[rich_mane]

So I ran into this issue just over a week ago where my car stalled and died a few miles after doing the oil filter housing gaskets. Engine wouldn't turn over with the starter like it was seized. I feared the worst, as there are a few people that complained of the rod bearings failing directly after this repair. So my mind immediately jumped to that.

Once the car died, I fetched my big ratchet and tried to turn the motor by hand. I found that it wasn't "seized" but still was too hard to turn for the starter to be able to turn it over. It only binds in a certain spot, and turns normally everywhere else.

So I started with removing the oil filter and inspecting it for metal shavings. But as you can see from this picture, there really wasn't anything alarming found. A good sign that the bearings are OK.


I also drained the oil and used a funnel with a screen to catch any large metal particles that may have been present. It caught barely anything. Another good sign as far as the bearings go.


I grabbed a sample of the oil that I will send out to blackstone just to get an idea of how things are looking inside. But without signs of metal in the oil, it's not looking like a bearing failed.

So I pulled the valve cover and started inspecting there. I don't have a timing tool handy, but from looking at the cams it would appear they are in time. Barcodes are both facing upwards and look to be in the same position.


While turning the motor by hand, you can see the exhaust VANOS unit's sensor plate moving independently from the gear. It seemed to get caught and then kind of spring forward once it clears the blockage.
It turned out that the exhaust gear sensor plate was coming into contact with the exhaust cam sensor. This was part of the binding that I was experiencing. After removing the cam sensor, the motor starts to turn easier, but still has a spot where it has a bit of trouble going all the way around. This always seems to happen when cylinder 2's intake valves are fully opened.

With the cam sensor out, when turning the motor by hand, I still see the exhaust VANOS sensor wheel move independently from the rest of the unit. This only happens about once every full turn, and it seems to just hit a spot where it binds, and then springs forward even without the cam sensor in place. So it would seem that my problem lies within the exhaust camshaft/VANOS unit or in the exhaust valves. In the video, you can see that it seems to make a click noise and bind slightly when opening the exhaust valves on cylinder 1.

I guess this is good news compared to a rod bearing issue.

SO basically I have to figure out why the exhaust camshaft is acting up. Gonna do a leakdown test to check for bent valves as soon as I get the bmw spark plug adapter for my kit.

The car does not have a single code stored in the DME.

I had a couple people asking for updates on this, so I figured I'd post a new thread up rather than clutter the existing ones. I'm open to any and all speculation and help and i'll be updating it when I figure more out.

[MartinWake]

omg when I read the tittle, but I am glad it was not a rod fail for you!

[fatty335]

Originally Posted by rich_mane

So I started with removing the oil filter and inspecting it for metal shavings. But as you can see from this picture, there really wasn't anything alarming found. A good sign that the bearings are OK.

I also drained the oil and used a funnel with a screen to catch any large metal particles that may have been present. It caught barely anything. Another good sign as far as the bearings go.

Great news! While you certainly do have an issue somewhere in the top end, you motor seems to be OK. Please keep us updated...

[TheMidnightNarwhal]

Nice! At least your engine doesn't look dead.

Question is would your OFHG job caused this issue because right before that your car was running perfectly fine right?

[bbnks2]

Originally Posted by rich_mane

With the cam sensor out, when turning the motor by hand, I still see the exhaust VANOS sensor wheel move independently from the rest of the unit. This only happens about once every full turn, and it seems to just hit a spot where it binds, and then springs forward even without the cam sensor in place. So it would seem that my problem lies within the exhaust camshaft/VANOS unit or in the exhaust valves. In the video, you can see that it seems to make a click noise and bind slightly when opening the exhaust valves on cylinder 1.

As odd as it may sounds, I think this might be normal.

My exhaust VANOS did the exact same thing on the engine stand after rebuilding the engine. I tore down the cylinder head and and could not find anything wrong. No bend valves. Springs were fine. No issues with the rollers. The exhaust side is fairly simple. I could feel the VNAOS unit kind of "loading up" in tension and then releasing (kickign back) same as you describe.

