The 1st section of these instructions covers complete dissassembly of the M52tu-M54 VANOS system.
The 2nd section covers reassembly and timing of the M52tu-M54 VANOS system using the
German Auto Solutions M54 Personal Cam Timing Tool Kit.
This procedure is required if you are doing any of the following:
- Replacing camshafts
- Replacing primary or secondary timing chains or guides
- Replacing cam sprockets or related components
- Replacing cylinder head
- Just want to reset VANOS cam timing
The following tools are required to complete this procedure:
- German Auto Solutions Professional Cam Timing Tool Kit.
- Quality torque wrench with a working range of 5-75 ft/lbs.
- 10mm socket
- 12mm deep well socket
- 13mm socket
- 19mm socket
- 22mm socket
- 32mm socket (combination wrench or a large adjustable will work but you won’t be able to torque the timing chain tensioner)
- T30 male Torx driver ( Will need to fit the torque wrench you will be using )
- E8 female Torx socket ( Will need to fit the torque wrench you will be using, can substitute 1/4″ 6 point socket )
- 8mm Allen driver ( Will need to fit the torque wrench you will be using )
- 24mm open end wrench or large adjustable wrench
Recommended M54 parts replacement list with part numbers:
Required Part – Recommended Part – Recommended Based on Wear
- VANOS Unit Gasket – OEM Part # 11361433817
- VANOS Piston Oil Plug with O-ring – 2 required – OEM Part # 11361433513
- VANOS Oil Feed Fitting Sealing Washer – 2 required – OEM Part # 32411093596
- Pri Chain Tensioner Sealing Washer – OEM Part # 07119963418
- Secondary Timing Chain – OEM Part # 11311432177
- Secondary Chain Tensioner – OEM Part # 11311738700
- Intermediate Chain Guide – OEM Part # 11311722651
- Exhaust Cam Stud – 3 required – OEM Part # 11361432373
- Torx Head Bolt – 3 required – OEM Part # 11361432752
- LH Thread VANOS Piston Torx Bolt – 2 required – OEM Part # 11361748745
- Pri Chain Tensioner Spring – OEM Part # 11411706809
- Pri Chain Tensioner Piston – OEM Part # 11311703747
- Intake Cam Sprocket – OEM Part # 11361744263
- Exhaust Cam Sprocket – OEM Part # 11361744262
- Main Drive Sprocket – OEM Part # 11361438565
****** IMPORTANT – IMPORTANT – IMPORTANT – IMPORTANT – IMPORTANT ******
Read the four paragraphs below before you begin any disassembly of your vehicle.
I HIGHLY recommend that you completely read through the entire instructions several times before you begin to familiarize yourself with the procedure. Pay close attention to the first two steps, they will need to be performed during the initial disassembly phase of the engine!
If you cannot have a computer nearby during this procedure, print off these PDF instructions. I highly recommend using a laptop computer at the vehicle location if available over using the printed PDF instructions. The ability to enlarge the pictures on a computer display will ensure that all the important detail information in the pictures will be visible.
DO NOT attempt to perform these instructions using a “Smart Phone”! The pictures contain important details that would be very difficult to view properly on the small display of a smart phone.
Make sure that you read each step fully from beginning to end before you perform any part of a step. Some steps contain multiple procedures, and some steps contain information at the end of the step, that is crucial to completing the step properly. The only time anyone ever encounters a problem when using these instructions is when they start a step before they have read the entire step through first.
Start by setting the crankshaft to TDC. There is an alignment mark on the harmonic balancer that needs to align with the boss on the front timing cover as shown in the picture. It’s a good idea to highlight the mark to make it more visible. In the picture at left I used a pick tool and some yellow paint to highlight the mark.
There are two possible positions for the crank at TDC that are 360 degrees apart. The next instruction block will show how to determine if you have the correct position.
After setting the crankshaft to TDC, check the position of the cams. Note the two holes facing up on the rear ends of the camshafts in the picture at left. If you do not see the two holes facing up you will need to rotate the crankshaft one full revolution and align the TDC marks again.
Do not proceed until you verify that the holes on the cams are facing up and the the crankshaft is at TDC.
Locate the TDC lock pin that came in the tool kit. The lock pin is inserted though the engine block on lower rear drivers side on the engine.
There is a plastic plug installed into this hole by BMW to help keep dirt out of the hole. You will need to remove this plug to use the lock pin. The hole will still have some dirt and oxidation build up on the I.D. that will need to be cleaned out before installing the pin. A wire “bottle style” brush that fits into the hole works best. Clean the hole until the lock pin will slide through.
This is a view of the lock pin hole in the flywheel or automatic transmission flex plate. This is what the end of the pin needs to slide into.
Verify the pin is fully engaged into the hole by trying to rotate the crankshaft with the pin installed. If you can still rotate the crank, rock the crankshaft back and forth slowly near TDC while pushing on the pin until it drops into place and locks the crank. This will be a two person job.
