[bbnks2]

Originally Posted by ptpending

the whole thing with oil deficit in N55 is that crankshaft shells eat crankshaft or bake to it
so you have to replace crankshaft, and full rebuild will cost more than engine from junkyard

This is true for any engine not N55 specific.

[Pladi]

Originally Posted by bbnks2

I've never heard of any kind of failure associated with the oil control valve. It's basically a vanos solenoid. Pretty simple device actually. If it fails it just means MORE oil pressure will be delivered to bearings rather than bypassing to the pan to reduce pumping losses. Oiling is actually simplified with the N55.

The electronic water pump is actually pretty awesome and has more than adequate flow. Ability to continue cycling water after the engine has shut off (turbo timer) and ability to control cylinder head temps for different driving conditions. Actual oil and water temps have more to do with DME logic than it does the pump itself. I have all stock components and my car sits at 210-220f oil temps... 180-190f coolant temps. What's wrong with the coolant pump? Cost and high failure rate is probably the only reason why they did away with it...

I honestly don't believe that N55's have any more oil related failures than N54. You just don't have N54's being serviced by shops anymore since they are essentially $7k third owners cars at this point... You scrap a car like that when it blows up. N55/N54 in general produce lots of low end torque which = high wear on the bearings.

I also don't believe the Teflon seals BMW switched to with the N55 completely solve the intake cam oiling issues. I think it helps prevent the seal from eating into the cam ledge but now how long does a Teflon seal last before it gets deformed or stretched out and causes the same issue?

To check the intake cam, just remove one of the caps. check the wear. Replace the cap using exact torque specs or you can cause the intake cam to bind up. Then check the next cap... no need to remove the cam altogether. That is a ton of extra work. If you do want to tear it all down, the only thing you really need to keep in mind is that you want the engine locked at TDC and install the cam with the label facing up. This ensure you don't mash valves into pistons. Read up on newtis.info.

I am talking more about the concept of efficiency. The normal oil temps for N55 are up to 250 F . Yours are running a bit cooler somehow but DME is targeting 240-250 on the highway.. and its for efficiency . They have designed the engine with efficiency in mind. Thats all i was saying.

Can you change all that now with MHD ? Yes. But thats not the point. MY point is BMW mentality in design.

The pump is a piece of crap its well known. IT fails on the dot..

Is it capable ? Yes. But it fails too much to give it any credit.

As far as valves yes looks like its a normally open proportional solenoid valve... You are right its a simple device and cant fail anything especially if its designed to be normally open..

I am not discussing N55 vs N54 related failures i said nothing about any of that i was surprised to hear anything about this proportional valve.. it was just news to me

LEts not turn it into that pls we have heard enough. LEts keep this related to this case where OP has taken this engine apart to some degree..

I would like to see the rods maybe if he has time i agree with fatty.

[bbnks2]

Originally Posted by Pladi

I am talking more about the concept of efficiency. The normal oil temps for N55 are up to 250 F . Yours are running a bit cooler somehow but DME is targeting 240-250 on the highway.. and its for efficiency . They have designed the engine with efficiency in mind. Thats all i was saying.

Can you change all that now with MHD ? Yes. But thats not the point. MY point is BMW mentality in design.

The pump is a piece of crap its well known. IT fails on the dot..

Is it capable ? Yes. But it fails too much to give it any credit.

As far as valves yes looks like its a normally open proportional solenoid valve... You are right its a simple device and cant fail anything especially if its designed to be normally open..

I am not discussing N55 vs N54 related failures i said nothing about any of that i was surprised to hear anything about this proportional valve.. it was just news to me

LEts not turn it into that pls we have heard enough. LEts keep this related to this case where OP has taken this engine apart to some degree..

I would like to see the rods maybe if he has time i agree with fatty.

Gotcha I was just clarifying that the DME logic and temperatures actually makes sense and the water pump is more than capable. Also, that the things this guy is mentioning are not some N55 specific issue. No engine builder wants to touch an engine with a spun bearing. It's literally trying to make a pile of junk work again... rods stretch, cranks crack, line bore distorts...

