[bbnks2]

Originally Posted by JonEQuest

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.

It's going to be hard to tell if the crank bearings are fine since you'll have the drag of the pistons/rings and pumps to contend with. Chances are they are fine. My main bearings were fine when I spun several big end bearings at the track and literally cooked the bottom end lol.

Injectors should pop out with careful leverage. Sometimes they are kind of corroded into the head and are a PITA. Spray a little wd-40 down the hole. Injector puller isn't a bad investment though.

I have saved worse cams but it was worth the risk for me on a car that is basically just a toy a this point. Replacing the cam is probably your best bet. Clean up the caps the best you can. Slap it together and hope for the best. It's not that much money into it outside of your labor. If it works, it works. If it doesn't then it's not the end of the world. You're out a couple hundred bucks for the parts and time you put into it.

[weehe126]

No special injector tool needed. Just use a 13mm open end wrench and rotate it back and forth as you pull.

[JonEQuest]

Originally Posted by bbnks2

It's going to be hard to tell if the crank bearings are fine since you'll have the drag of the pistons/rings and pumps to contend with. Chances are they are fine. My main bearings were fine when I spun several big end bearings at the track and literally cooked the bottom end lol.

Injectors should pop out with careful leverage. Sometimes they are kind of corroded into the head and are a PITA. Spray a little wd-40 down the hole. Injector puller isn't a bad investment though.

I have saved worse cams but it was worth the risk for me on a car that is basically just a toy a this point. Replacing the cam is probably your best bet. Clean up the caps the best you can. Slap it together and hope for the best. It's not that much money into it outside of your labor. If it works, it works. If it doesn't then it's not the end of the world. You're out a couple hundred bucks for the parts and time you put into it.

I plan to have the cams disconnected, oil pump out and the rod bolts barely put back on to avoid any significant drag. So I should just be pushing the pistons up and down with loose rod caps and everything else will be off the chain. I have a significant amount of resistance now but that could be the rods or the exhaust cam.

[JonEQuest]

I just watched the N52 video and it was extremely well made and I now totally understand how the valvetronic system functions.

[JonEQuest]

I finally got some time to get down to turn the crank and #3 was so loose I could jiggle it around with the rod bolts tight. That bearing spun enough to eat up a lot of metal on the rod and scar up the crank. I am sure some of that nasty metal got to the crank main bearings as well since every bearing in this motor seems to show some damage. The one thing this shares in common with my N54 rebuild last year is that once again it is cylinder #3 that is bad. The N54 had a bent rod and this one spun the bearing on #3. In the future #3 is the go to cylinder I will be looking at for any N54/N55 engine.

Now for what to do....? I am confident I can rebuild this but where I will be to find a N55 crank is a mystery to me. There seem to be none for sale for a decent price. I am so temped to put my N54 into this car but God only knows what coding and rewiring that would involve.

[JonEQuest]

OK, Here is an idea. I know of the redneck method of using sandpaper and a shoelace to evenly smooth out pitted or slightly damaged crank surface. Obviously this one would probably have to be sanded down to the point where the standard size bearing shells are too loose. Has anyone ever had success in sanding down a crank journal until I reach the next size bearing? For example I have a set of STD size bearings and if I sand/grind/polish this damaged one it will be too small but what if I use a micrometer and sand it until I reach the next size of .25 over? For example would I just measure a good part of the crank and sand this one until it is .25 smaller, then use that bearing? I would check with a plastigauge of course but am I understanding the process correctly? I could check it with the micrometer for roundness of course and then be careful how I sand to keep it even. Please only respond if you have knowledge of this process or have actually done this type of work. Saying how it "would never work" based on what was read online is not real advice from personal knowledge.

