[rlesko]

Originally Posted by johnung

Realoem isn’t perfect. It’s just how they decided to categorize parts and diagrams years ago. I’ve gotten incorrect information several times from dealers using my VIN. Just the way it goes.

Yea, I'm hopefully going to verify this over the weekend. Was just posting the proper diagram for people who were or are still confused on which bolt is the problematic one, and where to find it.

[Revoltos]

So, if you replace the alu bolt into an alu block with a steel bolt into an alu block, good luck getting it out for any reason in the future. Galvanic corrosion will see to that. It is has to be either fatigue (due to heat cycles) or corrosion that will cause a bolt like that to shear in the first place. Other than the tension placed on the bolt through torqueing it up, it isnt under any further load. Change it by all means, but just put another stretch bolt in there.

Someone mentioned about the EPS motor earth, it isnt the same earth point as what is being discussed here.
The EPS earth is behind the drivers side front wheel arch liner, it earths into the chassis leg. An area that is constantly soaked during wet weather driving. If you are concerning yourself with earths and bolts, I would recommend finding the EPS earth, taking the nut off and cleaning the contact point on the chassis and the faces of the ring terminal with an abrasive such as scotch bright, reassemble and apply some dialectric grease to prevent water ingress. EPS motors are also prone to failure due to the control module burning out.

[Polo08816]

Originally Posted by rlesko

Yea, I'm hopefully going to verify this over the weekend. Was just posting the proper diagram for people who were or are still confused on which bolt is the problematic one, and where to find it.

I wish the FCP Euro blog post had a more zoomed out photo.

Originally Posted by Revoltos

So, if you replace the alu bolt into an alu block with a steel bolt into an alu block, good luck getting it out for any reason in the future. Galvanic corrosion will see to that. It is has to be either fatigue (due to heat cycles) or corrosion that will cause a bolt like that to shear in the first place. Other than the tension placed on the bolt through torqueing it up, it isnt under any further load. Change it by all means, but just put another stretch bolt in there.

Someone mentioned about the EPS motor earth, it isnt the same earth point as what is being discussed here.
The EPS earth is behind the drivers side front wheel arch liner, it earths into the chassis leg. An area that is constantly soaked during wet weather driving. If you are concerning yourself with earths and bolts, I would recommend finding the EPS earth, taking the nut off and cleaning the contact point on the chassis and the faces of the ring terminal with an abrasive such as scotch bright, reassemble and apply some dialectric grease to prevent water ingress. EPS motors are also prone to failure due to the control module burning out.

+1 on just replacing it with an original aluminum bolt.

If this bolt isn't hard to access, then it should be easy to replace for any person that's somewhat handy.

I guess the question is how soon or how frequently does this bolt actually fail/shear off? I'm inclined to think that it usually doesn't fail in the time period of any extended BMW factory warranty? 6-7 years? You will probably only do this once over the course of the life of the car anyways.

[johnung]

Originally Posted by Revoltos

So, if you replace the alu bolt into an alu block with a steel bolt into an alu block, good luck getting it out for any reason in the future. Galvanic corrosion will see to that. It is has to be either fatigue (due to heat cycles) or corrosion that will cause a bolt like that to shear in the first place. Other than the tension placed on the bolt through torqueing it up, it isnt under any further load. Change it by all means, but just put another stretch bolt in there.

Someone mentioned about the EPS motor earth, it isnt the same earth point as what is being discussed here.
The EPS earth is behind the drivers side front wheel arch liner, it earths into the chassis leg. An area that is constantly soaked during wet weather driving. If you are concerning yourself with earths and bolts, I would recommend finding the EPS earth, taking the nut off and cleaning the contact point on the chassis and the faces of the ring terminal with an abrasive such as scotch bright, reassemble and apply some dialectric grease to prevent water ingress. EPS motors are also prone to failure due to the control module burning out.

A thin coat of Neverseize on threads works wonders. Learned that from a German mechanic decades ago. But I don’t hear it mentioned much now.

Yesterday I happened to read Turner Motorsports recommend cleaning rusted hub lips and then applying Neverseize before mounting aluminum wheels, which I already do. See photos.

[NxTH]

Originally Posted by Polo08816

I guess the question is how soon or how frequently does this bolt actually fail/shear off?