[9krpmrx8]

My first water pump was fine at 75k when I replaced it for GP, would have made it to 100k easily. My best bud has a 2011 with 120k on the original water pump. Lots of mechanical pumps fail in that range. I think the pump suffers more from damage due to not servicing the coolant more often in some environments and from people letting it get soaked in oil due to not fixing oil leaks right away.

[Pladi]

Originally Posted by bbnks2

Gotcha I was just clarifying that the DME logic and temperatures actually makes sense and the water pump is more than capable. Also, that the things this guy is mentioning are not some N55 specific issue. No engine builder wants to touch an engine with a spun bearing. It's literally trying to make a pile of junk work again... rods stretch, cranks crack, line bore distorts...

Trust me, the longer i have mine the more trust i have on it. Alot of anecdotal info on n55 fails. I personally trust mine and not worried it will fail for no reason with good maintenance.

But his comment about the pressure valve was like " thats something i have not heard yet"

But a normally open valve can in no way impede flow when it fails. So i totally agree with you.

Unless its stuck energized somehow. That would be a dme/electrical fail not a valve fail.

My biggest issue with n55 and n54 remains the belt failure design.

That i cannot wrap my head around. I have to buy some kids google sketch up design for a plate that costs 10 times more to protect my engine..

That is the only thing that will always bug me owning this platform

[9krpmrx8]

The belt issue is another that only exists for those who neglect things and don't pay attention.

[ptpending]

Originally Posted by bbnks2

This is true for any engine not N55 specific.

this valve was introduced only on n55 and n20 engines. and bmw have to change it's design and part number after 2012 year
and there are much more problems with crankshaft shells on n55 due that valve

[bbnks2]

Originally Posted by ptpending

this valve was introduced only on n55 and n20 engines. and bmw have to change it's design and part number after 2012 year
and there are much more problems with crankshaft shells on n55 due that valve

tons of part numbers changed in 2012. Can you provide at least a little context as to how that valve supposedly plays a role?

[JonEQuest]

Originally Posted by bbnks2

I've never heard of any kind of failure associated with the oil control valve. It's basically a vanos solenoid. Pretty simple device actually. If it fails it just means MORE oil pressure will be delivered to bearings rather than bypassing to the pan to reduce pumping losses. Oiling is actually simplified with the N55.

The electronic water pump is actually pretty awesome and has more than adequate flow. Ability to continue cycling water after the engine has shut off (turbo timer) and ability to control cylinder head temps for different driving conditions. Actual oil and water temps have more to do with DME logic than it does the pump itself. I have all stock components and my car sits at 210-220f oil temps... 180-190f coolant temps. What's wrong with the coolant pump? Cost and high failure rate is probably the only reason why they did away with it...

I honestly don't believe that N55's have any more oil related failures than N54. You just don't have N54's being serviced by shops anymore since they are essentially $7k third owners cars at this point... You scrap a car like that when it blows up. N55/N54 in general produce lots of low end torque which = high wear on the bearings.

I also don't believe the Teflon seals BMW switched to with the N55 completely solve the intake cam oiling issues. I think it helps prevent the seal from eating into the cam ledge but now how long does a Teflon seal last before it gets deformed or stretched out and causes the same issue?

JonEQuest To check the intake cam, just remove one of the caps. check the wear. Replace the cap using exact torque specs or you can cause the intake cam to bind up. Then check the next cap... no need to remove the cam altogether. That is a ton of extra work. If you do want to tear it all down, the only thing you really need to keep in mind is that you want the engine locked at TDC and install the cam with the label facing up. This ensure you don't mash valves into pistons. Read up on newtis.info.

My reason for saying N55 is more likely to break down than an N54 is that I have rebuilt an N54 recently and it seems I am partially rebuilding this N55 now. The n54 has way less parts in the intake cam side which means way less parts that can break. The N55 has about triple the parts which means higher chance of failure. That is just simple logic on any mechanism. The N54 has one intake cam with one set of bolts holding it and the cam ledge down, and after that it was just rockers and lifters. Now the N55 has electronic valves, worm gears and a few more sets of bolts holding everything together, etc thrown into the mix. I personally know of several N55 owners who have has upper head issues and I don't know of anyone who had cam issues with the N54 except things like a dirty or bad VANOS solenoid. I plan to just pull one cap at a time to avoid any issues but would be surprised if I don't find damage somewhere.