I think it could be oil pressure related. I found some video on Youtube (in german) describing this kind of noise and VANOS issue on a car with low oil pressure. So, I decided to just button everything up and I have had 0 issues with the car (well not zero but that's a different story). No noise. Good compression. Car makes good power. And again, visual inspection showed 0 issues.

Seems odd the incremental wheel would be contacting the cam sensor. Are you sure it actually was hitting it? That seems almost impossible. The VANOS unit would have to be loose or the cam so severally bent that your cam ledge/bearings would be destroyed. Is there damage on the sensor?

Could you have a failing starter motor? Mine failed at around 110K miles. I was getting random no crank no starts until the start died altogether and left me stranded while out on lunch break. If you can turn an engine over by hand then the starter should be bale to turn it over lol... You can MAYBE rotate and engine at what 20-30rpm? The start motor has enough power to spin the engine assembly at ~400rpms. That take massively more power torque than turning the engine by hand I would think.

[mxchris727]

That's just normal VANOS operation; it will spring forward when the cams are at the right angle (there's roughly 12 degrees of possible movement). That metal in the oil looks really bad; I have NEVER seen anything like that in my oil changes for my own and my client's cars. I hate to say it, but I wouldn't get your hopes up.

[bbnks2]

Originally Posted by mxchris727

That's just normal VANOS operation; it will spring forward when the cams are at the right angle (there's roughly 12 degrees of possible movement). That metal in the oil looks really bad; I have NEVER seen anything like that in my oil changes for my own and my client's cars. I hate to say it, but I wouldn't get your hopes up.

Edit: sorry looked at the pics again and yeah I'd say that is excessive metal.

Not seeing crazy amounts of metal doesn't mean much either. When I spun bearings from oil starvation on the track I didn't have much metal in my filter and the oil also came out fairly clean. There was SOME flakes but not like you'd expect to see from such catastrophic damage. Bearings welded themselves to the crank so fast that not much swarf was generated. But, my engine was locked SOLID and not able to be rotated by hand... I am guessing my bearings were already worn and then that momentary loss of oiling caused enough friction and heat to seize the bearings.

[rich_mane]

And this is why I posted this thread! I really wasn't sure about the vanos unit tensioning up like that. It seemed abnormal enough that I figured the problem had to lie in there. But that video bbnks posted is really similar to what I'm seeing.

I'll have to get a closer look at the cam sensor but I was fairly positive that it was making contact with the wheel. Ill get a picture and see if it has any marring on it.

And yeah, I've never seen anything like this in my oil either but I've also never run it through a filter like this as it comes out. So idk. But the engine turns normally except in a single spot. If it was a bearing issue wouldn't it have trouble all the way around ?

[feuer]

I have seen chunks of metal like that on two n54s that broke oil cooler lines. Both engines survived and still run, one 1 year since, the other 2 years ago maybe. Your engine stalled. So something is going on. Could be piston slap that cause the metal chunks. Could be rod bearings. Could the cam shafts. You need to investigate further.

[rich_mane]

So this is actually an alarming amount of metal in the oil?



Don't know if it's just the picture or what but I hardly see anything in there.

Came in today, inspected the cam sensor. Looks like I was probably wrong about the cam gear hitting it, I don't see any marks. Put it back and turned the motor, I don't think it's contacting.

I initially saw the gear hang up and free as it was passing that sensor, so I guess that's what I thought the hangup was. I wasnt even the only one looking at it, I had someone say they thought the same thing was happening. Guess we were wrong though. Didn't make sense to me either as to how it would happen aside from the cam gear being loose or something but I don't see anything like that.

Started turning the motor by hand again today, barely feel any hangup. It's turning normally again ...???

I think I'm gonna just put it back together and try to fire it and see what happens. I'll feel like a real dummy if it ends up just being the starter lmao.

But I'll still have to figure out why it stalled I guess.

Appreciate all the input though for sure.

[bbnks2]

Originally Posted by rich_mane

So this is actually an alarming amount of metal in the oil?

