All in - pulling the 4.6 engine and trans to fix oil leaks once and for all

[kesslerbmw]

Btw....

Let me put out what I've gathered about the timing chain guides on these motors, and you tell me, or anyone else in the conversation tell me what they think.

From what I've read, the guides fail do to a weak tensioner. When the tensioner get week, the chains slap the guides and break them into pieces. Its not that the guides all the sudden fall apart.

So as long as you keep a good tensioner in the motor you shouldn't have to worry about the guides going bad.


Otherwise where you have this motor town down to, you'd be stupid not to replace them. Right?

[admranger]

Originally Posted by kesslerbmw

Otherwise where you have this motor town down to, you'd be stupid not to replace them. Right?

I wouldn't say stupid, but you'll be hating life if one breaks in the near future.

[kesslerbmw]

Originally Posted by admranger

I wouldn't say stupid, but you'll be hating life if one breaks in the near future.

But if its caused by a bad tensioner and you keep a good tensioner in it, why would it matter? Or is this theory wrong? If its right, even with brand new guides, they could still shatter/break with a bad tensioner.

Not trying to thread jack, just curious how the OP feels mainly.

[J.Belknap]

Originally Posted by kesslerbmw

From what I've read, the guides fail do to a weak tensioner. When the tensioner get week, the chains slap the guides and break them into pieces. Its not that the guides all the sudden fall apart.

So as long as you keep a good tensioner in the motor you shouldn't have to worry about the guides going bad.

No. Plastic ages while being heat cycled and gets brittle and will fall apart no matter what. Don't spread bad information.

Stunt. You're getting a new crank snout yes?

[stunt]

Originally Posted by J.Belknap

You're getting a new crank snout yes?

Crank snout? Are you referring to the crankshaft hub held on with the "Jesus" bolt that the balancer attaches to?

If so, what would be the reasoning behind replacing that piece?

[kesslerbmw]

Originally Posted by J.Belknap

No. Plastic ages while being heat cycled and gets brittle and will fall apart no matter what. Don't spread bad information.

Stunt. You're getting a new crank snout yes?

Was trying to have a discussion, not spread bad information. If you would have quoted the whole post you can have re-read what I said instead of taking only part of what I said.

There are motors well over 200k miles with original guides, and there's 100k mile motors that need guides... I'd like to figure out what makes them last longer, or way longer. What's the issue with that?

Why is it that M62's are the only ones with timing chain guide issues? These motors are the ONLY ones. I've had M/S50 style engines of all variants and displacements, with all types of miles, and I've had super high mileage M60's that have never had a single issue. Even cars I've tracked, and have been run through the ringer... Not a single issue with a timing chain guide. If your theory was 100% correct we'd be tearing down 3.0 X5's, and every BMW engine produced to put timing chain guides in. I'm trying to look at the issue deeper than saying... ohh, its plastic and it broke, there is more to it.

We know its a bad design, but what makes those 200k plus mile motors keep going on original guides to this day... Is it that they replaced the tensioner every 80k miles? Is it their oil type, and service intervals?

I've had my fair share of BMW's, and plan to continue to enjoy them, but it would be nice to figure out some type of plan that would keep from having to tear the guides out every other time the car is ready for an Inspection II.


Stunt- I've used the flywheel locking tool to remove the crank bolt a few times, works well in the car. I made my own tool to bolt to the crank when I've had a motor on a stand, but I don't have a flywheel on the motor while its on the stand either. I wouldn't suggest a sledge though, using a breaker bar, and the handle off of a floor jack has always worked well for me. The constant steady force will be easier on things that jolts of energy.

Badass tractor btw

[stunt]

Well, let me put it this way, I haven't ordered any parts yet. I wanted to wait until I have everything taken apart to determine what I need.

Interesting concept about the guides failing being a result of a bad tensioner. I will say I was surprised at how good the guides look. Once I get the lower timing cover off, I'll be able to inspect them more closely. But for piece of mind, I suspect I will end up replacing them.

[Junkycosmos]

+1 stunt on your efforts and thread here. Thank you for taking the time to share as your project goes. I am curious on which move you take with the TC guides too.

Junkycosmos
2005 4.8is @92k miles

[stunt]

I cleaned the valley sides this afternoon. What a pain that was using just towels, a pick tool, a little solvent and a shop vac. I didn't have the luxury of hosing down as I went being that the topside is now exposed and I was working indoors.

I was a bit surprised to find the valley full of coolant once I removed the cover, but I guess that was to be expected since I didn't remove the freeze plug in the block.



The valley sides cleaned decently despite my challenges I think. It's not like you are going to see them once the intake is put back on, let alone to top cover. Btw, I'm running Evan's in case you were wondering about the brown color.



After I drained the valley.



And I got the one stripped bolt out of the crank.



I did make an attempt at removing the "Jesus" bolt using my 3/4" impact wrench, but the crank started turning and I don't have my locking pin yet (part of the timing tool kit), so I didn't go any further. Based on the "feel" from using the impact, I suspect I'll end up using a 3/4 ratchet wrench and 10 lbs sledge to break it free. Fringe benefit of also working on my tractors is having 3/4" tools at my disposal when needed.

[MrFixIt]

Originally Posted by stunt

I did make an attempt at removing the "Jesus" bolt using my 3/4" impact wrench, but the crank started turning and I don't have my locking pin yet (part of the timing tool kit), so I didn't go any further. Based on the "feel" from using the impact, I suspect I'll end up using a 3/4 ratchet wrench and 10 lbs sledge to break it free. Fringe benefit of also working on my tractors is having 3/4" tools at my disposal when needed.

I highly recommend you use a crankshaft holding tool instead of just the timing wheel locking pin when removing/installing the "Jesus" bolt. It's high torque 310 +fp.

I had to use a 3/4" socket, breaker bar and a 4-foot steel pipe to break it loose like this guy on the video:
BMW 545i, N62, Crankshaft pulley bolt removal "Jesus bolt" - YouTube

Nice work on the valley pan.