[Pladi]

Originally Posted by JonEQuest

My reason for saying N55 is more likely to break down than an N54 is that I have rebuilt an N54 recently and it seems I am partially rebuilding this N55 now. The n54 has way less parts in the intake cam side which means way less parts that can break. The N55 has about triple the parts which means higher chance of failure. That is just simple logic on any mechanism. The N54 has one intake cam with one set of bolts holding it and the cam ledge down, and after that it was just rockers and lifters. Now the N55 has electronic valves, worm gears and a few more sets of bolts holding everything together, etc thrown into the mix. I personally know of several N55 owners who have has upper head issues and I don't know of anyone who had cam issues with the N54 except things like a dirty or bad VANOS solenoid. I plan to just pull one cap at a time to avoid any issues but would be surprised if I don't find damage somewhere.

You nailed it. And it boils down to what i said earlier to the BMW philosophy with N55 to make it more fuel efficient.

N55 was made for 2 main reasons. Cheaper to manufacture and more fuel efficient in mind.

Valvetronic was put in place for efficiency. Hence more moving parts. This tends to be the theme with N55 especially.

[weehe126]

Originally Posted by JonEQuest

My reason for saying N55 is more likely to break down than an N54 is that I have rebuilt an N54 recently and it seems I am partially rebuilding this N55 now. The n54 has way less parts in the intake cam side which means way less parts that can break. The N55 has about triple the parts which means higher chance of failure. That is just simple logic on any mechanism. The N54 has one intake cam with one set of bolts holding it and the cam ledge down, and after that it was just rockers and lifters. Now the N55 has electronic valves, worm gears and a few more sets of bolts holding everything together, etc thrown into the mix. I personally know of several N55 owners who have has upper head issues and I don't know of anyone who had cam issues with the N54 except things like a dirty or bad VANOS solenoid. I plan to just pull one cap at a time to avoid any issues but would be surprised if I don't find damage somewhere.

So cam guide/ledge issues on N54 is not a normal issue now? This is literally the first cam issue I have heard an N55 having. Having a servomotor go out on a N55 is not a head issue. If you get oil to the eccentric shaft you will never have an issue. I would love to see all of these N55s with head issues.

[ptpending]

Originally Posted by bbnks2

tons of part numbers changed in 2012. Can you provide at least a little context as to how that valve supposedly plays a role?

i wrote that above, problem with crankshaft shells due low oil pressure

[bbnks2]

Originally Posted by ptpending

i wrote that above, problem with crankshaft shells due low oil pressure

OK so you have no idea and you either made it up or copied it from somewhere. Thanks.

That valve doesn't cause any issue with low oil pressure. Find something else to blame. I've never seen anyone show low oil pressure in an N55 either... Except at the track where the pickup runs dry.

[bbnks2]

Originally Posted by weehe126

So cam guide/ledge issues on N54 is not a normal issue now? This is literally the first cam issue I have heard an N55 having. Having a servomotor go out on a N55 is not a head issue. If you get oil to the eccentric shaft you will never have an issue. I would love to see all of these N55s with head issues.

Just people making up more BS. 1 blown N55 gets posted up here over a several month period and the sky is falling... 3 blown n54's get posted up in the various Facebook groups in the past day alone and ally ou hear is excuses. It's honestly just stupid.

[JonEQuest]

Originally Posted by weehe126

So cam guide/ledge issues on N54 is not a normal issue now? This is literally the first cam issue I have heard an N55 having. Having a servomotor go out on a N55 is not a head issue. If you get oil to the eccentric shaft you will never have an issue. I would love to see all of these N55s with head issues.

Besides my 2011 car, I know a guy personally who had his 2012 top end blow up sending pieces of crap into his oil channels, etc. That appears to be what happened with mine too. So far I have found my intake cam phaser spring was grinding into the front surface of it, my intake camshaft is scored up along with the 2 rods that I pulled so far having some crap in the bearings. I am sure the other 4 will have similar results. I am just praying that the crank is not toast. But it seems most N55 failures result in a throw away engine.
Also, for the last several months I have been looking for a cheap car to put my spare 160k mile N54 into. I kept finding several 335i and 535i cars with bad N55 engines. I finally bought this 2011 N55 car because it was a convertible, real clean and it was 1.5 miles from my house. I have yet to find a decent N54 car for my spare motor. Just my personal experience.

