Bmw n52 valve cover tightening sequence
Now that the weather is warmer here in Connecticut, I'm beginning to attack some of the issues I've noticed with my BMW i. This week I'm addressing an extremely common issue found in BMW's magnesium valve cover N52 engines - Oil leaking at the valve cover gasket as a result of broken valve cover bolts.
In an effort to save weight, BMW used magnesium extensively in the N52 and to prevent the galvanic corrosion common with steel fasteners, as well as deal with issues related to thermal cycling.
Due to this, aluminum alloy bolts are required in various parts of the engine. The process is relatively straightforward with the most time consuming steps being valve cover and fuel injector harness removal. Working carefully, the cover can be removed in about one hour. As a result of the bolts snapping, oil will leak directly into the bolt holes and prevent the bolts from seizing in the hole.
This makes what would normally be a painful job surprisingly simple. I've provided a picture to illustrate how you can use two pick tools to rotate the broken stud out of the cylinder head and what the broken bolt looks like once it's been unscrewed.
I like to start by disconnecting the battery ground. The battery is located in the trunk and accessed easily by removing a single panel. Disconnecting the battery will not affect paired phones, seat memory, radio presets, service data etc. After removing the cover, you must remove the ignition coils which is a fantastic opportunity to check the condition of your spark plugs.
Earlier in the year with 70k miles on my plugs I had extreme electrode wear on my cylinder 1 plug which warranted replacement. Now is also a good time to remove the upper hose from the expansion tank. The rear breather hose connector can get brittle on older vehicles, I normally press the tabs in, firmly push the hose forward and then remove it. After removing all of this equipment, remove the white ECM box cover and lift the harnesses out of the cover and away from the valve cover.
The goal here is to get as much working room as possible to remove the valve cover. You can now remove the 19 bolts that retain the valve cover to the cylinder head. Removing the valve cover takes extreme patience as maneuvering around the Valvetronic assembly in such a tight space is a nightmare, but it can be done.
Carefully clean all the gasket mating surfaces and clean off any dust or debris that may have ended up in the head. Debris can plug oil galleries or end up in parts of the engine that may cause catastrophic failure, so take the time to inspect everything. The new valve cover gasket is extremely easy to install as two dowel pins locate it in the head.
Take notice of how the two other gaskets press into the valve cover, so you don't install the valve cover and have to remove it again because the eccentric sensor harness won't plug in. Lastly, when torquing the bolts, follow the factory recommend torque value and procedure to the letter. These aluminum screws will snap easily and without warning if the procedures are not followed.
Once the car is back on the road, allow three or four driving cycles for the engine to adapt to the changes. The car felt fantastic the first time out, but I observed an idle speed that was higher than normal. The next morning it sorted itself out and the idle has been dead solid since.
Prior to replacing the gaskets, it would idle hunt noticeably. Part three covers the reassembly process. In part two, we show you how to install the new components.Repair Summary This article gives detailed instructions on replacing the valve cover gasket in a BMW E60 5 series vehicle with the N52 engine.
Even though we used a xi touring wagon to perform this repair, this article can be applied to any BMW vehicle with the N52 6 cylinder engine with minor modifications to the repair steps. This article is for replacing the valve cover gasket on the N52 6 cylinder engine only. The N52 engine was found in many different BMW models from approximately If you are not sure which engine your BMW has, please use the following engine identification tool before beginning this repair:.
Get my BMW engine model number. In BMW introduced one of the most popular engines ever produced by the company…the N52 naturally aspirated six cylinder engine.
BMW E60 Valve Cover Gasket Repair – 2004-2010 5 Series – N52 Engine
It was to take the place of the aging M54 six cylinder engine, the reliable work horse that had powered a huge range of vehicles through the early part of the s. The N52 engine was assembled with two different valve covers, depending on the year and the model of the E60 5 series. As a general rule of thumb, all U. The E60 i was assembled with a plastic valve cover with steel bolts and a rubber gaskets. Both valve covers have their unique issues and are prone to premature oil leakage.
