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Old 04-14-2019, 06:25 PM
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X5only X5only is offline
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This repair is still fresh in my mind. A few tips:

o Remove the hood, otherwise you simply will not have sufficient working space to access the rear cylinders close to the firewall.

https://www.newtis.info/tisv2/a/en/e...nt-lid/CHs8E9b

o An endoscope camera will save you hours upon hours of aggravation and can make the difference between success and failure.

o The BMW N62 N73 Valvetronic Spring Tension Tool will also save you hours of frustrations if the spring comes off the intermediate levers.

The second picture shows what the "operation theatre" would look like. You won't need anything thing to lay on as you simply don't want to as it comes in the way and therefore would be impracticable.

And here're the notes I gathered for myself while tackling this procedure, by no means a DIY instructions by a pro, just tidbits I gathered while researching the project before tackling it. Use at your own risk, I'm not an authority on these matters, I'm not even a mechanic, just a DIY'er.

When using the bungee cord trick:

1. It helps to first Read up on the workings of an internal combustion engine. This helps in understanding why the valves need to be brought to cylinder compression stroke Top-Dead-Centre (TDC) – both intake and exhaust valves are closed at this point - by rotating the engine clockwise and why we need a bungee cord or some other way (compressed air) to keep valves staying closed and from dropping down into the combustion chamber when they’re disconnected from the spring.
https://en.wikipedia.org/wiki/Four-stroke_engine

2. The bungee cord trick: You feed the cord into a cylinder (through a spark plug hole,) turn the crankshaft by hand to raise the piston up, compressing the rope against the top of the cylinder. This keeps the valve(s) held up so you can remove the keepers for seal replacement without having to remove the head to do minor valve repairs. A contributor says given the choice between using the leak down tester vs. cord, the cord would be taken. He would use the vacuum hose since worked perfectly- a vacuum hose is much easier to push down the spark plug hole than a bungee cord. Applying a thin coating of oil on it prevents the rubber from sticking to itself. Don't let the hose touch the ground you'll be feeding dirt in the motor, keep the hose in a plastic grocery bag and just fed it in each time from that. Using a hose/bungee cord will keep the valves closed so you can take the springs out. The combustion chamber will be filled with cord/hose. In this way cord/hose offers reassurance that the valve won’t drop – the valves are fully supported with no chance to drop down!

3.The bungee cord trick:- Turn the engine clockwise until the cylinder you're going to work on is just past B.D.C - botton dead centre- and it's on its way back up - use the red flag to indicate how far up or down the piston is. If the piston's close to TDC you will use much less rope than if the pistons down in the bore. Put the piston to TDC so that you don’t need much rope to keep the valve from going anywhere. So first use the red flag to feel for the piston. Then with the piston close, just feed in the cord then turn the engine gently so the piston goes up the rest of the way. Leave plenty hanging out of the plug hole. You shouldn't have to stuff much in there either unless you are trying to fill the cylinder up with rope with it on bottom dead center. Feed in the rope through the spark plug hole. Leave enough dangling out so you can pull it out again afterwards and in case it drops further in while turning the engine. Continue turning the crank slowly until you can feel resistance as the piston squashes the rope near the top of the cylinder. After you're done with seal replacement, turn the engine backwards (anti-clockwise) a little, keeping an eye on the rope end - you don't want it disappearing down the spark plug hole. Again, just remember to roll the engine a little the opposite way to release the cord when you're done. Now pull the cord out of the cylinder you're working on. Repeat until you're done with each cylinder.

4. ALWAYS check timing! Perform timing verification before buttoning up.

5. Turn engine 4 times before buttoning up. Important- rotating the engine must be done after removing spark plugs from both banks, i.e. left and right side of the engine.

6. A contributor was able to do all 32 valves without using the keeper tool. He used a long, thin, flat head screwdriver (12" long or longer) and using a blob of grease on the tip of the blade of the screwdriver to hold the keepers in the right orientation. Make sure you also put a blob of grease around the valve stem too. Make sure you wipe off the engine oil so the grease isn't runny and mixed with the oil so as you carefully bring in the screwdriver with the keeper on it, the grease on the valve stem will suck in the keeper. Note the way you bring in the first keeper, do it the same way for the second. So when the first keeper is on, push it around the other side so you get ready for installing the second keeper. Dab the keeper tool and wiped off the access. So am the grease was only on the inside of the keeper tool. Then put the keepers in and it goes straight on the valve stem. Doesn't take a lot of pressure or effort. Once it clicks in wiggle it a little to make sure both sides are attached. The grease is what's holding in the keepers to the valve stem.

7. Use camera and mirrors for the rear seals near the firewall.

8. Put the black tab on the cam locks that fit flush. I think they were closer together. Meaning towards the front and back. Yours looks like they were mounted all the way at the ends of the engine. I think the digram on the AGATools shows them mounted to the engine spread wide. But mine was closer. Can't remember which ones but maybe 2 and 5 cam locks? I saw that too when I was mounting them but put them where they sit flush.