Don't know if it's just the picture or what but I hardly see anything in there.

Alarming? idk... what does the rest of the filter look like? 3-4 flakes in the entire filter is pretty normal. You seem to have 3-4 flakes in every pleat?

Originally Posted by rich_mane

Came in today, inspected the cam sensor. Looks like I was probably wrong about the cam gear hitting it, I don't see any marks. Put it back and turned the motor, I don't think it's contacting.

I initially saw the gear hang up and free as it was passing that sensor, so I guess that's what I thought the hangup was. I wasnt even the only one looking at it, I had someone say they thought the same thing was happening. Guess we were wrong though. Didn't make sense to me either as to how it would happen aside from the cam gear being loose or something but I don't see anything like that.

That's good. Doesn't change much though lol.

Originally Posted by rich_mane

Started turning the motor by hand again today, barely feel any hangup. It's turning normally again ...???

I think I'm gonna just put it back together and try to fire it and see what happens. I'll feel like a real dummy if it ends up just being the starter lmao.

But I'll still have to figure out why it stalled I guess.

Appreciate all the input though for sure.

Yeah the car stalling doesn't align with a starter issue. Not much help the internet can be at this point. Good luck. Button it up and see what happens. Keep an eye out for metal and knock.

[TheMidnightNarwhal]

Originally Posted by rich_mane

So this is actually an alarming amount of metal in the oil?



Don't know if it's just the picture or what but I hardly see anything in there.

Came in today, inspected the cam sensor. Looks like I was probably wrong about the cam gear hitting it, I don't see any marks. Put it back and turned the motor, I don't think it's contacting.

I initially saw the gear hang up and free as it was passing that sensor, so I guess that's what I thought the hangup was. I wasnt even the only one looking at it, I had someone say they thought the same thing was happening. Guess we were wrong though. Didn't make sense to me either as to how it would happen aside from the cam gear being loose or something but I don't see anything like that.

Started turning the motor by hand again today, barely feel any hangup. It's turning normally again ...???

I think I'm gonna just put it back together and try to fire it and see what happens. I'll feel like a real dummy if it ends up just being the starter lmao.

But I'll still have to figure out why it stalled I guess.

Appreciate all the input though for sure.

Yeah haha don't feel like a dummy if it's just that. Car stalling after OFHG when others had it happened and ended up being rod going rip I would be really worried as well but honestly your issue seems.... I mean, like different ish.

I guess like you say I would give it a go to run or if you really have the time to drop the pan.



Like I'm kind of a noob so don't take my word for it this is just a suggestion but if OP had time and resources dropping the pan and checking the bearings would be wiser? Or just starting the car and if it runs fine he's good to go.

Although these engine after OFHG fails didn't do any particular sound most of the time...

[Pladi]

I honestly dont know but i have NEVER seen any type of metal in my filters or pans where i drain oil. I know its common to have metal particles in oil pans in a very new engine or after breaking period. But after that .. idk.

[Ozzie335i]

OP, I haven't read the entire thread, so pardon me if I am butting in. Was this a car that may have had issues with the VANOS bolt? In many cases the bolts have sheared.

[rich_mane]

Originally Posted by Pladi

I honestly dont know but i have NEVER seen any type of metal in my filters or pans where i drain oil. I know its common to have metal particles in oil pans in a very new engine or after breaking period. But after that .. idk.

Yeah i've never looked closely enough to say the same. The oil goes straight into the drain and filter isn't pulled apart and inspected this closely. So I really don't know.

Originally Posted by Ozzie335i

OP, I haven't read the entire thread, so pardon me if I am butting in. Was this a car that may have had issues with the VANOS bolt? In many cases the bolts have sheared.

I had my VANOS recall done the week I bought the car a few years ago. It's the only repair that was done that I didn't do myself. But from the info and video bbnks posted, it would seem that what I've found is normal operation. Just didn't sound normal to me. I won't be inspecting it any further there as it seems multiple people who had this same noise, and have pulled everything apart and inspected without any issues found.