I have never seen this discussed in any F30 forum, chat or wall. This is the first time it has been brought up somewhere I visit, and also full of speculation where the bolt is, if it is. Brings up more questions than answers. As soon as someone points directly to where the bolt is with a source and actual part number, we can just keep losing sleep over something that might not even exist on this platform.

Before we know where and what it is, we don't know if it fails at all. Not like there's a continuous flow of "yet another ground bolt failure" posts.

The title is about a water pump ground bolt, yet we've come as far to state the bolt isn't actually on the water pump, and no other actual evidence of its existence has surfaced. Not saying it's not there, but I'm eagerly waiting for an in-depth answer since it was brought up. I was pretty sure the F30 N55 preventative items were fairly known, and this has never come up on any list I've seen.

[joni_titi]

Originally Posted by Revoltos

So, if you replace the alu bolt into an alu block with a steel bolt into an alu block, good luck getting it out for any reason in the future. Galvanic corrosion will see to that. It is has to be either fatigue (due to heat cycles) or corrosion that will cause a bolt like that to shear in the first place. Other than the tension placed on the bolt through torqueing it up, it isnt under any further load. Change it by all means, but just put another stretch bolt in there.

Someone mentioned about the EPS motor earth, it isnt the same earth point as what is being discussed here.
The EPS earth is behind the drivers side front wheel arch liner, it earths into the chassis leg. An area that is constantly soaked during wet weather driving. If you are concerning yourself with earths and bolts, I would recommend finding the EPS earth, taking the nut off and cleaning the contact point on the chassis and the faces of the ring terminal with an abrasive such as scotch bright, reassemble and apply some dialectric grease to prevent water ingress. EPS motors are also prone to failure due to the control module burning out.

I dont think galvanic corosion is as much of a problem as you may think. There plenty of steel bolt threaded directly in the n55 block, bolt that hold the altenator, the a/c compressor, some of the bolt that assemble the transmission and the engine block, headbolt, just to name a few.

When I did my engine rebuild none of those bolt where stuck or showed any sign of galvanic corrosion. If it would really be a problem I think a bolt that have been there for 10 year would have show some sign of deterioration.

[Revoltos]

Galvanic corrosion might not be such an issue on engine parts as it it is well earthed. Also if its not an area subject to salt water spray then the situation will be improved. Alloy wheels do it on the hubs though as that area doesn't benefit from either of the two previous mentioned situations. In any case, if a non load bearing earth bolt was required to be steel (which is also subject to corrosion) then BMW in all their wisdom would of spec'd a steel bolt.
This post started out with stories of that bolt being a failure point. The only way it would fail is over tensioning through torque and/ or fatigue. So if you were going to a steel bolt what torque would you use into an aluminium thread? It smacks of FCP or whoever the source is trying to drum up some sales or in other words making a mountain out of a mole hill.

Just replace with another ASA bolt and move on with your lives.

[joni_titi]

Originally Posted by Revoltos

So if you were going to a steel bolt what torque would you use into an aluminium thread?

Like any fastener you should use the correct torque for the said fastener depending on is property class (bolt grade).

https://www.fastenermart.com/files/m...en_torques.pdf

Originally Posted by Revoltos

Just replace with another ASA bolt and move on with your lives.

Or any zinc plated or stainless steel fastener available in any hardware store. No need to buy a fancy aluminium bolt when not really needed.

[Revoltos]

So, all that extra energy required to determine torque plus find correct bolt spec etc, all for what? Cant find any issues on here and another forum for that bolt failing.
What to do something preventative? Go change your oil.
Just use the BMW spec'd bolt and be done with. People looking for problems where there isnt one.

[johnung]

I read through this thread. It has too much FUD that is just confusing & serves no purpose. FUD is a sales industry acronym. When a competitor has nothing positive to say, they instead throw Fear Uncertainty & Doubt that confuses people.

The answer is simple! Just buy either the stock aluminum bolt or the upgraded steel bolt from FCP Euro or from your local BMW dealer. Put the bolt in your glovebox. The next time that work is being done under your hood, preventively replace the bolt on your engine. It can save you from a sudden breakdown. The three attached photos have all of the needed information.