9. Put vice grip to prevent rod from sliding out. Harborfreight sells mini-vice grips which are excellent for this task.

10. Turn the motor enough to get the rocker off then back to TDC. When done with the valve stem seal, turn the engine back to where it was when you took off the rocker arm.

11. Very important to label the rockers and make sure you put them back exactly where they had been before. Or do one at a time so you will only have one rocker out at a time...the one for the valve you're working at the moment.

12. Use one pair of those pliers to grab the stem seal then another pair of pliers to clamp the handles together to get a super tight grip then leveraged back and forth until they came off.

13. Place white shop towels in the engine bay to catch items that may drop through, and so that the caught items would be easily visible for pickup with a magnet and such.

14. Adjust crank off of TDC and back to get valves seated. Try to rotate the engine a few times. Important- rotating the engine must be done after removing spark plugs from both banks, i.e. left and right side of the engine.

15. When installing the valve cover back, push the bottom part of the valve cover on first. There’s a red clip that will sit properly. And you’ll feel it click. Be careful you don’t break the sensor as you install it.

16. Tony’s video strongly emphasizes inspection of each and every spring before you put the valve cover back on. It must properly sit in the Vee groove. Also verify that the keepers are seated in the correct orientation per Tony’s video. https://www.youtube.com/watch?v=-1D29BW-xbQ&t=296s. The rocker arm must sit flash on the spring. There must not be a gap between the two as demonstrated in the video.

17. As Tony points out in his video, place shop towels in the cylinder head to catch accidental falling of screws into engine internals that would be unrecoverable otherwise.

18. As you get further and further back into the cylinders, it becomes very difficult to not only install the sleeve but also difficult to remove. Perhaps the AGA metal sleeve is way easier. You may want to just grease up the inside of the rubber valve stem seal And put grease in the valve stem grooves. And just slider her right on.

19. I dabbed the keeper tool with grease and wiped off the excess. The grease was only on the inside of the keeper tool. Then put the keepers in and go straight at the valve stem. Doesn't take a lot of pressure or effort. Once it clicks in, wiggle it a little to make sure both sides are attached. The grease is what's holding the keepers to the valve stem.

21) Turn engine clockwise
-bring engine to TDC on the cylinder being worked on.
-With the CAM lobes on the backside of the roller and the TDC flag in the spark plug hole, turn the engine to where you see the flag crest over.

21) When changing the seals, follow the engine firing order on the bank you're working on, e.g. bank1 cylinder 1-4-3-2. Each cylinder has 4 valve stems.
22) On cylinder number 2, there's a little block on the side of the CAM shaft interferes with the fitment of the foot/fork extension of the tool on the intake valve at TDC. So turn the engine just a little bit past TDC to have enough clearance to do that valve.
23) So first after turning the engine to TDC, we compress the spring on the valve just far enough so that we can remove the rocker arm that seats on the spring. Note that the spring and valve are still one unit and not separated and thus move together. With the spring still compressed, remove the rocker arm. Then turn the engine again to bring the pistion down to create enough space to insert some nylon rope into the spark plug hole and bring the piston back towards TDC. The wad of rope in the combustion chamber will support the valve. Note that the valve and spring are still one piece. - After inserting rope, turn the engine again towards TDC and you should see the valve come up protruding above the compressed spring. Press down on the valve to make sure it does not move at all confirming that the rope is doing it's job. After this confirmation, you can remove the keepers off the valve stem and release tension off the spring (decompress it). The spring can now be removed and the now exposed seal can also now be removed.
10nm is the torque for Cam cap nuts. Insert nuts and tighten by hand without play. Tighten down nuts from inside to outside. Torque 10nm. But the oil line bolt 22nm.
24) The keeper tool does get a bit tricky, but once you know how to put the keepers in, it's a walk in the park after that.

25) What we like to do is finish the intake valve seals and install the rocker arms all at the end.
- Use the chalkboard to mark the timing chain where it last stopped before removing the rocker arm out of its place.
- Put zip ties around the roller to hold in place. I did have the last one closest to the firewall pop off and boy was it a bitch.
- The only way I do it is with the piston at TDC of the compression stroke
make sure to fully seat the seal. The spring will not fully sit it. Use a short 16mm socket to press the seal in.
26) You might want to look at your Valve guided too. Are you cleaning the sits before installing the valve stem seals? Mine had a little carbon built up so as I changed them I was making sure I clean before installation.
If you happen to reinstall the rockers, hand crank the engine about 4 times.
27) Also make sure to rotate the engine a few times and check again that the springs are good and Seated right. Just make sure to check no seal top oval springs came off and make sure all the springs are sitting correctly.
28) To prevent the valvetronic spring from slipping off the intermediate lever V-groove (it's a nightmare to put it back into the groove), do not turn the engine clock-wise when creating space to insert cord or when removing pressure from the cord after you're done. Turn the engine backwards only as needed. When done with a cylinder, turn the engine clock-wise a couple of times.
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Last edited by X5only; 04-14-2019 at 10:52 PM.
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