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.

[ard]

Thanks for posting!

What month/year was the old and donor motors? Just in case someone wonders in 4 years...


Im a diesel guy, but appreciate the guts.

[andrewwynn]

That's some great info. What displacement? 4.8 in your signature is it the same?

[Henn28]

This is a great thread to start, especially from an experienced mechanic. I am much more an amateur, but have been working to get up to speed on M62 differences as my 4.4 is on its way out compression-wise. My sense so far is that they are confined to the oil pan and pump, and (related) CCV plumbing in the M62 series.

One very frustrating aspect of this fact was learning that the oil pump chain is behind the timing chain on the crank. I found a nicely refreshed M62 originally from a 4.6 X5 but which had been converted to RWD, however the oil chain position meant that the whole front end had to come off the motor again, and the timing would probably need to be revisited. E53 upper pans and pumps/pickups are readily available on eBay, but what should be a relatively easy job is actually much more difficult due to the chain position. No on makes a removable link chain either, that I could find.

Beyond the oil pan set-up however, I think the M62 motors are identical from the block up. There is a very good chance though that I have missed some detail(s).

[Cody4130]

Originally Posted by andrewwynn

That's some great info. What displacement? 4.8 in your signature is it the same?

Thanks.
Yes this is for the 4.8l engine.

[Cody4130]

Originally Posted by Henn28

Beyond the oil pan set-up however, I think the M62 motors are identical from the block up. There is a very good chance though that I have missed some detail(s).

Although I have not worked on the 4.4 I believe there are significant differences from the 4.8. Seems most of the gaskets and items I have ordered have different part numbers from the E53 4.4 to E70 4.8.

[Cody4130]

Another difference I've noticed is a rectangular nub cast into the block on the left side where the front diff mounts. The nub is right where the oil pan meets the block and must be ground flush for the diff to mount properly. There is also a dowel pin in a hole that isn't used on the X5 that needs removed before the front diff will seat fully. There are two dowel pins but only the lower one needs removed.

[Cody4130]

Last major difference I found the hard way. The right side rear most cylinder (#4) has the studs tapped in the opposite locations. You will need to remove the studs from your 650/750 heads and then drill and tap holes for them in the X5 pattern. This is not a big issue as all the other cylinders are in the same place.

This engine is now in and running well in my X5!!

I will post pictures whenever I figure out how to resize them from my iPhone. The site currently says they are too large to post.

[andrewwynn]

Use tapatalk it resizes automatically also finally after a dozen updates will do more than one photo at a time


Sent from my iPhone using Tapatalk Pro

[snowdouble0]

I want to add that this post was super helpful and bought me to this forum after I picked up an e53 with only 7 pistons.

I completed an engine swap, with a n62 4.4 from a 645 to my x5 e53 2004 4.4. The old engine had died, and the swap was rather straightforward, involving all the swap detailed here.

The one thing that was different in my case was the exhaust manifold studs on one side were of the 645 block were the diagonal opposite to the original. This was solved by drilling and threading studs for the exhaust manikin to the correct locations.

Originally Posted by 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.