[Pladi]

Originally Posted by JonEQuest

OK, Here is an idea. I know of the redneck method of using sandpaper and a shoelace to evenly smooth out pitted or slightly damaged crank surface. Obviously this one would probably have to be sanded down to the point where the standard size bearing shells are too loose. Has anyone ever had success in sanding down a crank journal until I reach the next size bearing? For example I have a set of STD size bearings and if I sand/grind/polish this damaged one it will be too small but what if I use a micrometer and sand it until I reach the next size of .25 over? For example would I just measure a good part of the crank and sand this one until it is .25 smaller, then use that bearing? I would check with a plastigauge of course but am I understanding the process correctly? I could check it with the micrometer for roundness of course and then be careful how I sand to keep it even. Please only respond if you have knowledge of this process or have actually done this type of work. Saying how it "would never work" based on what was read online is not real advice from personal knowledge.

A member here : rich_mane has done this.

Not sure if his engine is still working

[weehe126]

I think Bbnks2 might have an extra crank. I do as well. But you can't just slap a new crank in is my understanding.

[rich_mane]

Originally Posted by Pladi

A member here : rich_mane has done this.

Not sure if his engine is still working

1,500 miles, multiple WOT pulls and still running normally with no problems!

Knocking on wood as I type this...

[JonEQuest]

Originally Posted by weehe126

I think Bbnks2 might have an extra crank. I do as well. But you can't just slap a new crank in is my understanding.

If it comes to me needing a crank, PM me with what you would want for it please.

[Pladi]

Originally Posted by rich_mane

1,500 miles, multiple WOT pulls and still running normally with no problems!

Knocking on wood as I type this...

outstanding news.

Are you using 40 weight oil or 30 ?

[rich_mane]

Originally Posted by Pladi

outstanding news.

Are you using 40 weight oil or 30 ?

Still using Castrol GC 0w40. Not sure if I should switch or not.

[Pladi]

Originally Posted by rich_mane

Still using Castrol GC 0w40. Not sure if I should switch or not.

no idea was just curious. 40 weight would probably be better if your clearance is not stock anymore and might be larger a bit.

[bbnks2]

Originally Posted by JonEQuest

OK, Here is an idea. I know of the redneck method of using sandpaper and a shoelace to evenly smooth out pitted or slightly damaged crank surface. Obviously this one would probably have to be sanded down to the point where the standard size bearing shells are too loose. Has anyone ever had success in sanding down a crank journal until I reach the next size bearing? For example I have a set of STD size bearings and if I sand/grind/polish this damaged one it will be too small but what if I use a micrometer and sand it until I reach the next size of .25 over? For example would I just measure a good part of the crank and sand this one until it is .25 smaller, then use that bearing? I would check with a plastigauge of course but am I understanding the process correctly? I could check it with the micrometer for roundness of course and then be careful how I sand to keep it even. Please only respond if you have knowledge of this process or have actually done this type of work. Saying how it "would never work" based on what was read online is not real advice from personal knowledge.

Try hitting the crank with some 800/1000/2000 grit sandpaper, then some rubbing compound, and see how smooth it comes out. Doesn't look like there was too much gouging. Plasti-guage it with a new bearing in place to see what kind of clearance you have. I have not done this with a crank but I've done it with the cams. Crank is a bit more important lol. Worth a shot though. Like I said earlier, worst case you're out a couple hundred bucks and time and effort and you end up swapping in a used engine anyway.

So, car sat for a few months and when you started it up it ate the intake cam and a bearing? Could material from the intake cam have caused an issue on that rod? Dry start? Who knows honestly. I can assure you it has nothing to do with journal #3 though. I have one I am working on that ate #5. Previous one I rebuilt ate #4 and #5. Another one ate #2. Crank usually takes too much damage for the machine shop to comfortably re-finish it but your crank doesn't look as bad in comparison. New N55 crank will run you $1400 or so and will require tearing down most of the engine. At that point you're better off just dropping in a new engine.

Either polish it up and slap it back together or swap in a new used engine. Part this one out to recoup costs or try to rebuild it as a fun project. Sucks but blown engines happen.