If anything else, I'll be pulling the pan and inspecting the bearings. But I will probably just try to slap it back together and see if it cranks up. If there's any knock or strange sensations I'll be investigating further.

[Ozzie335i]

Hmmm, so you had maintenance done (recall) on the VANOS just last week and you seemed to focus on there maybe being an issue up there. While I don't know what is involved in swapping those bolts, one rule of thumb in troubleshooting something that is broke is asking if any recent changes or maintenance had been made. From your description of what you saw up top you have a pretty firm grasp in how it operates, and seemed to suspect it, if only briefly. Not pointing a finger at a tech that might have walked away to get lunch and skip a step when he got back, but it seems like something up top is more likely than the rod bearings. Maybe a trip back to the dealer is needed. If the issue is due to a hiccup in the bolt swap you are out a tow charge. Or maybe they should pay for that too. If it is something else you are out 150 bucks + towing for them to tell you what it is, and can then do with that as you chose.

[rich_mane]

Originally Posted by Ozzie335i

Hmmm, so you had maintenance done (recall) on the VANOS just last week and you seemed to focus on there maybe being an issue up there. While I don't know what is involved in swapping those bolts, one rule of thumb in troubleshooting something that is broke is asking if any recent changes or maintenance had been made. From your description of what you saw up top you have a pretty firm grasp in how it operates, and seemed to suspect it, if only briefly. Not pointing a finger at a tech that might have walked away to get lunch and skip a step when he got back, but it seems like something up top is more likely than the rod bearings. Maybe a trip back to the dealer is needed. If the issue is due to a hiccup in the bolt swap you are out a tow charge. Or maybe they should pay for that too. If it is something else you are out 150 bucks + towing for them to tell you what it is, and can then do with that as you chose.

Appreciate the info but as I said, that recall was done years ago. Haven't had anybody work on this car except me since then so if anyone is to blame it's probably myself haha.

[Ozzie335i]

Shit, sorry, I though you had the VANOS done a few weeks ago. My aging eyes.

[cahme]

I don't know if it will help much, but I do have pics of my oil filter where I found metal left in the bottom of my oil drain pan. I didn't have any stalling or starting problems, but like you did pull the valve cover and was unable to find anything of interest (was kinda hoping to find a VANOS bolt head being crushed somewhere). This was over 2 years and about 40k miles ago. I did also get an analysis on that oil which also came up normal.

I did have another episode of metal in the drain pan recently which that and an OPG leak lead me to drop the pan and look at and ultimately replace my rod bearings and my crank looked about perfect.

Anyway, here's a couple of my oil filter pics and the Blackstone analysis from back then.

[rich_mane]

Well, slight update. Put it back together, filled it with oil. Poured a good bit through the filter housing. It drained pretty slowly to the pan.

Unplugged the ignition harness and primed the engine. Cranked it for like 5 seconds, motor seemed to be turning fine with the starter. Did that 3 or 4 times.

Plug in the ignition harness, crank it and it starts to fire a little bit and then locks again. Now the motor is hard to turn by hand again. Oooooof. I kept trying to start it with the starter, it just isn't strong enough to get it going. Smelled some burning after a little while, guessing the starter is burning up trying to turn the motor? Man what a pain in the ass.

So idk what the fuck lol. Gonna have to end up pulling the pan.

[rich_mane]

And probably a final update for a bit.

Turning it by hand again, wasn't bad. Charged up the battery to make sure it had enough juice. Tried starting again.

Motor started turning pretty quick, started to fire again, then made a nasty screech sound and seized completely. Can't turn the crank by hand at all anymore. R.I.P. N55.

Guess it could be rod bearings after all lol. It's full of fresh oil, can't believe it would seize like this without ever starting. Shits crazy to me.

[TheGoodTheBadTheUgly]

Bro I am not the one that is suffering that and it is driving me crazy so I can't imagine how you are feeling now.

You went this far, don't back up. Switch these stupid plastic bearings.