Locate the tensioner lock pin that came in the cam tool kit. Press down on the secondary timing chain at the tensioner guide shoe, then insert the lock pin as shown.
You need to press the guide shoe down as far as it will go. The pin only needs to protrude far enough to overlap the shoe. The pin does not need to extend under the chain. It’s a good idea to tie piece of string or wire to the loop in the lock pin to prevent the possibility of dropping it into the engine.
Locate the cam lock blocks from the tool kit. Starting with the intake cam, slide the block marked “IN” over the square end of the intake cam as shown in the picture.
Preview the pictures in steps 22-24 for a better view of the way the blocks need to be installed.
Using a 24mm wrench at the spot shown, if necessary, slightly rock the cam forward and backward while pushing down firmly on the lock block to seat the block flush with the head surface. The block should slid on easily and be obvious when seated properly.
Remove the exhaust sprocket thrust washer.
It’s definitely not critical, but you may want to mark the side that faces outward for proper reassembly.
The part is symmetrical and will work properly with either side facing out. Marking it just keeps previous wear surfaces mated to their original parts.
While holding the intake cam sprocket from sliding off the cam, remove the intake cam helix cup by pulling outward on it.
The intake and exhaust helix cups are identical, but should be reinstalled back on the cam that they were removed from. An easy way to keep them separate is to put all the intake cam parts in one plastic bag, and all the exhaust in another.
Support the exhaust cam sprocket as you remove the exhaust cam helix cup in the same way as you did the intake.
Once the cup is removed the exhaust sprocket will try to fall forward. You want to remove the both sprockets and secondary timing chain together as an assembly, so preview the next step to see how the chain/sprocket assembly will be removed. Remove the cup, then the chain/sprocket assembly.
If you are not going to replace the secondary timing chain tensioner, intermediate timing chain guide, camshafts or remove the cylinder head, you are finished with the dis-assembly. If you are going to replace any of these, continue until you have reached the end of the dissassembly instructions.
Using a 10mm socket, remove the three top and one side bolt securing the secondary timing chain tensioner.
You have completed the disassembly portion of these instructions.
The next sections covers reassembly and timing of the VANOS system.
Depending on the engine service that you have been performing, your VANOS system may not have been completely disassembled.
If your VANOS has not been completely disassembled you will need to skip ahead in the instructions until you find the point which matches the current state of your engine.
Before you begin reassembly, make sure that you have:
- The crackshaft postioned at #1 cylinder TDC.
- You have the TDC lock pin installed.
- You have the camshafts positioned with the hoses facing upward.
- You have the cam lock blocks installed.
- You have the timing chain tensioner removed.
You need to slip the sprocket up under the timing chain and over the exhaust cam flange. Once slipped into place, rotate the sprocket counter clockwise to take up any chain slack.
Compare the timing arrow location to the top surface of the cylinder head. They should line up as shown in the picture to the left.
You will probably have to slide the sprocket off the cam flange several times while rotating it a link at a time until it lines up properly with the head surface.
Install the modified tensioner into the OEM tensioner location.
Slowly finger tighten the tensioner body just until you feel a little tension. All you need to do here is take up the timing chain slack enough to verify that the exhaust sprocket is properly indexed to the chain.
If you need to tighten the tensioner all the way in to remove the slack in the chain, it is another indication that the chain is stretched and needs to be replaced.
Verify that the exhaust cam sprocket is still properly aligned to the cylinder head top surface. If not, fully loosen the tensioner and go back to step #2.
Once you have verified proper alignment, install and torque the 3 hex studs shown to 20Nm-15ft/lb. Medium strength (blue) threadlock is optional but suggested.
Locate the exhaust helix cup.
Intake and exhaust cups are identical, but if you are reinstalling used cups, it’s best to keep the cups matched to the cams they came off from.
Apply motor oil or assembly lube to the helix cup inside and outside splines. Line up the wide teeth on the exhaust cam helix cup with the wide gaps on the camshaft and helix flange. Install the helix cup and push in about half way. You might have to fiddle with it a little bit to get it started.
This is an easy but critical step.
Lay the intake VANOS sprocket, exhaust VANOS sprocket, and secondary timing chain on the alignment sheet as shown on the left. Align the wide notch on the intake sprocket helix as shown on the sheet.
While keeping the intake sprocket aligned to the sheet, keep repositioning the exhaust sprocket until they both line up with the outline. The exhaust sprocket technically does not have a front or rear so just pick a side to face up. As shown on the alignment sheet, the exhaust sprocket is symmetrical and has 3 possible correct orientations. This is hard to get wrong. If you have a one tooth misalignment it will be obvious.
Apply a film of oil or assembly lube to the front and back faces of both sprockets, the helix splines on the intake sprocket, and the helix splines on the intake cam before installation.
Preview steps 18, 19 and 20 before installing the chain and sprocket assembly. This will help you understand how the assembly will be positioned.