If you are repairing a non U. E60, please verify which type of valve cover you have prior to ordering below. The main cause for magnesium valve cover leaks are due to broken aluminum mounting bolts that allow oil to seep between the metal gasket and onto the engine block. The magnesium covers are also notorious for breaking the three bolts sealing the spark plug tubes allowing hot engine oil to flow into the coils, causing rough idling and cylinder misfires.
This is the reason the aluminum mounting bolts must always be replaced when conducting a BMW E60 valve cover repair. The plastic valve covers were produced with steel mounting bolts which do not break and can be reused when performing a BMW E60 valve cover repair. The plastic covers were assembled with rubber gaskets that tend to crack with heat and age, once again allowing engine oil to bleed onto the hot engine surface and into the coils.
The plastic covers can also crack and should be checked thoroughly when replacing the gaskets. Another source of oil leakage in both magnesium and plastic covers is the rubber gasket sealing the eccentric valve sensor. The eccentric valve sensor is located on the front of the cover, and is sealed with a small rubber gasket that is prone to becoming brittle and oozing engine oil. Even though this inexpensive gasket can be replaced without doing this repair, it is much easier with the valve cover off of the vehicle.
The required parts for a BMW E60 valve cover repair are the valve covers gaskets and the eccentric valve sensor gasket. If you are replacing the gaskets on a vehicle with a magnesium valve cover, then it is also mandatory to replace the aluminum mounting bolts.
The steel bolts on a plastic valve cover can be reused and do not need to be replaced. If you are not sure what type of valve cover you have or are driving a non United States delivered vehicleit is always a good idea to check before ordering.
Use our engine identification tool at the beginning of this article if you are not sure. Valve cover gaskets required — Choose your gaskets from one of the following options. Option 1 — Magnesium metal valve cover gaskets — Gaskets are made of metal.
Always replace the aluminum mounting screws. Option 2 — Plastic valve cover gaskets — Gaskets are made of rubber. All BMW E60 i cars. Eccentric valve sensor gasket required — Always replace this rubber gasket on both magnesium and plastic valve covers.Remember Me?
Hello all, I decided to save some money and am planning on replacing my valve cover gasket got a broken bolt this weekend on my '06 z4 3. I've done a good amount of research on this already but still have a couple questions regarding the installation of the aluminum bolts: 1. I was told however by my local private german auto shop that there is a sequence to be followed on installing the bolts on the gaskets.
Bmw N52 Valve Cover Tightening Sequence
Does anyone know of this sequence? I also have read that the bolts are torqued to 7 Nm. But then there's this method of doing a 90 degree tightening? Can someone provide some further explanation on what this is exactly? Thanks in advance! Appreciate 0. Here's a decent DIY on this task. The bolts are torque to yield and are one time use only.
The torque values are the initial torque value, then after you've set them to that torque, let them rest for 30 minutes or so, then verify the torque, and finally turn them an additional 90 degrees. Originally Posted by basuni One additional 90 degrees. The initial torque puts the bolts in tension and stresses the molecular lattice of the aluminum.
It will settle a bit after a rest period, which is why you verify the torque after the rest. The 90 degree final turn takes the bolts into the yield strength stress on the aluminum which gives a consistent tension on each of the bolts.BMW N52 valve cover and spark plug replacement e91 328i
Going further takes the aluminum into ultimate tensile strength forces which is where you have snapped them in two. Because you take the bolts into the yield strength region you can only use them one time. I did a VCG replacement 9 months ago and before I read this.
Then I only did the initial torque down. Next time I'll do it right. I had a leak free car for 8 months or about 10, miles.
The new leak is at the center point of the exhaust side. I'm currently losing about a quart every fill-ups, so this probably isn't super urgent. My z4 3. I did the spark plugs and all valve cover gaskets atand everything else looked good then. And except for the obvious leak everything still does look good on the outside.