[bbnks2]

Originally Posted by JonEQuest

Besides my 2011 car, I know a guy personally who had his 2012 top end blow up sending pieces of crap into his oil channels, etc. That appears to be what happened with mine too. So far I have found my intake cam phaser spring was grinding into the front surface of it, my intake camshaft is scored up along with the 2 rods that I pulled so far having some crap in the bearings. I am sure the other 4 will have similar results. I am just praying that the crank is not toast. But it seems most N55 failures result in a throw away engine.
Also, for the last several months I have been looking for a cheap car to put my spare 160k mile N54 into. I kept finding several 335i and 535i cars with bad N55 engines. I finally bought this 2011 N55 car because it was a convertible, real clean and it was 1.5 miles from my house. I have yet to find a decent N54 car for my spare motor. Just my personal experience.

N54 have vanos adjusters as well... so your specific failure isn't unique to N55s. VANOS units fail. You're also making it seem like N55's are the only cars to ever slip a cam out of timing just because it happened to you. It's not. Your other experience is purely anecdotal as well. Join any of the Facebook groups and you'll see people posting up N54 chassis part outs multiple times a day. You'll have a chassis to drop your N54 engine into within minutes.

Ridiculous people use anecdotal experiences like this to make assertions about an entire engine/car. "Me and this buddy of a buddy of some other buddy both..." stop right there.

Sounds like lack of oiling. It doesn't sound like either the VANOS or the intake cam got any oil. Doesn't sound like the rod bearings got any oil either. I don't think anyone is going to be able to answer why starting a car after it having sat for 3 months would cause an oiling failure. The vanos solenoids and piston oil squirters act as check valves to ensure there is oil in all the galleys when you shut the car off. Maybe they bleed down pressure over time from sitting?

[Pladi]

OP as you can see we have a tendency on this forum to derail very quickly.

To get back on topic. Are you able to provide some rod bearing pictures when you replace them ? IT would be interesting to see the wear for all of us that own this motor.

[JonEQuest]

Originally Posted by Pladi

OP as you can see we have a tendency on this forum to derail very quickly.

To get back on topic. Are you able to provide some rod bearing pictures when you replace them ? IT would be interesting to see the wear for all of us that own this motor.

Here are some photos of my intake cam, cam caps and the head side which is not that bad luckily. I also took a photo of the 2 rod caps (#2 & #5) that I pulled so far last night. They seems to have been contaminated by that aluminum powder than came off the front of one of the cam phasers. Later tonight I will pull the oil pump and the exhaust cam to look at those bearings too. This engine is significantly harder to work on that the N54. Instead of one cam carrier with cam inside held down by a dozen or so bolts I now have to contend with other powerful torsion springs, eccentric shaft, etc. etc. etc. I pulled camshafts a few times on my N54 and it was a breeze compared to this thing. I honestly don't know how I will get it back together. There is supposed to be several special tools you need to use to hold the cam parts in place to put it back together. On my N54 I just laid the cam on top and slowly tightened the bolts a 1/2 turn at a time making many passes until it was down again. Now I guess I need to get more tools to hold it against valve spring and torsion spring tension coming from different angles. I also need to buy about 40 more bolts that last time since every bolt that is not a lug nut on a BMW is a one time use bolt.

[Pladi]

Thanks,

To me looks more like wear from sudden oil loss as suppose to normal wear from over a long period of time with proper lubrication. The caps dont look that good to me to be honest. Maybe the pictures make it seem worse.

As per special tools they are all available from China for 1/10 the price. Those will do the job fine.. All are CNC machined parts.

[bbnks2]

You don't need any special tools. Just a pair of vice grips. Springs are the first thing you take off and the last thing you put on so you're never fighting them. That is literally the only pain in the ass part. Everything else is just drop it in place and torque it down. If you need any help, let me know. I have a head sitting in the garage that I can make you a video of.

The bolts in the head are no different than an N54. The only additional ones you might need to replace are the ones that hold the valvetronic springs down and quite frankly I've re-used them dozens of times without issue while being careful not to snap them.

