[yeagermeister]

There seems to be plenty of information on replacing the cam bearing ledges and rectangrings on the N54, but very little (if any) on the intake side of the N52 (this all may apply to the N51 and N53, but don't quote me on that.) The intake side is much more involved as you have to remove the Valvetronic springs and intermediate levers. Also, only the exhaust side bearing ledges are replaceable. The intake cam bearing is cast into the head, and head replacement is necessary if things are too far gone.

As with all DIY posts, this is a pretty involved procedure, and this is just my experience, documented. I take no responsibilty for any damage. Get a manual, and follow the specs and order of disassembly and reassembly. I am only posting this because I had a hard time finding info for myself. The manual gives you all of the info you need. Check your work twice, make sure every bolt is torqued properly! Take pictures, notes, label wires if you need to.

Mine: 2007 328xi E91, N52B30AE engine.


I was getting the VANOS codes, primarily 2A82 Intake, occasionally 2A87 Exhaust. I had the starting fluctuations consistent with the VANOS solenoid/cam bearing ledge issue. I cleaned both solenoids, cleaned the connectors. Cleaned the MAF sensor. Replaced the non-return valves (they were fine). It appeared I needed to check the cam bearing ledges. (I've never seen limp mode during the VANOS issue.)

I pulled everything out and found I had what I thought was minor scuffing, but not a deep groove, so I went about replacing the metal hook ring seals with the Teflon rectangrings. If nothing else I feel like the groove can't get any worse now.

This is what the damage looks like:
http://www.e90post.com/forums/showthread.php?t=973045

FWIW:
After replacing the rectangrings, there is no change in my starting issues or codes. Still getting the 2A82 Intake code. But maybe this can help someone diagnose/fix their issues. I'm not sure if the scuffing is just bad enough that the seals aren't working properly or if there's something wrong with the actual VANOS unit. I'd hoped the seals just needed some heat cycles to seat properly, but after a few days of driving there is no change. Hmph to that, and YMMV.

Tools:
Timing/VANOS tools, TDC pin, Timing tension tool (rentable, www.bimmertoolrental.com)
Valvetronic spring tool (114270 or 117110) - good explainer on how it works

E20, 14, 10, and 8 socket (E8 needs to be 1/4" drive, I had to grind mine down to tighten the lower Valvetronic motor bolt.)
Swivel socket adapters and extensions in all sizes
Torque wrenches - I used 1/4" and 1/2" for everything.
Torque driver - 0.5Nm or 4.5 inch-lbs on the timing tensioner. Much lower than a 1/4" torque wrench can go. I ended up buying the Husky 1/4" Hex Torque Driver ($60) and Milwaukee Hex Offset Drive Adapter ($20) from Home Depot.
Angle torque gauge

Parts:
Rectangrings (x4) 11317587757
Cam bolts (x2) 11367524954

Now's also a good time for:
Timing tensioner and sealing washer 11317584723 and 11317534251
Valve cover gasket 11127582245
Valvetronic motor gasket 11127552280
Eccentric shaft sensor gasket 11127559699
Spark plugs

Notes and things to know or expect:

1. If you just want to check for intake side bearing condition, the main (front) bearing cap can be removed and put back in without taking anything off but the valve cover. As long as there is tension on the chain and #1-6 cam bearing caps are in place, the cam can't go anywhere.

2. The Valvetronic spring tool is a must. I got mine on eBay for $235. I just don't see any way around it.

3. You will need to remove the fuel injector rail and injectors to access the intake camshaft bolts.


4. The Spoon pretty much covers everything for exhaust side (on an N54): http://www.e90post.com/forums/showthread.php?t=1080990

(I will add that when you're tightening the cam retainer on the exhaust side, go very slowly (1/4 turns), and evenly. Keep checking to make sure you haven't knocked anything out of line. See example for my mistake (which I did catch. Whew.)):


5. If you have xi/xDrive, it really helps to remove the front driveshaft in order to access the TDC lock pin hole. I did not, and it was a PITA.

The procedure:
1. Car on jackstands. Preferably front and rear, but just front is workable, use wheel chocks. Ramps are a bit too low to get access into the TDC pin location.
2. Remove the front underbody panels. You need access, and you're going to drop something, at least it'll fall out. You hope.
3. Remove front driveshaft if you have one.
4. Disconnect battery.