All else being equal, I didn't follow the proper torquing procedure as outlined in this thread. Does anyone think I need to consider anything else when redoing the VCG, such as replacing the valve cover itself? Last edited by Forbes; at AM. Reason: grammar. Find More Posts by Forbes. So I resealed my valve cover a couple days ago. I had replaced the gasket about 9 months ago because it was leaking then. I followed this Youtube video to the letter. The guy's camera angles and dialogue are very good.This article can also be used as a guide for replacing the eccentric shaft sensor.
The work was done on a xi so procedure may vary slightly on other models but probably not by much. To do this job properly you will need a valve cover gasket seteccentric shaft sensor sealcamshaft adjuster seal and spark plug tubes. Some other parts you may want to consider purchasing are a cabin air filter and spark plugs. Once the cabin air filter box is out of the way, remove the cowling by unscrewing the two screws.
There are some wires and sensors that are attached to the cowling so unclip them and lay them aside. Once the wiper arms are off you will need to remove the wiper motor cover, the cover that is right up against the windshield. Start by pulling off the windshield washer hose. The wiper motor cover clips on to the seal that goes under the windshield so you will need to carefully pry it up. Once it is loose unclip the wiring connectors for the heated washer nozzles if your car is equipped with those.
Remove the wiper motor cover and lay it aside. Remove the 3 screws for the center of the trim that mounts to the firewall and remove the center section. Remove the two screws that hold the passenger side trim to the firewall, unclip the wiring and remove the trim. Once the cover is off start disconnecting the electrical connectors. Fuel injector harness unplugs by pulling up on it. It will take some force so try to pull up on it as evenly as possible to avoid damage. Move the entire wiring harness over to the passenger side of the car.
You can use some zip ties to keep the wiring in place and out of the way. Unclip the coolant expansion tank breather hose. You will have some coolant drip out of the hose so have a rag ready to catch the spilling coolant. Unclip the breather hose at the back of the valve cover. You can always return it back to us if you end up not using it. Pull out the ignition coils. You'll have to wiggle them a bit side to side first to get them going. Be careful not to break the connector clip.
Remove the camshaft adjuster motor by removing the three screws. It will just push out once the screws are loose.Remember Me? Anyone know the valve cover bolt torque specs?? Engine is an N Appreciate 0. Lieutenant General. There are numerous DIY's for this that have the spec. Try Pelican Parts. Eric the car guy has a great DIY on ytube for this with lots of practical tips.
And there is a DIY sub forum here. Last edited by ctuna; at PM. Originally Posted by Eddien Or somebody already did the job and the bolts weren't painted.
I have never heard of steel bolts on an N Most of the head gasket kits from the better known places come with the Al Bolts. The steel bolts would be significantly heavier, as well as magnetic.
Aluminum is not magnetic. Lieutenant Colonel. This is because they have plastic black valve covers, and the bolts go into the head, which is aluminum, not magnesium.
Steel into aluminum is ok as far as I know. The engine block is magnesium alloy, so anything goes into block is required to be aluminum.
But valve cover bolts go into head only. Because the valve cover is magnesium they require aluminum bolts, and not reusable, even if the head is aluminum.
And some people hand torque these although I think that is kind of risky. Thanks for your input everyone. I know I posted the specs and I sounded dumb but I was just confirming. Also for everyone's knowledge. My bolts did not have blue on them and I've owned the car since new so no ones touched them. Thanks again for you're help! All N52's have magnesium engine block, and also all N52's have aluminum engine cylinder head.
First year N52's have magnesium valve cover, later year N52's have plastic valve cover. Because valve cover bolts only go into the cylinder head and not reach the engine block, the difference in valve cover bolt material between them is only due to the difference of the valve cover material, not the rest of the engine.
In other words first year N52's require aluminum valve cover bolts only because they have magnesium valve covers.This DIY is going to be centered around handling the replacement of a valve cover gasket and associated gaskets on N51 and N52N engines. Unlike early N52 engines, which used a magnesium valve cover and had an external crankcase vent valve, the updated version features a plastic valve cover with an integrated PCV valve.
