Purchased a 2009 Base MC two months ago, everything had been running fine until two weeks ago then the vehicle had a low speed hesitation show up, last week it became worse with the engine dying while idling when first started. After it warms up it runs fine at 30mph plus, lower and it has hesitation, 5mph it gets really bad. Took it to the dealership and explained issues, in the mean time ordered a new VANOS solenoid. Get a call from the dealership two days later saying the VANOS oil control rings had worn grooves into the bearing cap and cylinder head, causing loss of oil pressure for the VANOS system. Tech explained oil control rings for the 2009 were still metal, had not yet been switched to polymer (lucky me.........) then quoted me $3000 for the head plus labor 😳 ! . I've researched on here and google trying to find more tech info on this particular issue but not much out there. I'm capable of replacing the head myself, $1100 new from local shop. I also still have the new VANOS solenoid I have yet to install. So questions.... should I install the new solenoid now and see if that helps or will it damage the new solenoid if it is in fact a low oil pressure issue? If I do replace the solenoid do I need to mess with timing if I just take the old one out and put the new one in? Tech said it is currently timed perfectly. Does anyone have a good link on cylinder head replacement, tips, etc?

 

First of all, my experience is with an '07 MCS, so I could be way off base with my comments.

The oil control rings are mounted on the cam, not the vanos solenoid, so there's a good chance your replacement solenoid isn't needed. Then, just changing the solenoid won't fix the damaged cam journals --- you'll still have low oil pressure at the Vanos. Here's a link to RealOEM's pic of my '07MCS cam --- http://www.realoem.com/bmw/enUS/show...diagId=11_3926 with item #2 being the seals. You should look yours up to ensure they're similar. Also, you could pull the cam bearing cap covering the seals to inspect for the damage claimed. This inspection won't affect timing.

Replacing the solenoid shouldn't affect timing, but chances are, there's nothing wrong with the current one. It's not likely low oil pressure will damage the new one, but if the old one is OK, your problem isn't fixed and performance is still shot.

Changing the head on an N12 shouldn't be much different from an N14 (which is my experience), but it still takes time, special tools, and a few hundred bucks worth of parts --- gaskets and TTY bolts. Also be advised that cam caps are part of the head and are NOT interchangeable.

 

Thanks for the reply, so if I understand right the bearing caps are machined into the head? That explains why I have to replace the entire head instead of just a bearing cap......... I'm curious if a machine shop could fill and smooth the grooves instead of a whole head replacement? I'm trying to find a parts list and tool list so I can get things ordered and get this knocked out if anyone can point me in the right direction I would greatly appreciate it. Timing kit, tool kit, etc.

 

Again, I'm referring to an '07MCS. Our cams have no bearings like the crank does. Caps are assembled to the head and "line-bored" as a set of five to fit the cams. Note that each cap is numbered --- zero to 4 for one cam, 5 to 9 for the other. Also, they can be bolted in place backwards --- they aren't keyed, so during assembly, you gotta pay attention to not only number sequence but number placement. If I remember correctly, the only cap that can't be screwed up is your damaged cap --- it only bolts on one way.

I asked the same thing about cap repair. Trick is to find a shop with the right equipment. Closest I came was VAC Motorsports --- maybe check their website for more info / call and discuss the specifics? There's probably others. Since my intake cam was also damaged I elected to go with a reworked head (Thumpers) and racing cams.

First thing you need to do a repair of this magnitude is a Bentley shop repair manual. It'll have most of the instructions you need, plus torque sequence and tightening specs. Pricey but worth it. Special tools include the timing chain set. Most are for N12 & N14 and are available from Amazon, e-bay, and most NAM suppliers. N14 requires a special tool for fuel injector seals, not sure how the N12 goes together. Most other special tools can be worked around. Pay attention to the TTY or "one-use" bolts --- head and vanos / sprocket bolts and possibly others --- spec'd in the Bentley manual. Gasket sets are available from your local dealer and NAM suppliers. Your tool set needs to include a set of torx sockets, both male and female, a good variety of metric sockets / wrenches, and allen wrenches.

Talk to the shop about the head --- does it include lifters, rockers, valves, springs, seals, etc? Or do you need to bring them the old head for a "parts exchange"? Spring compressor will be another special tool req'd.

It's not an easy task, 'specially for a novice to Mini's. Best of luck ---

 

Is there an upgraded oil control ing available? I'm just wondering what is going to keep this from happening again after all this work?

 

It took it ten years. Car parts wear. Take notes of symptoms and perhaps in ten years you'll have to do it again or not.

 

Yes, upgraded oil control rings are available --- probably a dealer only item. I panicked when I bought mine, 'cause they're different material and design. Maybe ask for the service instructions for their installation --- awkward but do-able.

For prevention, keep up with your oil and filter changes.

 

resurrecting this thread..... finally got around to ordering a new head and related parts (luckily have two other vehicles so this one has sat for two months) after pulling the valve cover and VANOS bearing cap and finding the above nightmare..... Aside from the head bolts are there any other single use bolts I'll need for the head replacement? Keeping in mind, new head came with cams installed already.

 

Cam sprocket bolts, all three, are also single-use bolts and should be replaced. If the crank sprocket wasn't loosened, leave it alone, timing can be set with it still tight. Can't think of any others, but the Bentley manual flags them.