5. Remove valve cover and all its connected bits.
http://www.e90post.com/forums/showthread.php?t=697252

This video has good info, especially removal (31:00), and installation angle (48:00) for the valve cover:
BMW 6 Cylinder Valve Cover, Spark Plugs, and Eccentric Shaft Sensor DIY

6. Find TDC (Cyl 1 at highest point, QR codes up on camshafts) and lock the engine with the pin. It's pretty hard to find the hole. The plastic blind plug you're looking, er, feeling around for, looks like this:


And it's located way up in here:


7. Mark chain, VANOS adjusters, and impulse sending wheels
8. Remove timing tensioner and seal
9. Remove cam bolts
10. Zip tie chain/gear - set VANOS units into the front cavity so there is some tension on the chain at the bottom. Wouldn't hurt to wire these things up so they don't fall back towards the camshafts while you're working. I move mine up and to the left w/ a bungee cord on the old cam bolt.

Removal
11. Gas cap off, relieve fuel pressure
12. Remove fuel rail/injectors
13. Remove spray nozzle from Cyl 3 guide block
14. Remove Valvetronic springs (keep track of all springs and levers, return to original positions.)

15. Remove guide blocks
16. Remove intermediate levers
17. Remove camshaft bearing cap bolts (these are labeled 1-6, keep orientation correct.)


18. Remove camshaft

Assembly
1. Replace Rectangrings
2. Assembly lube on all cam bearings
3. Install cam keeping QR code up
4. Install bearing caps using assembly lube
5. Torque cam bearing cap bolts to spec
6. Timing tool on
7. Install levers, blocks, and springs
8. Install spray nozzle in line with Eccentric shaft gear
9. Set VANOS adjusters and plates in place, hand tighten cam bolts
10. Set timing tension tool by hand, tighten to 4.5-5 inch-pounds
11. Tighten camshaft bolts to spec + 180 degrees
12. Crank by hand 2x back to TDC, put TDC pin in, and make sure QR codes are back on top of cams
13. Check timing with timing tool
14. If everything lines back up, Install timing tensioner with new sealing washer
15. Crank engine 2x by hand (maybe not necessary, I did this to seat new tensioner)
16. Valve cover on, blind plug in, install injectors and fuel rail, connect battery.
17. Underbody panels on, car off of jackstands
18. Turn ignition on and off 2x before starting to reset Valvetronic motor worm gear
19. Take a deep breath, and start the freakin' car already.

[yeagermeister]

FWIW - this repair did not solve my VANOS code and starting issues immediately. However, after an oil change, and while I was at it cleaning both VANOS solenoids, the problem is now gone.

[cahme]

Reviving an old thread ....

I have a collapsed lifter on my '07 N52 on one intake #5, so I need to pull that cam. My question is around the Valvetronic side ... I'd like to understand why the springs & intermediate levers need to be removed, rather than removing the cam with them in place?

My guess is they're providing tension on the cam which will not be released by loosening the cam bolts (like the valve springs would on the exhaust side)?

[andas]

Probably.. I want to replace my valve stem seals and the valvetronic springs require 250$ tool to remove them... Quite expensive for 1 time use, is there any alternative?

[andas]

Originally Posted by yeagermeister

7. Install levers, blocks, and springs

Did you use the special tool 114450 for guide blocks?

[xiaodong1102]

Originally Posted by yeagermeister

FWIW - this repair did not solve my VANOS code and starting issues immediately. However, after an oil change, and while I was at it cleaning both VANOS solenoids, the problem is now gone.

Did you fix this issue finally? I read your post completely, as I know, it seems that you already did everything for this fault code (2a82). I'd like to know the final result.

[merz.38]

Did you try cleaning/replacing the solenoids at the front of the block first or did I miss that?

I recognize this code and had it flagging periodically until I blew it out w some compressed air. The plungers on the solenoids stick which causes lack of oil flow (which leads to lack of cam phasing)

[AlphaBetaX5]

Having 2A82, i take camshaft sensor on my N52 in my X5.

Did followings:
Replaced solenoids,
Cleaned solenoids
Replaced intake camshaft sensors
Inspected oil level
Filter housing insert inspection




Hesitatation is still there.

I am going to change my 10 months old oil filter today. I saw too much metal shavings on it yesterday!
Hopefully it helps temporarily.

My wife reported heavy hesitation this morning and it is just getting horrible.



Eventually I think I need to do the camshaft ledge seals.

[B230FT]

7. Install levers, blocks, and springs

Replacing a deflated lifter on cylinder #5 (N52).

How did you install the intermediate levers and springs with the cam present?

Excellent write-up!

[Angelcma]

Help, I was doing this and the blind plug broke when trying to remove it. Help

[khhoang86]

just purchased a 07 335i and it jumped timing. what steps to diagnose if the engine self is still good? also how do you adjust the cam thats not properly aligned (barcode up). thanks.

[sanedo_man]

Hey! Could you please share the torque specs for this job? Specifically, for the valve springs, cam ledge? I replaced the rings but can’t really put the whole thing back together without the specs. Need the ones for exhaust side too. Can’t find it anywhere.