It's the brittle issue that I'm more worried about - almost a silent killer.

Lot's of horror stories of them failing at 90k+ over in the UK with zero warning.

Here are my $.02 cents when it comes to M62 engines. In all of my M62 equipped BMWs when even ever I got to the point of resealing the timing covers I have always gone in and replaced the guides and chain for future piece of mind. My X5 started to exhibit a whirring sound at 99K miles and I thought it was one of the tensioners or bearings on the alternator, ac compressor and come to find out it was the beginning of guide failure. I like to have piece of mind that where ever I drive my BMWs they are mechanically sound. I could have gone a few more thousands of miles before changing them but I was already half way in there. The guides are gonna fail and I much rather be proactive then reactive to the situation when it occurs. This is a known concern with the M62 engines in the BMW X5.

I'm guessing it got thrown up there by the chain.

Exactly.

If everything is quite and proper otherwise then I wouldn't worry about it. The guides give you plenty of warning, you'd have to be super negligent to actually wreck your engine.

The horror stories are the minority, I'd say most M62tu's have a pretty good chance of going past 150k miles on original guides.

Yeah, that's how I ended up doing the guides on the Range Rover, I had the timing covers off and decided to go all the way. If you're comfortable doing your own work then it's pretty easy to take care of the guides, but if you have to budget like $3000+ for a shop then that certainly makes it a lot scarier.

I just placed a massive parts order from FCP Euro for all of the chain guide-related parts. It was quite the list, especially since I'm doing the valley pan as well. The total ended up being around $650 with shipping, thanks to some aggressive price-matching.

I'll definitely be doing the valley pan at the same time when I get round to doing it as I suspect I have a weep from that area.

I really can't tell if it's leaking but it looks absolutely FILTHY there, like I'm talking half an inch of grime. It's safe to say that the valley pan has never been touched, so I might as well replace it just in case. It's barely any extra work so it's worth doing.

The upper timing covers are covered in half an inch of grime as well... that should make disassembling the engine entertaining. Time to stock up on brake cleaner and degreasers.

And of course the day after I last posted I got sick and that threw me off for a few days, ugh. I was finally feeling better last night so I got some more work done.

The first thing I did was drain the cooling system so I could remove all the hoses. Thankfully on the X5 there's a proper drain plug in the radiator on the driver's side, but you have to remove the expansion tank cap up top or else practically nothing comes out. Once I drained a lot of the coolant out I was able to remove the expansion tank and all the cooling hoses. More coolant came out when I removed the lower radiator hose, and some came out of the alternator housing as well, so keep those drain pans handy!

Once the cooling hoses were removed, I proceeded to removing the clutch fan. I do own the proper tool for this, but a friend is borrowing it, so I had to remove it with the redneck method. I sprayed the fan clutch nut with PB blaster, let it sit for a little, and then put a 32mm wrench on the nut and whacked the wrench with the mallet until the nut came loose. It's not the most glamorous method, but it does work every time! With the fan removed, I was able to remove the fan shroud, which is only secured with three push rivets. This is what the engine looked like at this point:

https://c2.staticflickr.com/1/400/31...ccdf9da8_b.jpg

Look at the nasty gunk around the passenger side upper timing cover:

https://c7.staticflickr.com/1/774/31...f616a983_b.jpg

Yum.

https://c3.staticflickr.com/1/548/31...dabcdd1d_b.jpg

I removed the belts and continued the disassembly, moving on to removing the upper timing covers. I initially sprayed the timing covers down with brake cleaner so I could find the bolts in the sea of grime. The Vanos solenoid gaskets had a bunch of goopy black rubbery stuff around them, which makes me think somebody had messed with them before. The Vanos solenoids came out pretty easily with the proper socket tool. Once those were out, I undid the 6 bolts on each timing cover and removed the timing covers. Neither timing cover presented too much of an issue, and their gaskets were hard as a rock and practically disintegrated upon removal. Once the timing covers came off, that's when things got interesting...