I would personally hit the intake cam with sandpaper and then polish it up. Or, simply replace it. Cam Caps/head I would sand and polish to smooth the surface back out (dremel with a buffing wheel and compound works great here). This all makes a MESS working in the car so keep things clean. Seal everything off from debris. Pipe clean all holes when your done. Lube all journals. Also, make sure the intake cam isn't binding after it's all torqued down. It might take a few trys to get the caps torqued down right.

Rod bearings are impregnated with foreign metal. Probably from the intake cam. Let's see what the rest of them look like. Replace them and maybe polish the crank quick. Starting to look more like the issue originated at the vanos adjuste or intake cam itself. Somehow not getting oil. Could it be the Teflon seals bleeding pressure after having sat for so long? When you put the new ones on the cam you'll see just how loosely they fit and then rely on the cap to press them into the cam to create a seal.

Like the other poster mentioned about the N52 owners buying N55 intake cams, the N52 engines used the old metal style cam seals and have the same type of cam issues as the N54. It's not valvetronic that causes these issues on the N52 or N55. It's the cam seals. Saying N55 has intake cam issue because it's more complicated and has valvetronic just doesn't make sense. Especially since the "simpler" N54 experiences this failure significantly more.

[JonEQuest]

Originally Posted by Pladi

Thanks,

To me looks more like wear from sudden oil loss as suppose to normal wear from over a long period of time with proper lubrication. The caps dont look that good to me to be honest. Maybe the pictures make it seem worse.

As per special tools they are all available from China for 1/10 the price. Those will do the job fine.. All are CNC machined parts.

I agree that the caps are toast but the head actually looks OK. Maybe the aluminum on the head is a little tougher than the cam or the caps but the head looks salvageable where the cam and caps are pretty badly scored.

[JonEQuest]

Originally Posted by bbnks2

You don't need any special tools. Just a pair of vice grips. Springs are the first thing you take off and the last thing you put on so you're never fighting them. That is literally the only pain in the ass part. Everything else is just drop it in place and torque it down. If you need any help, let me know. I have a head sitting in the garage that I can make you a video of.

The bolts in the head are no different than an N54. The only additional ones you might need to replace are the ones that hold the valvetronic springs down and quite frankly I've re-used them dozens of times without issue while being careful not to snap them.

I would personally hit the intake cam with sandpaper and then polish it up. Or, simply replace it. Cam Caps/head I would sand and polish to smooth the surface back out (dremel with a buffing wheel and compound works great here). This all makes a MESS working in the car so keep things clean. Seal everything off from debris. Pipe clean all holes when your done. Lube all journals. Also, make sure the intake cam isn't binding after it's all torqued down. It might take a few trys to get the caps torqued down right.

Rod bearings are impregnated with foreign metal. Probably from the intake cam. Let's see what the rest of them look like. Replace them and maybe polish the crank quick. Starting to look more like the issue originated at the vanos adjuste or intake cam itself. Somehow not getting oil. Could it be the Teflon seals bleeding pressure after having sat for so long? When you put the new ones on the cam you'll see just how loosely they fit and then rely on the cap to press them into the cam to create a seal.

Like the other poster mentioned about the N52 owners buying N55 intake cams, the N52 engines used the old metal style cam seals and have the same type of cam issues as the N54. It's not valvetronic that causes these issues on the N52. It's the N54 style metal seals. Saying N55 has intake cam issue because it's more complicated and has valvetronic just doesn't make sense. Especially since the "simpler" N54 experiences this failure significantly more.

Thanks for the advice. I will check out the videos when I get home this afternoon. I was thinking of using my metal polish (Eagle 1) and dremel to smooth the parts out but was worried about having too big of a clearance gap for the intake cam. If you have done that successfully before, I may just try that or possibly get a new cam for $100-$150 on ebay. I agree about the rod bearings, they seem to have some of the aluminum flake stuck to them. I have new rod bolts and bearings ready to go. The BIG test is if when I get everything apart and spin just the crank to see if it is binding. If the crank bearings are bad that will be a royal pain. My main issue with the N55 design is so many more parts to pull off. My main issue at the moment is that I need to pull the injectors to get to the exhaust cam tray bolts and I don't have an injector puller yet.