One thing to note about the N51 and N52N engines is that the valve cover screws DO NOT need to be replaced, unlike the magnesium valve cover which requires special aluminum screws which are also prone to breakingthe N51 and N52N engine's valve cover has encapsulated hardware.
You can ignore the symptoms of a failing valve cover gasket for a while. However, if you let it go too long, it can result in costly damage. Some of the major symptoms are:. I must stress that this is not a basic or straight forward job; i t will require basic automotive skills and some finesse. Depending on the vehicle you're working on, you may have more or less stuff to move out of the way before you can access the valve cover.
I was able to complete the job in about 5 hours doing it my first time, however it may take you more time or less time based on your experience. This step is going to vary based on what car you own. For an E8X 1-series or E9X 3-series, you will start off by removing the cabin filter housing, AUC sensor if equippedstrut brace if equippedengine acoustic cover, etc.
Basically, this first step is to open the engine bay up and get the other equipment out of the way. At this point, it's a good idea to disconnect the battery ground cable in the trunk to make sure you don't inadvertently short anything out as you will be moving harnesses and disconnecting a lot of electrical components in this job. All you need is a 10mm box wrench or socket on a ratchet. Once the bolt is loose, pull the terminal connector off the lead on the battery and put off to the side:.
At this point, it's time to start disconnecting all of the electrical connections. On the intake side of the engine, you will need to disconnect the fuel injector harness, oil pressure sensor, oxygen sensor connectors, and anything else in the way.
The fuel injector harness is one plastic housing with individual connectors that plug into the injectors. Using a small pick tool, pull the small metal clips up and back. Make sure you do not lose the clips as finding replacements in next to impossible.
Once all the clips are pulled back, pull the injector harness up and out of the way. When doing this, make sure that there is not too much tension on other parts of the harness.
If there is, trace the wires to the source of the tension and disconnect if possible. You will also need to remove the e-box cover on the passenger side of the engine bay. The locks on this cover slide into the unlock position, allowing you to lift the cover out of the way.It is the last of a tradition from BMW that dates back to If necessary the oddments tray can be lifted with a small installation hook at the center screw hole arrow. BMW X3 E83 muffler valvegolf tee alternativeReading posts about forcing the muffler tailpipe valve to stay open by removing the vacuum hose and plugging itIf you open the rear hatch and remove the drivers side cover where the DVD and Sat radio go you will see a small solenoid valve with 2 vacuum hoses attached--the soft hose goes directly to the vacuum pot on the muffler--you can.
Here is my gripe; BMW knows that this is a design problem versus a maintenance issue but refuses to repair. Dd15 front seal installer Dd15 front seal installer. The first step is to pull the engine's valve cover. Antarctica :: Antarctic Treaty System. Be careful, remove the cover of the membrane slowly. Using an oem gasket I would think that the sequence would be something like upper then lower center, upper right next to center, lower left next to center, lower right next to center, upper left next to center.
The Bosch Battery Nationwide Warranty Bosch batteries are warranted to be of merchantable quality and fit for the purpose for which they are designed and ordinarily used, and free under normal use and. If it's in the budget, but a whole valve cover from FCPEuro. Further details of the machine including fully electronic sequential fuel injection with multi-point intake manifold fuel injection -sited,  mapped direct. Truck tires do wear out eventually. You need to tighten the bolts to 8 Nm or 70 inch pound.
While the N52 uses a magnesium cylinder head cover, the new engines use a plastic cover. N52 head bolt torque N52 head bolt torque. Insert cylinder head bolts 1 to 10 with special tool 11 8 I have had not a good experience with BMWs s: leakages or engine wasn't reliable. Geachte Heer Zijlstra. Tap the cover left-right to center it. These bolts have a known history of breaking. Previously inBMW introduced the beginning of a new generation of six cylinder engines with the N Example 2.