine looked like someone had dumped gravel in it, with rods, pistons and other internal parts were strewn about. I ordered a used X5 oil pan and it arrived when my 750 engine did.

I tore down the 750 engine to the short block. IMO this is a must on a 13 year old boneyard motor no matter the mileage.


Differences:
I'll get to the "long block" differences I came across now. This is by no means an exhaustive list or part number comparison. I used a 7 series N62. I would assume 5 and 6 series N62 engines have similar differences as none of them were AWD during N62 production years.

These parts cannot be "modified to fit" they are X5 specific.

1. Oil pan (X5 has the CV shaft run through the pan)
2. Oil pump (uses different bolts and is a different height/shape)
3. Dip stick

4. Lower timing cover and all associated gaskets, brackets, and harmonic balancer.

5. Left (driver side in US) upper timing cover and gasket. There is a bolt hole for the alternator that must be drilled and tapped into the cylinder head (M10x1.5 bolt) the 750 head has the boss cast it simply needs tapped. Be careful with drill depth.

6. The oil cooler lines. The 750 has a large bracket holding these lines that must be removed. The much smaller X5 bracket uses different mounting points that aren't drilled or tapped on the 750 block. It's obvious where they go. Just use the one bolt that does line up to secure the oil cooler lines and then drill and tap the two holes (M8x1.25). Again be very careful with drill depth.

7. Exhaust manifolds


I'm still in progress and may add more.

My 750 engine did not come with any accessories, wiring, or intake manifold so I can't comment on their compatability.

I used a $20 C clamp style valve spring compressor from amazon that worked like a charm with the head off. No need to spend more on a fancier tool unless you want to roll the dice and do the job with the heads on. My Elring gasket set came with new valve stem seals.

One other thing to note is the Mahle cylinder head bolts do not come with washers so make sure you keep the old washers.

Hope this info helps anyone needing to repower their N62 E70.