[JonEQuest]

Originally Posted by bbnks2

Try hitting the crank with some 800/1000/2000 grit sandpaper, then some rubbing compound, and see how smooth it comes out. Doesn't look like there was too much gouging. Plasti-guage it with a new bearing in place to see what kind of clearance you have. I have not done this with a crank but I've done it with the cams. Crank is a bit more important lol. Worth a shot though. Like I said earlier, worst case you're out a couple hundred bucks and time and effort and you end up swapping in a used engine anyway.

So, car sat for a few months and when you started it up it ate the intake cam and a bearing? Could material from the intake cam have caused an issue on that rod? Dry start? Who knows honestly. I can assure you it has nothing to do with journal #3 though. I have one I am working on that ate #5. Previous one I rebuilt ate #4 and #5. Another one ate #2. Crank usually takes too much damage for the machine shop to comfortably re-finish it but your crank doesn't look as bad in comparison. New N55 crank will run you $1400 or so and will require tearing down most of the engine. At that point you're better off just dropping in a new engine.

Either polish it up and slap it back together or swap in a new used engine. Part this one out to recoup costs or try to rebuild it as a fun project. Sucks but blown engines happen.

Yeah, I have this thing so far apart I may as well go all the way. I truly think that there may be some embedded aluminum on the main crank bearings like I found on the other rod bearings that didn't spin. The engine is harder to turn than it should be. I have nothing to lose to take this one apart and look at the crank mains. I already have to drain everything, drop the transmission, remove the whole engine, etc. after that taking this engine (that is already half apart) out of the car, I may as well separate the block halves and see what I got to work with. I rebuilt the N54 in my other E93 so I have done all of this before, except the crank. It would actually be less hassle and money at this point if I can get this one rebuilt. The only question is how those crank bearings look.

As far as the story from the prior owner that the engine problem started after sitting, if that is true then they must have ran it for a while. Maybe revving it up trying to figure out what was wrong because the #3 bearings were worn down and had to be pried out from flattening out. That combined with the fact that crap got in every bearing.

[weehe126]

I'm guessing the true story is that they stopped driving it after hearing rod knock and let it sit. The timing issue might just be a coincidence, or the cause of the bearing damage/knock from the deposits.

[Kevin39]

That was my thought as well. That it was parked for a reason.

[JonEQuest]

As a former troubleshooting technician I always ask lots of questions involving what happened and when to help me figure out what's wrong with a piece of equipment. But sometimes it's irrelevant because either way it's still broken. I've got enough of this thing apart that I think I have a good theory. There were receipts for recent oil change but I think that dirty oil maybe in the past caused the intake cam phaser to adjust itself so frequently that the spring on the front cap literally wore grooves into the front aluminum housing. Those fine particles of aluminum started getting into all the bearings and caused rod # 3 to get so tight it spun. It also caused damaged to both cams and there bearing races and I'm sure when I get the engine totally apart all find embedded aluminum making the crank bearings tight which is why the engine still offers a lot of resistance to turn over with the cams and oil pump removed. I even have all of the rod bolts loose and the number 3 bearings completely removed of course. Luckily it's not seized. This is just another testament to these engines requiring high quality oil of the proper weight that is changed very often.

[bbnks2]

Originally Posted by JonEQuest

I'm sure when I get the engine totally apart all find embedded aluminum making the crank bearings tight which is why the engine still offers a lot of resistance to turn over with the cams and oil pump removed. I even have all of the rod bolts loose and the number 3 bearings completely removed of course. Luckily it's not seized. This is just another testament to these engines requiring high quality oil of the proper weight that is changed very often.

Do you have the spark plugs out? If not, you will be fighting cylinder compression.