IF YOU GET IT, THEN THERE IS NO NEED TO READ MORE.
——————————————————-

For anyone confused by the FUD in this thread, please read on. The facts on this issue are clear.

1) This is a known N55 engine problem that can suddenly cause the electric water pump to stop working, cause the car to overheat and leave you stranded. Common symptoms include Limp Mode, Warning of overheating and error code scan showing CD9010 LINBUS communication fault code.

All this can easily be prevented for a few dollars by replacing or upgrading a single bolt sitting on the engine.

This can be done when some other maintenance is scheduled. I just bought the bolt from a BMW dealer and kept it in the glovebox for my next service appointment.

2) This problem was documented in detail in the FCP Euro blog entry. I independently verified it with two different BMW shops who said that they had experienced it multiple times. Both recommended proactively replacing the bolt.

3) The part number for the bolt absolutely fits the car, whether or not realoem accurately displays it in their database. That doesn’t matter. My mechanic installed it on my own N55 engine and said that it matched the original bolt.

4) There is no exhaustive study (and doesn’t need to be) as to why the stock aluminum bolt breaks, it just does. Speculation is that years of engine vibration causes the bolt to fatigue. The FCP Euro blog provided two fix options:

a) Replace the original bolt with a new identical BMW aluminum stretch bolt. The downside of doing this is that it just resets the clock. The new bolt has the same potential to fail over time. (Original bolt has a male torx head).

b) Replace the original BMW aluminum stretch bolt with a BMW steel bolt in the same size. A few drops of blue loctite on the threads is a typical recommendation for extra protection against vibration loosening the bolt. The steel bolt material is less prone to the head shearing off than either aluminum stretch bolts or even stainless steel bolts. (This steel bolt has a female torx head.)

5) Torque specs are not brain surgery and they aren’t some mystical thing. The aluminum stretch bolt and the steel bolt have different torque specs which is totally normal. Those torque settings are listed in the FCP Euro article and on the photos that I have attached.

BMW doesn’t determine torque specs. The bolt itself determines how much it needs to be torqued. The key factors are the type and grade of the metal from which the bolt was made (usually stamped on bolt head) and the diameter of the bolt threads. It’s easy to Google bolt torque specs and plug those two factors into a table. Bolt length and bolt head size/shape don’t matter.

6) The location of the N55 Water Pump ground bolt is not a mystery either. It’s located on the engine. It’s easy to find by starting at the electrical wiring connector on the water pump itself. Follow the wires feeding the connector to a wire with a large ring terminal on the end that is bolted to the engine. The stock aluminum bolt is a M8 with a male torx head. See photo which shows the big ring terminal bolted to the engine with the upgraded M8 steel bolt which has a female torx head. (The style of bolt head does not matter.)

Hope this helps someone!.

[NxTH]

335 and Active Hybrid 3 (basically a 335) for example are not listed for that bolt on either of those pages. First page's fitment lists a bunch of 5,6 and 7 series. The second page lists a selection of 3 series, excluding the 335. Easy to now see where the confusion has come from.

Realoem can't find something that doesn't exist, so for the 335 it's a different part number / bolt, or it's not there for the model. Waiting on the correct part number specifically for a 335 and another source that isn't fcp euro. A quick web search gives no result for 335 on this matter, but a couple for other models.

[johnung]

Originally Posted by NxTH

335 and Active Hybrid 3 (basically a 335) for example are not listed for that bolt on either of those pages. First page's fitment lists a bunch of 5,6 and 7 series. The second page lists a selection of 3 series, excluding the 335. Easy to now see where the confusion has come from.

Realoem can't find something that doesn't exist, so for the 335 it's a different part number / bolt, or it's not there for the model. Waiting on the correct part number specifically for a 335 and another source that isn't fcp euro.

I’m a source who owns an F30 335, bought the bolt, bolt matched, had bolt installed.

My experience has been that Realoem and even dealer looking up by VIN is not always accurate. It’s not like realoem is showing different part numbers. It’s just completely blank on the existence of the bolt and on the big ring connector that my car obviously has. I haven’t searched every single area in realoem but I went through all of the ones that made sense Line by line. This is the 4th time that I’ve experienced something similar.

