Picked up a seized engine E70 (N55)

[BergA]

Hi all,

Last week I stumbled upon a pretty clean 2012 E70 35i with a seized N55 engine (73k miles). I recently rebuilt an N54 engine in a 335xi, so this project shouldn't be too different. I don't have a smoking gun as to what caused the failure, but most likely a low oil condition.

Today I worked on it for the first time. Today's goals were:
-Understand the "Vehicle may not go into Park" error message on the iDrive screen
-See whether engine can crank over, as it will be required to disconnect torque converter
-Remove drive axles (they will need to be removed before engine can be pulled)

1. The vehicle displays an error on the screen about not being able to go into Park. Not wanting to have to buy a transmission for this thing, I needed to understand what's causing it. The PO said the tow truck driver created the error by crawling under the car and "doing something" prior to towing it. Turns out, there's no way to put the car in Neutral when the engine won't start. So BMW has built in an override lever to force the tranny into neutral. To do this, you screw-in a socket head cap screw on the passenger side of the transmission all the way. Details here: http://www.bimmerfest.com/forums/att...1&d=1341253633

2. To crank the engine, I needed to clear out some stuff in the engine bay. First came the raw aluminum tube-strut with 4 bolts and the power steering lines attached to it. Then the radiator slid directly upwards and out. From there, I used a breaker bar and 22mm socket to crank the engine over. It was stuck at first, but then "freed" up. I put that in quotes because it still took ~100ft-lb to crank the engine.

3. The real project of the day was removing drive axles. I didn't take many pictures, but here is the vague sequence of events:
a) Remove front wheels
b) Remove drive axle nuts with 36mm 12-point socket and impact gun
c) Press drive axles through hub. I used a cheap harbor freight 3-jaw puller around the brake disk. I loaded the puller gently, then hammered on the press pin with a steel hammer. The shafts moved out fairly easily so I doubt I subjected the disks to much stress.
4. Unbolt the brake calipers from the hub with 2x E18 (?) bolts and zip tie it out of the way.
5. Remove the nut at the top A-arm. Then tap the bolt out. At this point spring pressure should automatically separate the joint, otherwise tap it with a mallet.
6. Remove the cast "fork" that attaches to the bottom of the shock. There is one pinch bolt holding it onto the fork, and then a pivot bolt at the bottom holding it onto the bottom control arm.
7. At this point, the hub is flexible enough to get the drive axles out.
8. Get under the car and pry the drive axles out. This was really tough. Just pry with everything you've got and keep your force axial. Don't try to use the drive axle as a slide hammer; it won't work.

[RIHI]

Nice project. Good luck.

[BergA]

Today I continued clearing out the engine bay, preparing for engine removal. The N55 makes the wiring harness significantly simpler than the N54; the engine computer is mounted right to the intake manifold, and the harness plugs into the computer with 6 large connectors.

During disassembly I found a few components already broken, several screws not tight, and a few wires not properly routed. Someone has definitely already been inside, and someone with not-so-great craftsmanship.

Moving forward, I have a few questions I need to resolve before the engine can come out:
-What to do with the power steering pump? Leave it on the engine or remove? There is almost no access to it, although this is how I did it on the N54 project.
-What to do with the power steering rack? It leaves only about an inch of space for the engine to move forward before the oil pan interferes. The more I think about it, the more I think I'll have to remove the subframe directly before the engine comes out. It would simplify things.
-What to do with the heat exchanger behind the radiator? It looks like it's cooling the transmission lines, which inconveniently run from that front heat exchanger all the way through the transfer cases and into the transmission. They will be in the way the entire time.

[ard]

Subscribed. Interested to hear the cause and extent of damage. "Low Oil"... hard to understand how that happens.

GL!

[Ozer]

Nice, looks like you know what you're doing. How is the carbon buildup in the intake ports at 75k miles?
I haven't read any threads on here where someone pulled out the engine so hopefully you get answers to your questions.

[Pierce330]

Originally Posted by ard

Subscribed. Interested to hear the cause and extent of damage. "Low Oil"... hard to understand how that happens.

GL!

Was just about to ask what caused the seizure? Looking forward to seeing reading about the process.

[Aquamania]

Man this is a great project. Good looking rig there!!! I will be watching your progress on this. You obviously know your way around that vehicle!!!

[noelskii]

Do mind telling us how much this pick up was?

[BergA]

The intake valves were not as dirty as the N54 I rebuilt. That one has 20k more miles but had significantly thicker sludge. Makes me wonder if this one had been walnut blasted recently?

I picked up the car for $14k. I'll leave it for you to decide whether it was a good deal or not.

Regarding engine removal: the more I think about it, the more I think it makes sense to drop the subframe at the same time as the engine comes out. Since the engine would be supported by an engine hoist, the subframe would be unloaded. This step would have the following benefits:
a) power steering rack could hang lower or go more forward, allowing an easier path for the engine to move
b) The oil pan-mounted transfer case could be removed, thus un-entraping the transmission cooler lines
c) I'd have easier access to unbolt the power steering pump
d) I'd have more space for the downpipe/catalytic converter during engine removal

[Aquamania]

Serious issues with those valves. Looks like piss poor maintenance to me.