Grasp the chain and sprocket assembly as shown. As you lift the assembly off of the alignment sheet, keep the protruding section of the intake cam sprocket facing toward the engine. Slide the assembly onto the cams while keeping the wide notch on the intake sprocket splines facing up.
Locate the intake helix cup and apply some motor oil or assembly lube to the outside and inside helix splines.
Now install the intake helix cup using the same procedure you used for the exhaust side. Push the intake cup in just until the splined section is flush with the sprocket as shown in the picture.
Starting with the intake helix cup, position the cups as shown in the picture. You want a little bit of the intake cup splines to be protruding as shown. After setting the intake cup, pull the exhaust helix cup ouward until it stops.
Tighten the 3 intake sprocket hex nuts until snug, then back the off 1/2 turn.
Tighten the 2 upper exhaust sprocket Torx bolts until snug, then back off just enough to break them loose. Next, snug the bottom Torx bolt, but DO NOT exceed 5 ft/lbs. Be careful that you do not disturb the helix cup position while working with the Torx bolts. You might want to pull out on the cup while tightening the bottom bolt.
Locate the VANOS unit, we will be setting it up to be used as an alignment plate.
From the camshaft side of the VANOS unit, as shown in the picture, push the intake piston in as far as it will go. Since there will probably by oil still trapped in the unit make sure that you have fully pressed the piston in until it has hit it’s hard stopping point.
Make sure that cylinder head and VANOS gasket surfaces are perfectly clean with all traces of the old gasket removed.
Any pieces of old gasket material or dirt caught between the VANOS unit and head could have a minor effect on timing accuracy. Slide the modified VANOS unit onto the cylinder head studs.
Do not try to push it all the way on yet.
In this step we will pretension the primary timing chain. The tension is not overly critical. Once all the slack is taken out of the chain, further tightening does not accomplish anything. If you severely over tighten the tensioner you could damage the timing chain or guide.
The easiest way to set proper tension without over tightening, is to firmly grasp the exhaust sprocket, (the one furthest from the front of the engine, that the primary chain wraps around) and wiggle it back and forth as you tighten the tensioner. Tighten the tensioner slowly until you can no longer wiggle the exhaust sprocket, then tighten one more revolution.
Again, failure to be able to remove all the slack in the chain with the tensioner fully bottomed out against the head indicates a worn timing chain which should be replaced.
You will now slowly tighten the left hex nut, and right hex stud, to draw the VANOS unit up to the head surface. This will push the helix cups into their proper timing position.
Turn them only 1/2 turn (180 degrees) at a time, alternating between the left nut and the right stud. You do not need to tighten the bottom hex nut yet. Watch the gap between the VANOS surface and head surface, you want to close that gap equally on the left and right sides as you draw the VANOS unit up to the head. Make adjustments to your tightening pattern if necessary to keep a uniform gap as you go.
Once the VANOS unit fully contacts the head surface you can tighten the bottom hex nut. Torque the two 6mm hex nuts to 10Nm-7.5ft/lbs and the 8mm stud to 24Nm-18ft/lbs.
Now remove the VANOS unit, then snug up the bottom hex nut and bottom torx bolt.
Do not torque yet.
Now remove the exhaust torx bolts one at a time while leaving the other two tight to prevent any possible change in the set alignment. Clean the one removed bolt, apply blue locktite, than torque to 20Nm-15ft/lbs.
Once you have one bolt torqued, remove the next and repeat the procedeure until all three torx bolts have been torqued.
Locate the exhaust sprocket thrust flange and apply a film of oil or assembly lube to both sides.
It doesn’t have a front or back and is another symmetrical part.
If you’re fussy you can usually tell which side was originally facing out by looking at the polished contact areas. The side with shinny spots on the very outside edge (like in picture) faces outward.
While leaving all the other hardware tight, one at a time, remove each of the 6 hex nuts, clean the threads, apply threadlock, and torque to the spec shown.
Since you are only removing one piece of hardware at a time there is no danger of anything moving out of position. The BMW manual does not specify threadlock on these, but I feel that medium strength (blue) threadlock adds a margin of safety and has no down side.
Torque the 6 hex nuts to 10Nm-7.5ft/lbs.
Your cams are now properly timed.
Apply some RTV gasket sealer to the two areas shown in the picture, install a new VANOS gasket over the studs and dowels, then apply some more RTV at the same locations on the outside face of the gasket.
I highly recommend Permatex “Ultra Grey” for all engine assembly applications where a RTV sealant is required.
Locate the piston oil plugs.
The O-rings on these tend to harden and need to be replaced. BMW does not sell the O-rings for the plugs separately. New plugs with O-rings cost less than $2.00 each. I recommend just replacing the entire plug rather than trying to find O-rings that fit the used plugs.
Apply some oil or assembly lube to the O-rings then push the plugs into the VANOS pistons until they snap into place.