Yeah, you can your time to do this job, take a break and enjoy some beers or coffee, attend to your family, come back and continue where you left off. The job is very tasking on your back! Once I'm done, I'll write up a DIY using the bungee cord.

How thick are those bungee cords ?
The shop that did it for me used air applied to cylinders, and they have that AGA tool set. As for the warranty, i have Alpha Warranty Services alphawarranty.com , purchased it with the car 2 years ago, and it did paid off now with those valve stem seal replaced., good that i got it as if not i had to do it myself.
Thanks for those videos.

Just a standard bungee cord, like this one I got from home depot.
https://www.homedepot.com/p/HDX-48-i...8OPB/206802336.

Standard ones fit into the spark plug hole with ample space around it. You just cut off one tip end of the bungee cord and burn it with a lighter so that there're no frills.
Here're the specifications of a standard bungee cord.
Cord length (in.) 48
Cord thickness (mm) 8
Cord width (in.) .315

If the shop used the AGA or BST tool, clearly they didn't remove the cams.:D The purpose of these tools is to change the valve stem seals without disassembling the engine further than the removal of the valve covers. No cams removal and such. Shops therefore make more money as they do more valve stem seals jobs in a much shorter time. For this reason it doesn't make sense not to do the valve stem seals if you're going to remove the valve covers - you've already done 80% of the valve stem seals process. They're right there staring at you and all you need to replace them is the $350 BST tool and a $2 bungee cord:D So if you're chasing vacuum leaks and going to change the valve covers and other seals, why stop there if you know about this process? I didn't know when I did my valve covers twice chasing vacuum leaks, and what a waste of time, money and energy as my X5 still smoked on extended idle of 10+ minutes! And it's not like the valve stem seals last the life of the engine.

No Rope (or Bungy) needed
 

No rope (or bungy cord) needed is needed. I learned this from one of the mechanics at AGA; I mentioned this earlier in this thread (quoted above). It isn't really necessary to use compressed air, insert rope or a bungy cord.


As long as the piston is brought to TDC, the valves will rest quite nicely on top of the piston, only dropping a little bit more. Without compressed air in the combustion chamber, there's no chance the engine will turn over, so no need for the Timing Chain Lock Tool either.

You're indeed correct and I too struggled with this question. It had an air of mystery around it. I'm suspecting intended to instill fear into the hearts of DIY'ers:rofl: However, the key is that if the cylinder is at TDC, you're safe. But even at TDC there's a 6mm hole and the valves are at an angle as opposed to vertical relative to the cylinder. So you can't just fish it out with a magnet. If it slips for some reason, such as accidentally rotating the engine, it's enough where you don't have a way to pull it back up without a nice long fight. Further, the AGA tool requires cylinder #2 to be just past TDC or before TDC. One has to be very careful there not to drop the valve. You see in the pictures I have used towels to cover the sides of the timing gears. I'm pretty sure you took the same precautions. If something falls into the engine depths there (say a stem keeper or a nut etc), you know it will be a disaster. I think using the cord or air pressure is the same thing - to prevent a disaster and make the work easier;).

Valve stem seals done! Engine timing perfect. Buttoning up the engine now after replacing all other seals and gaskets.

What seals did you use?


Sent from my iPhone using Tapatalk Pro

Elring 199440 made in Germany, from Europarts. They're the improved version in design and material over the original factory ones that I replaced.

Darn, I used new OEM. Wondering if they ever revised itm


Sent from my iPhone using Tapatalk Pro

No Rope (or Bungy) needed, continued
 

Actually, there is no danger of a keeper, etc. falling into a cylinder as I faithfully used the black plastic spark plug hole guides provided with the AGA kit and the flag rod to plumb the piston TDC position, as well as faithfully using the AGA cam chain lock tool to prevent any crankshaft movement. With the rope/bungy method there still exists the risk of dropping a valve into a cylinder when backing off the the piston a bit so the valve can extend into the cylinder to put the rocker arm back in place.

You raised the issue of the camshaft balancing lobe on cyl #2. I did the valve stem seals on an 2008 X5 with N62TU engine; #2 had no balancing lobe as described in the AGA Kit (manual manual in error), but did have a balancing weight lobe on #6 (not described in the manual) that I had to work around. I've not seen anyone else describe this anomaly, but did confirm it with AGA tech support. AGA's kit instruction manual is in need of some updates and revisions.