The tensioner rail had been ground down quite a bit by the chain, indicating that the plastic had worn away a long time ago. There was no plastic at all on the U-guide.

https://c5.staticflickr.com/1/646/31...e3e09ab3_b.jpg

Over on the other side, the U-guide was missing all of its plastic as well.

https://c3.staticflickr.com/1/681/31...2843e99d_b.jpg

Curiously enough, the plastic guide on the driver's side looked pretty much intact.

https://c4.staticflickr.com/1/571/31...4b5ed2fe_b.jpg

I also found a few interesting pieces of plastic laying around...

https://c7.staticflickr.com/6/5551/3...c5398538_b.jpg

Looks like one of the guide pieces got caught somewhere particularly warm and started melting, how fascinating!

This is how the engine looked when I called it a night:

https://c1.staticflickr.com/1/643/31...37c39459_b.jpg

Next on the agenda is to disconnect the battery (which is annoyingly placed under the compressor in the trunk), remove the harmonic balancer, remove the water pump, remove the alternator, and then undo the big crank bolt (aka the Jesus bolt). Fun times ahead!

OMG! :wow: :wow: :wow:

You go Danny! :thumb up: :thumb up:

You are making this look easy!

Mike

nice progress, glad this 4.6 went to a proper owner. To another 200k!

More progress last night! I bought a new (to me) DSLR recently so I used that to take the pictures. Super fancy pics now.

I started by removing the crank pulley (aka harmonic balancer) and the water pump. Man were they dirty.

https://c5.staticflickr.com/1/723/30...9dd354d4_b.jpg

Surprisingly, the lower timing cover doesn't look all that bad:

https://c7.staticflickr.com/1/765/31...e1888604_b.jpg

After the water pump was removed, I removed both belt tensioners. One of them was being a little stubborn but it came off eventually. After that, I disconnected the battery to remove the alternator. I wonder who thought it would be a great idea to hide the battery in the X5 under the spare tire and air compressor... I also found a hacked-together U-Haul trailer wiring harness in the trunk, yay. The alternator came off pretty easily, though the bolts holding it down were unreasonably tight. Makes me wonder if somebody had monkeyed around there before.

With the alternator removed, I proceeded to remove the intake manifold to access the valley pan. Removing the intake manifold involved removing 10 11mm nuts, disconnecting the fuel line, and removing a bunch of hoses at the CCV in the rear. With everything disconnected the intake manifold came off pretty easily, revealing a nasty sight underneath.

https://c2.staticflickr.com/1/300/31...1747ea04_b.jpg

As I suspected, the valley pan is leaking a bit already:

https://c7.staticflickr.com/1/409/30...f5e943ce_b.jpg

https://c2.staticflickr.com/1/525/31...a2d4a7cd_b.jpg

I'm glad I ordered the parts to do the valley pan job, because I wasn't sure if the valley pan needed to be replaced. Thankfully I caught this leaking valley pan before it became a serious problem. I highly recommend checking on it when you do a chain guide job— the extra labor is minimal. Plus as a bonus I'll get to replace the water pipe o-rings at the back coolant manifold and I'll get to install fresh new intake manifold gaskets to eliminate the common rough idle upon cold startup.

The oil separator return hose pretty much crumbled apart when I removed the intake manifold... turns out the oil separator is still original with a 2002 date on it, and the return hose is still original since it has the annoying BMW factory clamps on both ends.

https://c6.staticflickr.com/1/444/31...5fc8c398_b.jpg

https://c1.staticflickr.com/1/613/31...93fc4b7d_b.jpg

I ordered a new return hose and a new oil separator from AutohausAZ this morning, since they're local to me and might have it available either today or tomorrow. I figured I'd replace the oil separator since it's original and easily accessible, because replacing it with the intake manifold installed does not sound fun at all. I also ordered new cam chains because the current ones have 213k miles on them. Once this engine is all fixed up I shouldn't have to mess with it for a very long time.

I bought some new GAS timing tools as well, since they're supposedly easier to use and less finicky than the BMW-style timing tools that I currently have. I love that the GAS cam lock blocks actually screw down instead of just floating on the camshafts like the BMW tools. The Beisan Systems vanos seal kit also showed up the other day, so I'll be able to rebuild the Vanos units for a rattle-free experience.