[Polo08816]

Originally Posted by johnung

I’m a source who owns an F30 335, bought the bolt, bolt matched, had bolt installed.

My experience has been that Realoem and even dealer looking up by VIN is not always accurate. It’s not like realoem is showing different part numbers. It’s just completely blank on the existence of the bolt and on the big ring connector that my car obviously has. I haven’t searched every single area in realoem but I went through all of the ones that made sense Line by line. This is the 4th time that I’ve experienced something similar.

I wish FCP Euro provided a more zoomed out photo of where that bolt is because it the picture about 2 posts ago doesn't match up with the 135i that FCP Euro was using in their video:

[johnung]

Originally Posted by Polo08816

I wish FCP Euro provided a more zoomed out photo of where that bolt is because it the picture about 2 posts ago doesn't match up with the 135i that FCP Euro was using in their video:

https://youtu.be/82ukwTlD-oA

I do not understand why that matters. Find the electrical connector on the water pump and simply follow the wires from it. It should be a fairly short wire with that big metal ring connector bracket on the end in the FCP photo that provides the electrical ground when it is bolted up against the engine. Should be easy to spot. The mechanic who swapped the bolt for me said it was no big deal.

[Polo08816]

Originally Posted by johnung

I do not understand why that matters. Find the electrical connector on the water pump and simply follow the wires from it. It should be a fairly short wire with that big metal ring connector bracket on the end in the FCP photo that provides the electrical ground when it is bolted up against the engine. Should be easy to spot. The mechanic who swapped the bolt for me said it was no big deal.

Chances are the people who are in inquiring where this bolt is are planning on swapping it out themselves. They want to visualize what exactly they need to remove to get to (likely the underhood shield, but anything more?) where they expect the bolt to be. That's why I mentioned that it would have been useful to have a zoomed out photo for better context.

It sounds like you had a mechanic do it for you so, naturally, there are a lot less things you would need to consider.

[rlesko]

Damn, I totally forgot to check for this over the weekend when I replaced my transmission mounts.

[Polo08816]

Originally Posted by rlesko

Damn, I totally forgot to check for this over the weekend when I replaced my transmission mounts.

I have my QuickJack out because I was working on another car this weekend. I'll try to get my 335i on it sometime in the next 2 days. I hate setting up and putting back my 7000TLX for just 1 car's worth of work lol.

[rlesko]

Originally Posted by Polo08816

I have my QuickJack out because I was working on another car this weekend. I'll try to get my 335i on it sometime in the next 2 days. I hate setting up and putting back my 7000TLX for just 1 car's worth of work lol.

that would be much appreciated! put this debate to rest! lol

[NxTH]

Originally Posted by rlesko

that would be much appreciated! put this debate to rest! lol

Sent the article writer from fcp euro an email a week ago, no answer. Commented on the new video they made asking about 335i, comment got removed.

[Polo08816]

Originally Posted by NxTH

Sent the article writer from fcp euro an email a week ago, no answer. Commented on the new video they made asking about 335i, comment got removed.

Your comment was removed?

That seems suspicious? How hard did you troll them?

[Eschmacher]

Regarding the location of this bolt, it appears to be on the front of my block, just below and to the left of the crank pulley.

This is someone else's pic off reddit, but it's the same location on mine. This is looking up from under the car, note the crank pulley location for reference.

https://i.redd.it/t3o92a8n9rq31.jpg

Edit: Screw it, here's my pic. It's dirty as hell because this is from right before my OFHG replacement. This is looking up from passenger side.

View post on imgur.com

[Polo08816]

Originally Posted by Eschmacher

Regarding the location of this bolt, it appears to be on the front of my block, just below and to the left of the crank pulley.

This is someone else's pic off reddit, but it's the same location on mine. This is looking up from under the car, note the crank pulley location for reference.

https://i.redd.it/t3o92a8n9rq31.jpg

Edit: Screw it, here's my pic. It's dirty as hell because this is from right before my OFHG replacement. This is looking up from passenger side.

View post on imgur.com

This is money!

As I thought, it is very different than the location that the FCP Euro blog post was referring to.

I've been under my car so many times for almost 10 years and I couldn't visualize where FCP Euro was saying that bolt was. The orientation of that bolt is completely different than what your two pictures demonstrate.