The X5 is running strong and (knock on wood) has been a reliable daily driver again. I've got a plenty of "nice to have" stuff I still need to do to it, including trying a 90deg MAP t-stat, reupholstered seats that need to be installed finally and a blower motor R&R that will be nice, once the job is done! No hurry on this last one since it is OK when its warm out but screeches like a cat when the temp drops.
So I finally had some time and energy to begin tearing down the M62TUB44 I took out of the X5 today. Initially I'm interested in seeing if the bores looked good, or were scored. Thankfully my untrained eye tells me that they look good. I've got what look like wear on the walls where the (skirts maybe?) have made 150k miles worth of contact, but other than a slight discoloration, I can't feel a thin with my fingers or nails. I've seen some pics of scored bores on this and other boards, and thankfully I think I missed this problem, which will allow me to proceed with a rebuild. My plan was simply to scrap the motor if a bore(s) were trashed.
The motor has been sitting for close to 2 years now (time flies) and was a terrible greasy lump when I wheeled it into the corner of the shop after the swap was complete. I preparation I watched a couple videos on timing chain and head gasket R & R, and figured I'd take lots of pics, bag all the small parts, and see how it went. This will be my first motor rebuild (assuming I don't find any show-stoppers), but the teardown went very quickly.
From this:
To this in a couple hours:
I pulled the accessories first and while I had already robbed the AC compressor and accessory tensioner for the new motor, I tossed the power steering and water pumps, and hung onto the balancer, pump pulleys, and rear manifold and coolant pipes. I was pleasantly surprised at how clean the coolant passages were.
Next I pulled the valve covers, pried out the vanos seals out, and pulled the front timing covers. The covers are a mess and I'll need to evaluate if they can be salvaged. I've already noticed the covers on my new motor are beginning to "bubble" in a few small spots too. Not sure if this is the magnesium, or paint, or what?
Then I pulled the chain tensioner and got enough slack to work the chain off, which is good because I need to buy a socket big enough for the VANOS solenoids. I did first loosen the large nuts on the intake cams thinking the sprockets would slide off and I could get the chain off that way. Fortunately enought he tensioner removal created plenty of slack. The bottom cover is still on, but the parts of the guides I can see look to be in amazing shape considering the car had 160k on it, and i never changed the tensioner. Nor, for the 5 years my kids were driving it was I all that great about changing oil at my normal 4 to 5k interval.
After this work was done it was quick work to zip the head bolts out and pull the heads. Again, not sure what I'm looking at, but the valve train seems very clean while the combustion chambers, like the piston tops, have a lot of carbon build up on them.
As an aside, the block still had a lot of antifreeze in it (green, I'm ashamed to say!), so at this point I pulled the plugs on the either side of the block and drained it all.
Next up I inspected the head gaskets for signs of leaks, blowby, etc., and they looked good so I turned the motor over and looked in each cylinder. Happily they all looked great, to my untrained eye. As I said, I've seen pics of alusil motors with bore scoring, especially the M62 woes in this respect, but they look good to me.
Below is an example of what each cylinder looks like. I've circled the discoloration (slightly blue, maybe?) that is in each one, often on opposite sides of the cylinder, but where I can not detect any variance in feel with my finger or fingernail. All the pistons, and combustion chambers look like this one....lots of carbon build up.
So I'm going to call this a win and plan on rebuilding this motor to put into something fun eventually. I'm still noodling just what sort of rebuild to do (M60B44, or just stock), so more to follow on that. Frankly, I've not had too much luck finding M60 heads that aren't cracked, etc. either so maybe I'll just rebuild a stock M62TUB44.
This project will be a slow burn, so I'll likely just tack it onto my X5 overland thread, if anyone is interested at all. Next up is to buy a vanos socket so I can pull those solenoids and a crank hub tool to hold the thing so I can try to get that monster bolt off.