Cause/effect is the hard part with tearing down the engine. Shits busted everywhere but what happened first? Need an actual engineer inspecting tons of engines to draw any conclusions. First hand, I've torn down a handful now and it has been different every time. This one looks like knock/detonation pounded the bearing:

Crank looks like it fared extremely well. Upon closer look, there appear to be heat cracks on the journal surface. The rod itself also took a ton of heat and abuse, but, I am going to try to get it running again with fresh bearings and some sandpaper. Plasti-guage came back between .0015" and .002" as measured from a few different places in the journal which is adequate.

If this "repair" doesn't work I'll tear it down and rebuild it with replacement parts. That was the initial plan. I just wanted to show a video of what this actually looks like for those that think they can slap a new set of bearings in and move on. There is more damage there than just the bearings. Rod is probably outside of BMW's tolerance for roundness and crank journal surface is probably developing cracks. These aren't N55 issues... this is something that happens on any engine that spins a bearing. I made the video more for informational purposes so people can see an example of a spun bearing, what the other bearings look like, and what type of damage to expect.

Part two would consist of sanding the journal and and checking the clearance. Making videos is pretty annoying though so I don't plan on making a diy on how to sand a journal. Use common sense. If you need a diy on how to use sand-paper and polish something then this repair may not be for you.

[JonEQuest]

Originally Posted by bbnks2

Do you have the spark plugs out? If not, you will be fighting cylinder compression.

Cause/effect is the hard part with tearing down the engine. Shits busted everywhere but what happened first? Need an actual engineer inspecting tons of engines to draw any conclusions. First hand, I've torn down a handful now and it has been different every time. This one looks like knock/detonation pounded the bearing:

Crank looks like it fared extremely well. Upon closer looks, there appear to be heat cracks on the journal surface. The rod itself also took a ton of heat and abuse, but, I am going to try to get it running again with fresh bearings and some sandpaper. Plasti-guage came back between .0015" and .002" as measured from a few different places in the journal which is adequate.

If this "repair" doesn't work I'll tear it down and rebuild it with replacement parts. That was the initial plan. I just wanted to show a video of what this actually looks like for those that think they can slap a new set of bearings in and move on. There is more damage there than just the bearings. Rod is probably outside of BMW's tolerance for roundness and crank journal surface is probably developing cracks. These aren't N55 issues... this is something that happens on any engine that spins a bearing. I made the video more for informational purposes so people can see an example of a spun bearing, what the other bearings look like, and what type of damage to expect.

Part two would consist of sanding the journal and and checking the clearance. Making videos is pretty annoying though so I don't plan on making a diy on how to sand a journal. Use common sense. If you need a diy on how to use sand-paper and polish something then this repair may not be for you.

I do have the plugs and injectors out with all valves up high because the cams are out so it should be pretty easy to turn and it is definitely not. That is why I know I need to look at the crank. If the crank is OK/repairable I am going to replace that one piston/rod since the heat would definitely weaken it.

I wish I could just drop the crank down a bit without the whole disassembly. If it is just a little aluminum and polishing will clean it I would love to be able to do that and put new bearings in the from the bottom. Now I have to drain and drop the transmission, coolant, etc.

[JonEQuest]

UPDATE: I have pulled the crank out and the main journals are pretty good. The only issue is that the rod journal for #3 lost about 0.35" of material due to the spun bearing. I found a local place that will regrind the crank for $150.00 and I already have 0.50" over sized bearings on order. I used a micrometer to check everything and all looks pretty good except that one spot on #3, and the #3 rod of course. I will let you guys know how it goes when I get the crank turned.

[bbnks2]

Originally Posted by JonEQuest

UPDATE: I have pulled the crank out and the main journals are pretty good. The only issue is that the rod journal for #3 lost about 0.35" of material due to the spun bearing. I found a local place that will regrind the crank for $150.00 and I already have 0.50" over sized bearings on order. I used a micrometer to check everything and all looks pretty good except that one spot on #3, and the #3 rod of course. I will let you guys know how it goes when I get the crank turned.

Replace the rod if you can. Theyll.need to be balanced though.